Programs & Examples On #Vim

Vim is a free and open-source modal text editor available for most major platforms. It allows high efficiency in many text editing tasks but has a steep learning curve. To learn the basics, run ":help vimtutor".

How do you delete all text above a certain line

:1,.d deletes lines 1 to current.
:1,.-1d deletes lines 1 to above current.

(Personally I'd use dgg or kdgg like the other answers, but TMTOWTDI.)

How to set default vim colorscheme

Once you’ve decided to change vim color scheme that you like, you’ll need to configure vim configuration file ~/.vimrc.

For e.g. to use the elflord color scheme just add these lines to your ~/.vimrc file:

colo elflord

For other names of color schemes you can look in /usr/share/vim/vimNN/colors where NN - version of VIM.

How do I change tab size in Vim?

Several of the answers on this page are 'single use' fixes to the described problem. Meaning, the next time you open a document with vim, the previous tab settings will return.

If anyone is interested in permanently changing the tab settings:

Find and replace strings in vim on multiple lines

We don't need to bother entering the current line number.

If you would like to change each foo to bar for current line (.) and the two next lines (+2), simply do:

:.,+2s/foo/bar/g

If you want to confirm before changes are made, replace g with gc:

:.,+2s/foo/bar/gc

How to save as a new file and keep working on the original one in Vim?

Thanks for the answers. Now I know that there are two ways of "SAVE AS" in Vim.

Assumed that I'm editing hello.txt.

  • :w world.txt will write hello.txt's content to the file world.txt while keeping hello.txt as the opened buffer in vim.
  • :sav world.txt will first write hello.txt's content to the file world.txt, then close buffer hello.txt, finally open world.txt as the current buffer.

Vim: faster way to select blocks of text in visual mode

You can press vi} to select the block surrounded with {} brackets where your cursor is currently located.

It doesn't really matter where you are inside that block (just make sure you are in the outermost one). Also you can change { to anything that has a pair like ) or ].

How do I exit from the text window in Git?

On windows, simply pressing 'q' on the keyboard quits this screen. I got it when I was reading help using '!help' or simply 'help' and 'enter', from the DOS prompt.

Happy Coding :-)

Working with huge files in VIM

I had the same problem, but it was a 300GB mysql dump and I wanted to get rid of the DROP and change CREATE TABLE to CREATE TABLE IF NOT EXISTS so didn't want to run two invocations of sed. I wrote this quick Ruby script to dupe the file with those changes:

#!/usr/bin/env ruby

matchers={
    %q/^CREATE TABLE `foo`/ => %q/CREATE TABLE IF NOT EXISTS `foo`/,
    %q/^DROP TABLE IF EXISTS `foo`;.*$/ => "-- DROP TABLE IF EXISTS `foo`;"
}

matchers.each_pair { |m,r|
    STDERR.puts "%s: %s" % [ m, r ]
}

STDIN.each { |line|
    #STDERR.puts "line=#{line}"
    line.chomp!
    unless matchers.length == 0
        matchers.each_pair { |m,r|
            re=/#{m}/
            next if line[re].nil?
            line.sub!(re,r)
            STDERR.puts "Matched: #{m} -> #{r}"
            matchers.delete(m)
            break
        }
    end
    puts line
}

Invoked like

./mreplace.rb < foo.sql > foo_two.sql

How to replace a character by a newline in Vim

You need to use:

:%s/,/^M/g

To get the ^M character, press Ctrl + v followed by Enter.

Tips for using Vim as a Java IDE?

I have just uploaded this Vim plugin for the development of Java Maven projects.

And don't forget to set the highlighting if you haven't already:

enter image description here https://github.com/sentientmachine/erics_vim_syntax_and_color_highlighting

How to do case insensitive search in Vim

As @huyz mention sometimes desired behavior is using case-insensitive searches but case-sensitive substitutions. My solution for that:

nnoremap / /\c
nnoremap ? ?\c

With that always when you hit / or ? it will add \c for case-insensitive search.

How to specify a editor to open crontab file? "export EDITOR=vi" does not work

This worked for me :

EDITOR="/usr/bin/vim"
export EDITOR

Add this to ~/.bash_profile or ~/.bashrc to enable this for current user.

Using git commit -a with vim

The better question is: How do I interrupt the commit when I quit vim?

There are 2 ways:

  1. :cq or :cquit
  2. Delete all lines of the commit message, including comments, and then :wq

Either way will give git an error code, so it will not proceed with the commit. This is particularly useful with git commit --amend.

Tab key == 4 spaces and auto-indent after curly braces in Vim

The auto-indent is based on the current syntax mode. I know that if you are editing Foo.java, then entering a { and hitting Enter indents the following line.

As for tabs, there are two settings. Within Vim, type a colon and then "set tabstop=4" which will set the tabs to display as four spaces. Hit colon again and type "set expandtab" which will insert spaces for tabs.

You can put these settings in a .vimrc (or _vimrc on Windows) in your home directory, so you only have to type them once.

Go to beginning of line without opening new line in VI

You can use ^ or 0 (Zero) in normal mode to move to the beginning of a line.

^ moves the cursor to the first non-blank character of a line
0 always moves the cursor to the "first column"

You can also use Shifti to move and switch to Insert mode.

How to view UTF-8 Characters in VIM or Gvim

In Linux, Open the VIM configuration file

$ sudo -H gedit /etc/vim/vimrc

Added following lines:

set fileencodings=utf-8,ucs-bom,gb18030,gbk,gb2312,cp936
set termencoding=utf-8
set encoding=utf-8

Save and exit, and terminal command:

$ source /etc/vim/vimrc

At this time VIM will correctly display Chinese.

"Find next" in Vim

As discussed, there are several ways to search:

/pattern
?pattern
* (and g*, which I sometimes use in macros)
# (and g#)

plus, navigating prev/next with N and n.

You can also edit/recall your search history by pulling up the search prompt with / and then cycle with C-p/C-n. Even more useful is q/, which takes you to a window where you can navigate the search history.

Also for consideration is the all-important 'hlsearch' (type :hls to enable). This makes it much easier to find multiple instances of your pattern. You might even want make your matches extra bright with something like:

hi Search ctermfg=yellow ctermbg=red guifg=...

But then you might go crazy with constant yellow matches all over your screen. So you’ll often find yourself using :noh. This is so common that a mapping is in order:

nmap <leader>z :noh<CR>

I easily remember this one as z since I used to constantly type /zz<CR> (which is a fast-to-type uncommon occurrence) to clear my highlighting. But the :noh mapping is way better.

Using Caps Lock as Esc in Mac OS X

I wasn't happy with any of the answers here, and went looking for a command-line solution.

In macOS Sierra 10.12, Apple introduced a new way for users to remap keys.

  • No need to fiddle around with system GUIs
  • No special privileges are required
  • Completely customisable
  • No need to install any 3rd-party crap like PCKeyboardHack / Seil / Karabiner / KeyRemap4MacBook / DoubleCommand / NoEjectDelay

If that sounds good to you, take a look at hidutil.

For example, to remap caps-lock to escape, refer to the key table and find that caps-lock has usage code 0x39 and escape has usage code 0x29. Put these codes or'd with the hex value 0x700000000 in the source and dest like this:

hidutil property --set '{"UserKeyMapping":[{"HIDKeyboardModifierMappingSrc":0x700000039,"HIDKeyboardModifierMappingDst":0x700000029}]}'

You may add other mappings in the same command. Personally, I like to remap caps-lock to backspace, and remap backspace to delete:

hidutil property --set '{"UserKeyMapping":[{"HIDKeyboardModifierMappingSrc":0x700000039,"HIDKeyboardModifierMappingDst":0x70000002A}, {"HIDKeyboardModifierMappingSrc":0x70000002A,"HIDKeyboardModifierMappingDst":0x70000004C}]}'

To see the current mapping:

hidutil property --get "UserKeyMapping"

Your changes will be lost at system reboot. If you want them to persist, configure them in a launch agent. Here's mine:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<!-- Place in ~/Library/LaunchAgents/ -->
<!-- launchctl load com.ldaws.CapslockBackspace.plist -->
<plist version="1.0">
  <dict>
    <key>Label</key>
    <string>com.ldaws.CapslockEsc</string>
    <key>ProgramArguments</key>
    <array>
      <string>/usr/bin/hidutil</string>
      <string>property</string>
      <string>--set</string>
      <string>{"UserKeyMapping":[{"HIDKeyboardModifierMappingSrc":0x700000039,"HIDKeyboardModifierMappingDst":0x70000002A},{"HIDKeyboardModifierMappingSrc":0x70000002A,"HIDKeyboardModifierMappingDst":0x70000004C}]}</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
  </dict>
</plist>

I've placed this content into a file located at ~/Library/LaunchAgents/com.ldaws.CapslockBackspace.plist and then executed:

launchctl load com.ldaws.CapslockBackspace.plist

Vim autocomplete for Python

As pointed out by in the comments, this answers is outdated. youcompleteme now supports python3 and jedi-vim no longer breaks the undo history.

Original answer below.


AFAIK there are three options, each with its disadvantages:

  1. youcompleteme: unfriendly to install, but works nice if you manage to get it working. However python3 is not supported.
  2. jedi-vim: coolest name, but breaks your undo history.
  3. python-mode does a lot more the autocomplete: folding, syntax checking, highlighting. Personally I prefer scripts that do 1 thing well, as they are easier to manage (and replace). Differently from the two other options, it uses rope instead of jedi for autocompletion.

Python 3 and undo history (gundo!) are a must for me, so options 1 and 2 are out.

What is Vim recording and how can it be disabled?

Type :h recording to learn more.

                           *q* *recording*
q{0-9a-zA-Z"}           Record typed characters into register {0-9a-zA-Z"}
                        (uppercase to append).  The 'q' command is disabled
                        while executing a register, and it doesn't work inside
                        a mapping.  {Vi: no recording}

q                       Stops recording.  (Implementation note: The 'q' that
                        stops recording is not stored in the register, unless
                        it was the result of a mapping)  {Vi: no recording}


                                                        *@*
@{0-9a-z".=*}           Execute the contents of register {0-9a-z".=*} [count]
                        times.  Note that register '%' (name of the current
                        file) and '#' (name of the alternate file) cannot be
                        used.  For "@=" you are prompted to enter an
                        expression.  The result of the expression is then
                        executed.  See also |@:|.  {Vi: only named registers}

What is the difference between MacVim and regular Vim?

The one reason I have which made switching to MacVim worth it: Yank uses the system clipboard.

I can finally copy paste between MacVim on my terminal and the rest of my applications.

How can I open a Shell inside a Vim Window?

I guess this is a fairly old question, but now in 2017. We have neovim, which is a fork of vim which adds terminal support.

So invoking :term would open a terminal window. The beauty of this solution as opposed to using tmux (a terminal multiplexer) is that you'll have the same window bindings as your vim setup. neovim is compatible with vim, so you can basically copy and paste your .vimrc and it will just work.

More advantages are you can switch to normal mode on the opened terminal and you can do basic copy and editing. It is also pretty useful for git commits too I guess, since everything in your buffer you can use in auto-complete.

I'll update this answer since vim is also planning to release terminal support, probably in vim 8.1. You can follow the progress here: https://groups.google.com/forum/#!topic/vim_dev/Q9gUWGCeTXM

Once it's released, I do believe this is a more superior setup than using tmux.

Is it possible to interactively delete matching search pattern in Vim?

There are 3 ways I can think of:

The way that is easiest to explain is

:%s/phrase to delete//gc

but you can also (personally I use this second one more often) do a regular search for the phrase to delete

/phrase to delete

Vim will take you to the beginning of the next occurrence of the phrase.

Go into insert mode (hit i) and use the Delete key to remove the phrase.

Hit escape when you have deleted all of the phrase.

Now that you have done this one time, you can hit n to go to the next occurrence of the phrase and then hit the dot/period "." key to perform the delete action you just performed

Continue hitting n and dot until you are done.

Lastly you can do a search for the phrase to delete (like in second method) but this time, instead of going into insert mode, you

Count the number of characters you want to delete

Type that number in (with number keys)

Hit the x key - characters should get deleted

Continue through with n and dot like in the second method.

PS - And if you didn't know already you can do a capital n to move backwards through the search matches.

go to character in vim

vim +21490go script.py

From the command line will open the file and take you to position 21490 in the buffer.

Triggering it from the command line like this allows you to automate a script to parse the exception message and open the file to the problem position.


Excerpt from man vim:

+{command}

-c {command}

{command} will be executed after the first file has been read. {command} is interpreted as an Ex command. If the {command} contains spaces it must be enclosed in double quotes (this depends on the shell that is used).

How to copy a selection to the OS X clipboard

Copying to clipboard using register '+' or '*' is not working?

Reason: Your particular version of vim was compiled without clipboard support.Type vim --verion on console and you will see -xterm_clipboard. Installing vim with gui packages solves this issue. On ubuntu you can do this by typing on shell:

sudo apt-get install vim-gui-common

Now again do vim --version on console. Most probably, you would be seeing +xterm_clipboard now!!

So, now you can copy anything to clipboard using register + (like "+yy to copy current line to clipboard)

To switch from vertical split to horizontal split fast in Vim

The following ex commands will (re-)split any number of windows:

  • To split vertically (e.g. make vertical dividers between windows), type :vertical ball
  • To split horizontally, type :ball

If there are hidden buffers, issuing these commands will also make the hidden buffers visible.

How do I use vim registers?

A big source of confusion is the default register ". It is important to know the way it works. It is much better if the default register is avoided most of the times. The explanation from the Vim documentation:

Vim fills this register with text deleted with the "d", "c", "s", "x" commands
or copied with the yank "y" command, regardless of whether or not a specific
register was used (e.g.  "xdd).  This is like the unnamed register is pointing
to the last used register.

So the default register is actually a pointer to the last used register. When you delete, or yank something this register is going to point to other registers. You can test that by checking the registers. There is always another register that is exactly the same as the default register: the yank register ("0) , the first delete register("1) , small delete register("-) or any other register that was used to delete or yank.

The only exception is the black hole register. Vim doc says:

An exception is the '_' register: "_dd does not store the deleted text in any
register.

Usually you are much better off by using directly: "0, "- and "1-"9 default registers or named registers.

Update built-in vim on Mac OS X

If I understand things correctly, you want to install over your existing Vim, for better or worse :-) This is a bad idea and it is not the "clean" way to do it. Why? Well, OS X expects that nothing will ever change in /usr/bin unbeknownst to it, so any time you overwrite stuff in there you risk breaking some intricate interdependency. And, Let's say you do break something -- there's no way to "undo" that damage. You will be sad and alone. You may have to reinstall OS X.

Part 1: A better idea

The "clean" way is to install in a separate place, and make the new binary higher priority in the $PATH. Here is how I recommend doing that:

$ # Create the directories you need
$ sudo mkdir -p /opt/local/bin
$ # Download, compile, and install the latest Vim
$ cd ~
$ hg clone https://bitbucket.org/vim-mirror/vim or git clone https://github.com/vim/vim.git
$ 
$ cd vim
$ ./configure --prefix=/opt/local
$ make
$ sudo make install
$ # Add the binary to your path, ahead of /usr/bin
$ echo 'PATH=/opt/local/bin:$PATH' >> ~/.bash_profile
$ # Reload bash_profile so the changes take effect in this window
$ source ~/.bash_profile

Voila! Now when we use vim we will be using the new one. But, to get back to our old configuration in the event of huge f*ckups, we can just delete the /opt directory.

$ which vim
/opt/local/bin/vim
$ vim --version | head -n 2
VIM - Vi IMproved 7.3 (2010 Aug 15, compiled Aug 27 2011 20:55:46)
MacOS X (unix) version

See how clean this is.

I recommend not to install in /usr/local/bin when you want to override binaries in /usr/bin, because by default OS X puts /usr/bin higher priority in $PATH than /usr/local/bin, and screwing with that opens its own can of worms.... So, that's what you SHOULD do.

Part 2: The "correct" answer (but a bad idea)

Assuming you're set on doing that, you are definitely on track. To install on top of your current installation, you need to set the "prefix" directory. That's done like this:

hg clone https://bitbucket.org/vim-mirror/vim or git clone https://github.com/vim/vim.git
cd vim
./configure --prefix=/usr
make
sudo make install

You can pass "configure" a few other options too, if you want. Do "./configure --help" to see them. I hope you've got a backup before you do it, though, in case something goes wrong....

How to run vi on docker container?

Inside container(in docker, not in VM), by default these are not installed. Even apt-get, wget will not work. My VM is running on Ubuntu 17.10. For me yum package manaager worked.

Yum is not part of debian or ubuntu. It is part of red-hat. But, it works in Ubuntu and it is installed by default like apt-get

Tu install vim, use this command

yum install -y vim-enhanced 

To uninstall vim :

yum uninstall -y vim-enhanced 

Similarly,

yum install -y wget 
yum install -y sudo 

-y is for assuming yes if prompted for any qustion asked after doing yum install packagename

What are the most-used vim commands/keypresses?

Here's a tip sheet I wrote up once, with the commands I actually use regularly:

References

General

  • Nearly all commands can be preceded by a number for a repeat count. eg. 5dd delete 5 lines
  • <Esc> gets you out of any mode and back to command mode
  • Commands preceded by : are executed on the command line at the bottom of the screen
  • :help help with any command

Navigation

  • Cursor movement: ?h ?j ?k l?
  • By words:
    • w next word (by punctuation); W next word (by spaces)
    • b back word (by punctuation); B back word (by spaces)
    • e end word (by punctuation); E end word (by spaces)
  • By line:
    • 0 start of line; ^ first non-whitespace
    • $ end of line
  • By paragraph:
    • { previous blank line; } next blank line
  • By file:
    • gg start of file; G end of file
    • 123G go to specific line number
  • By marker:
    • mx set mark x; 'x go to mark x
    • '. go to position of last edit
    • ' ' go back to last point before jump
  • Scrolling:
    • ^F forward full screen; ^B backward full screen
    • ^D down half screen; ^U up half screen
    • ^E scroll one line up; ^Y scroll one line down
    • zz centre cursor line

Editing

  • u undo; ^R redo
  • . repeat last editing command

Inserting

All insertion commands are terminated with <Esc> to return to command mode.

  • i insert text at cursor; I insert text at start of line
  • a append text after cursor; A append text after end of line
  • o open new line below; O open new line above

Changing

  • r replace single character; R replace multiple characters
  • s change single character
  • cw change word; C change to end of line; cc change whole line
  • c<motion> changes text in the direction of the motion
  • ci( change inside parentheses (see text object selection for more examples)

Deleting

  • x delete char
  • dw delete word; D delete to end of line; dd delete whole line
  • d<motion> deletes in the direction of the motion

Cut and paste

  • yy copy line into paste buffer; dd cut line into paste buffer
  • p paste buffer below cursor line; P paste buffer above cursor line
  • xp swap two characters (x to delete one character, then p to put it back after the cursor position)

Blocks

  • v visual block stream; V visual block line; ^V visual block column
    • most motion commands extend the block to the new cursor position
    • o moves the cursor to the other end of the block
  • d or x cut block into paste buffer
  • y copy block into paste buffer
  • > indent block; < unindent block
  • gv reselect last visual block

Global

  • :%s/foo/bar/g substitute all occurrences of "foo" to "bar"
    • % is a range that indicates every line in the file
    • /g is a flag that changes all occurrences on a line instead of just the first one

Searching

  • / search forward; ? search backward
  • * search forward for word under cursor; # search backward for word under cursor
  • n next match in same direction; N next match in opposite direction
  • fx forward to next character x; Fx backward to previous character x
  • ; move again to same character in same direction; , move again to same character in opposite direction

Files

  • :w write file to disk
  • :w name write file to disk as name
  • ZZ write file to disk and quit
  • :n edit a new file; :n! edit a new file without saving current changes
  • :q quit editing a file; :q! quit editing without saving changes
  • :e edit same file again (if changed outside vim)
  • :e . directory explorer

Windows

  • ^Wn new window
  • ^Wj down to next window; ^Wk up to previous window
  • ^W_ maximise current window; ^W= make all windows equal size
  • ^W+ increase window size; ^W- decrease window size

Source Navigation

  • % jump to matching parenthesis/bracket/brace, or language block if language module loaded
  • gd go to definition of local symbol under cursor; ^O return to previous position
  • ^] jump to definition of global symbol (requires tags file); ^T return to previous position (arbitrary stack of positions maintained)
  • ^N (in insert mode) automatic word completion

Show local changes

Vim has some features that make it easy to highlight lines that have been changed from a base version in source control. I have created a small vim script that makes this easy: http://github.com/ghewgill/vim-scmdiff

How can I make my match non greedy in vim?

With \v (as suggested in several comments)

:%s/\v(style|class)\=".{-}"//g

Go to first line in a file in vim?

Go to first line

  • :1

  • or Ctrl + Home

Go to last line

  • :%

  • or Ctrl + End


Go to another line (f.i. 27)

  • :27

[Works On VIM 7.4 (2016) and 8.0 (2018)]

How to run mvim (MacVim) from Terminal?

I'm adding Bard Park's comment here for that was the real answer for me:

Since mvim is simply a shell script, you can download it directly from the MacVim source at GitHub here: http://raw.github.com/b4winckler/macvim/master/src/MacVim/mvim

How to effectively work with multiple files in Vim

Many answers here! What I use without reinventing the wheel - the most famous plugins (that are not going to die any time soon and are used by many people) to be ultra fast and geeky.

  • ctrlpvim/ctrlp.vim - to find file by name fuzzy search by its location or just its name
  • jlanzarotta/bufexplorer - to browse opened buffers (when you do not remember how many files you opened and modified recently and you do not remember where they are, probably because you searched for them with Ag)
  • rking/ag.vim to search the files with respect to gitignore
  • scrooloose/nerdtree to see the directory structure, lookaround, add/delete/modify files

EDIT: Recently I have been using dyng/ctrlsf.vim to search with contextual view (like Sublime search) and I switched the engine from ag to ripgrep. The performance is outstanding.

EDIT2: Along with CtrlSF you can use mg979/vim-visual-multi, make changes to multiple files at once and then at the end save them in one go.

vi/vim editor, copy a block (not usual action)

Their Documentation says:

Cut and paste:

  1. Position the cursor where you want to begin cutting.
  2. Press v to select characters (or uppercase V to select whole lines).
  3. Move the cursor to the end of what you want to cut.
  4. Press d to cut (or y to copy).
  5. Move to where you would like to paste.
  6. Press P to paste before the cursor, or p to paste after.

Copy and paste is performed with the same steps except for step 4 where you would press y instead of d:

d = delete = cut

y = yank = copy

Why should I use an IDE?

I also almost exclusively use Vim (almost because I'm trying to learn emacs now) for all my development stuff. I think sheer intuitiveness (from the GUI of course) is the primary reason why people like to use IDEs. By being intuitive, little to no learning overhead of the tool is required. The lesser the learning overhead, the more they can get work done.

Replace tabs with spaces in vim

Try

set expandtab

for soft tabs.

To fix pre-existing tabs:

:%s/\t/  /g

I used two spaces since you already set your tabstop to 2 spaces.

See line breaks and carriage returns in editor

by using cat and -A you can see new lines as $, tabs as ^I
cat -A myfile

Vim delete blank lines

How about:

:g/^[ \t]*$/d

How to use vim in the terminal?

Get started quickly

You simply type vim into the terminal to open it and start a new file.

You can pass a filename as an option and it will open that file, e.g. vim main.c. You can open multiple files by passing multiple file arguments.

Vim has different modes, unlike most editors you have probably used. You begin in NORMAL mode, which is where you will spend most of your time once you become familiar with vim.

To return to NORMAL mode after changing to a different mode, press Esc. It's a good idea to map your Caps Lock key to Esc, as it's closer and nobody really uses the Caps Lock key.

The first mode to try is INSERT mode, which is entered with a for append after cursor, or i for insert before cursor.

To enter VISUAL mode, where you can select text, use v. There are many other variants of this mode, which you will discover as you learn more about vim.

To save your file, ensure you're in NORMAL mode and then enter the command :w. When you press :, you will see your command appear in the bottom status bar. To save and exit, use :x. To quit without saving, use :q. If you had made a change you wanted to discard, use :q!.

Configure vim to your liking

You can edit your ~/.vimrc file to configure vim to your liking. It's best to look at a few first (here's mine) and then decide which options suits your style.

This is how mine looks:

vim screenshot

To get the file explorer on the left, use NERDTree. For the status bar, use vim-airline. Finally, the color scheme is solarized.

Further learning

You can use man vim for some help inside the terminal. Alternatively, run vimtutor which is a good hands-on starting point.

It's a good idea to print out a Vim Cheatsheet and keep it in front of you while you're learning vim.

Good luck!

Shortcut to open file in Vim

If you're editing files in a common directory, you can :cd to that directory, then use :e on just the filename.

For example, rather than:

:e /big/long/path/that/takes/a/while/to/type/or/tab/complete/thingy.rb
:sp /big/long/path/that/takes/a/while/to/type/or/tab/complete/other_thingy.c
:vs /big/long/path/that/takes/a/while/to/type/or/tab/complete/one_more_thingy.java

You can do:

:cd /big/long/path/that/takes/a/while/to/type/or/tab/complete/
:e thingy.rb
:sp other_thingy.c
:vs one_more_thingy.java

Or, if you already have a file in the desired directory open, you can use the % shorthand for the current filename, and trim it to the current directory with the :h modifier (:help :_%:) :

:e /big/long/path/that/takes/a/while/to/type/or/tab/complete/thingy.rb
:cd %:h
:sp other_thingy.c
:vs one_more_thingy.java

And, like others have said, you can tab-complete file names on the ex-line (see :help cmdline-completion for more).

A more useful statusline in vim?

Here's mine:

set statusline=
set statusline +=%1*\ %n\ %*            "buffer number
set statusline +=%5*%{&ff}%*            "file format
set statusline +=%3*%y%*                "file type
set statusline +=%4*\ %<%F%*            "full path
set statusline +=%2*%m%*                "modified flag
set statusline +=%1*%=%5l%*             "current line
set statusline +=%2*/%L%*               "total lines
set statusline +=%1*%4v\ %*             "virtual column number
set statusline +=%2*0x%04B\ %*          "character under cursor

vim statusline

And here's the colors I used:

hi User1 guifg=#eea040 guibg=#222222
hi User2 guifg=#dd3333 guibg=#222222
hi User3 guifg=#ff66ff guibg=#222222
hi User4 guifg=#a0ee40 guibg=#222222
hi User5 guifg=#eeee40 guibg=#222222

How to stop line breaking in vim

It is correct that set nowrap will allow you to paste in a long line without vi/vim adding newlines, but then the line is not visually wrapped for easy reading. It is instead just one long line that you have to scroll through.

To have the line visually wrap but not have newline characters inserted into it, have set wrap (which is probably default so not needed to set) and set textwidth=0.

On some systems the setting of textwidth=0 is default. If you don't find that to be the case, add set textwidth=0 to your .exrc file so that it becomes your user's default for all vi/vim sessions.

Copy and paste content from one file to another file in vi

Example: fileA and fileB - start in fileA at line 25, copy 50 lines, and paste to fileB

fileA

Goto 25th line

25G

copy 50 lines into buffer v

"v50yy

Goto fileB

:e fileB

Goto line 10

10G    

paste contents of buffer v
"vp

Jump to function definition in vim

If everything is contained in one file, there's the command gd (as in 'goto definition'), which will take you to the first occurrence in the file of the word under the cursor, which is often the definition.

How to convert all text to lowercase in Vim

  1. If you really mean small caps, then no, that is not possible – just as it isn’t possible to convert text to bold or italic in any text editor (as opposed to word processor). If you want to convert text to lowercase, create a visual block and press u (or U to convert to uppercase). Tilde (~) in command mode reverses case of the character under the cursor.

  2. If you want to see all text in Vim in small caps, you might want to look at the guifont option, or type :set guifont=* if your Vim flavour supports GUI font chooser.

Auto-indent spaces with C in vim?

A lot of vim's features (like autoindent and cindent) are turned off by default. To really see what vim can do for you, you need a decent ~/.vimrc.

A good starter one is in $VIMRUNTIME/vimrc_example.vim. If you want to try it out, use

:source $VIMRUNTIME/vimrc_example.vim

when in vim.

I'd actually suggest just copying the contents to your ~/.vimrc as it's well commented, and a good place to start learning how to use vim. You can do this by

:e $VIMRUNTIME/vimrc_example.vim
:w! ~/.vimrc

This will overwrite your current ~/.vimrc, but if all you have in there is the indent settings Davr suggested, I wouldn't sweat it, as the example vimrc will take care of that for you as well. For a complete walkthrough of the example, and what it does for you, see :help vimrc-intro.

Copy all the lines to clipboard

:%y a Yanks all the content into vim's buffer, Pressing p in command mode will paste the yanked content after the line that your cursor is currently standing at.

How to jump back to NERDTree from file in tab?

ctrl-ww Could be useful when you have limited tabs open. But could get annoying when you have too many tabs open.

I type in :NERDTree again to get the focus back on NERDTree tab instantly wherever my cursor's focus is. Hope that helps

Highlight all occurrence of a selected word?

Enable search highlighting:

:set hlsearch

Then search for the word:

/word<Enter>

Using regular expressions to do mass replace in Notepad++ and Vim

In vim

:%s/<option value='.\{1,}' >//

or

:%s/<option value='.\+' >//

In vim regular expressions you have to escape the one-or-more symbol, capturing parentheses, the bounded number curly braces and some others.

See :help /magic to see which special characters need to be escaped (and how to change that).

How to open a new file in vim in a new window

Check out gVim. You can launch that in its own window.

gVim makes it really easy to manage multiple open buffers graphically.

You can also do the usual :e to open a new file, CTRL+^ to toggle between buffers, etc...

Another cool feature lets you open a popup window that lists all the buffers you've worked on.

This allows you to switch between open buffers with a single click.

To do this, click on the Buffers menu at the top and click the dotted line with the scissors.

enter image description here

Otherwise you can just open a new tab from your terminal session and launch vi from there.

You can usually open a new tab from terminal with CTRL+T or CTRL+ALT+T

Once vi is launched, it's easy to open new files and switch between them.

Running Python code in Vim

The accepted answer works for me (on Linux), but I wanted this command to also save the buffer before running, so I modified it slightly:

nnoremap <buffer> <F9> :w <bar> :exec '!python' shellescape(@%, 1)<cr>

The :w <bar> saves the buffer THEN runs the code in it.

How can I install MacVim on OS X?

  • Step 1. Install homebrew from here: http://brew.sh
  • Step 1.1. Run export PATH=/usr/local/bin:$PATH
  • Step 2. Run brew update
  • Step 3. Run brew install vim && brew install macvim
  • Step 4. Run brew link macvim

You now have the latest versions of vim and macvim managed by brew. Run brew update && brew upgrade every once in a while to upgrade them.

This includes the installation of the CLI mvim and the mac application (which both point to the same thing).

I use this setup and it works like a charm. Brew even takes care of installing vim with the preferable options.

What does ^M character mean in Vim?

Unix uses 0xA for a newline character. Windows uses a combination of two characters: 0xD 0xA. 0xD is the carriage return character. ^M happens to be the way vim displays 0xD (0x0D = 13, M is the 13th letter in the English alphabet).

You can remove all the ^M characters by running the following:

:%s/^M//g

Where ^M is entered by holding down Ctrl and typing v followed by m, and then releasing Ctrl. This is sometimes abbreviated as ^V^M, but note that you must enter it as described in the previous sentence, rather than typing it out literally.

This expression will replace all occurrences of ^M with the empty string (i.e. nothing). I use this to get rid of ^M in files copied from Windows to Unix (Solaris, Linux, OSX).

Differences between Emacs and Vim

I think the main difference is the design target. VIM is for UNIX as a working editor. Emacs is for GNU and lisp hackers, so it has some mixed design element.

I use vim on my workstation, while I love emacs too.

Vim multiline editing like in sublimetext?

Those are some good out-of-the box solutions given above, but we can also try some plugins which provide multiple cursors like Sublime.

I think this one looks promising:

It seemed abandoned for a while, but has had some contributions in 2014.

It is quite powerful, although it took me a little while to get used to the flow (which is quite Sublime-like but still modal like Vim).

In my experience if you have a lot of other plugins installed, you may meet some conflicts!

There are some others attempts at this feature:

Please feel free to edit if you notice any of these undergoing improvement.

How do I set the default font size in Vim?

Add Regular to syntax and use gfn:

set gfn= Monospace\ Regular:h13

Viewing all `git diffs` with vimdiff

You can try git difftool, it is designed to do this stuff.

First, you need to config diff tool to vimdiff

git config diff.tool vimdiff

Then, when you want to diff, just use git difftool instead of git diff. It will work as you expect.

How can I autoformat/indent C code in vim?

I like to use the program Artistic Style. According to their website:

Artistic Style is a source code indenter, formatter, and beautifier for the C, C++, C# and Java programming languages.

It runs in Window, Linux and Mac. It will do things like indenting, replacing tabs with spaces or vice-versa, putting spaces around operations however you like (converting if(x<2) to if ( x<2 ) if that's how you like it), putting braces on the same line as function definitions, or moving them to the line below, etc. All the options are controlled by command line parameters.

In order to use it in vim, just set the formatprg option to it, and then use the gq command. So, for example, I have in my .vimrc:

autocmd BufNewFile,BufRead *.cpp set formatprg=astyle\ -T4pb

so that whenever I open a .cpp file, formatprg is set with the options I like. Then, I can type gg to go to the top of the file, and gqG to format the entire file according to my standards. If I only need to reformat a single function, I can go to the top of the function, then type gq][ and it will reformat just that function.

The options I have for astyle, -T4pb, are just my preferences. You can look through their docs, and change the options to have it format the code however you like.

Here's a demo. Before astyle:

int main(){if(x<2){x=3;}}

float test()
{
if(x<2)
x=3;
}

After astyle (gggqG):

int main()
{
    if (x < 2)
    {
        x = 3;
    }
}

float test()
{
    if (x < 2)
        x = 3;
}

Hope that helps.

How to copy to clipboard in Vim?

selecting with the the help of the mouse and right-click copy worked in my case.

I didn't want the line numbers included so I :set nonumber before copying.

Changing case in Vim

Visual select the text, then U for uppercase or u for lowercase. To swap all casing in a visual selection, press ~ (tilde).

Without using a visual selection, gU<motion> will make the characters in motion uppercase, or use gu<motion> for lowercase.

For more of these, see Section 3 in Vim's change.txt help file.

How to comment out a block of Python code in Vim

There are some good plugins to help comment/uncomment lines. For example The NERD Commenter.

Vim 80 column layout concerns

this one is out of left field but its a nice little map for resizing your current split to 80 characters if you've got the line numbers on:

" make window 80 + some for numbers wide  
noremap <Leader>w :let @w=float2nr(log10(line("$")))+82\|:vertical resize <c-r>w<cr> 

Vim and Ctags tips and tricks

I've found the taglist plug-in a must-have. It lists all tags that it knows about (files that you have opened) in a seperate window and makes it very easy to navigate larger files.

I use it mostly for Python development, but it can only be better for C/C++.

How do I run a terminal inside of Vim?

This question is rather old, but for those finding it, there's a new possible solution: Neovim contains a full-fledged, first-class terminal emulator, which does exactly what ConqueTerm tried to. Simply run :term <your command here>.

<C-\><C-n> will exit term mode back to normal-mode. If you're like me and prefer that escape still exit term mode, you can add this to your nvimrc:

tnoremap <ESC><ESC> <C-\><C-N>

And then hitting ESC twice will exit terminal mode back to normal-mode, so you can manipulate the buffer that the still-running command is writing to.

Though keep in mind, as nvim is under heavy development at the time I'm posting this answer, another way to exit terminal mode may be added. As Ctrl+\Ctrl+n switches to normal mode from almost any mode, I don't expect that this answer will become wrong, but be aware that if it doesn't work, this answer might be out of date.

https://github.com/neovim/neovim

How do I install a plugin for vim?

Update (as 2019):

cd ~/.vim
git clone git://github.com/tpope/vim-haml.git pack/bundle/start/haml

Explanation (from :h pack ad :h packages):

  1. All the directories found are added to runtimepath. They must be in ~/.vim/pack/whatever/start [you can only change whatever].
  2. the plugins found in the plugins dir in runtimepath are sourced.

So this load the plugin on start (hence the name start).

You can also get optional plugin (loaded with :packadd) if you put them in ~/.vim/pack/bundle/opt

How do I switch between command and insert mode in Vim?

For me, the problem was that I was in recording mode. To exit from recording mode press q. Then Esc worked as expected for me.

How to copy selected lines to clipboard in vim

SHIFTV puts you in select lines mode. Then "*y yanks the currently selected lines to the * register which is the clipboard. There are quite a few different registers, for different purposes. See the section on selection and drop registers for details on the differences between * and + registers on Windows and Linux.

set gvim font in .vimrc file

When I try:

set guifont=Consolas:h16

I get: Warning: Font "Consolas" reports bad fixed pitch metrics

and the following is work, and don't show the waring.

autocmd vimenter * GuiFont! Consolas:h16

by the way, if you want to use the mouse wheel to control the font-size, then you can add:

function! AdjustFontSize(amount)
    let s:font_size = s:font_size + a:amount
    :execute "GuiFont! Consolas:h" . s:font_size
endfunction

noremap <C-ScrollWheelUp> :call AdjustFontSize(1)<CR>
noremap <C-ScrollWheelDown> :call AdjustFontSize(-1)<CR>

and if you want to pick the font, you can set

set guifont=*

will bring up a font requester, where you can pick the font you want.

enter image description here

VIM Disable Automatic Newline At End Of File

Starting with vim v7.4 you can use

:set nofixendofline

There is some information about that change here: http://ftp.vim.org/vim/patches/7.4/7.4.785 .

How to select between brackets (or quotes or ...) in Vim?

Write a Vim function in .vimrc using the searchpair built-in function:

searchpair({start}, {middle}, {end} [, {flags} [, {skip}
            [, {stopline} [, {timeout}]]]])
    Search for the match of a nested start-end pair.  This can be
    used to find the "endif" that matches an "if", while other
    if/endif pairs in between are ignored.
    [...]

(http://vimdoc.sourceforge.net/htmldoc/eval.html)

Autocompletion in Vim

I've just found the project Eclim linked in another question. This looks quite promising, at least for Java integration.

Why does Vim save files with a ~ extension?

I had to add set noundofile to ~_gvimrc

The "~" directory can be identified by changing the directory with the cd ~ command

What are the benefits of learning Vim?

I learned Vim. It wasn't too much effort. Now I absolutely love ci" ci( cw V:s/from/to/g

How do I fix the indentation of an entire file in Vi?

Before pasting into the terminal, try :set paste and then :set nopaste after you're done. This will turn off the auto-indent, line-wrap and other features that are messing up your paste.

edit: Also, I should point out that a much better result than = indenting can usually be obtained by using an external program. For example, I run :%!perltidy all the time. astyle, cindent, etc. can also be used. And, of course, you can map those to a key stroke, and map different ones to the same keystroke depending on file type.

How do I do redo (i.e. "undo undo") in Vim?

In command mode, use the U key to undo and Ctrl + r to redo. Have a look at http://www.vim.org/htmldoc/undo.html.

How to go back (ctrl+z) in vi/vim

Just in normal mode press:

  • u - undo,
  • Ctrl + r - redo changes which were undone (undo the undos).

Undo and Redo

How do you make Vim unhighlight what you searched for?

:noh (short for nohighlight) will do the trick.

Why does using from __future__ import print_function breaks Python2-style print?

First of all, from __future__ import print_function needs to be the first line of code in your script (aside from some exceptions mentioned below). Second of all, as other answers have said, you have to use print as a function now. That's the whole point of from __future__ import print_function; to bring the print function from Python 3 into Python 2.6+.

from __future__ import print_function

import sys, os, time

for x in range(0,10):
    print(x, sep=' ', end='')  # No need for sep here, but okay :)
    time.sleep(1)

__future__ statements need to be near the top of the file because they change fundamental things about the language, and so the compiler needs to know about them from the beginning. From the documentation:

A future statement is recognized and treated specially at compile time: Changes to the semantics of core constructs are often implemented by generating different code. It may even be the case that a new feature introduces new incompatible syntax (such as a new reserved word), in which case the compiler may need to parse the module differently. Such decisions cannot be pushed off until runtime.

The documentation also mentions that the only things that can precede a __future__ statement are the module docstring, comments, blank lines, and other future statements.

Copying text outside of Vim with set mouse=a enabled

I accidently explained how to switch off set mouse=a, when I reread the question and found out that the OP did not want to switch it off in the first place. Anyway for anyone searching how to switch off the mouse (set mouse=) centrally, I leave a reference to my answer here: https://unix.stackexchange.com/a/506723/194822

Delete newline in Vim

<CURSOR>Evaluator<T>():
    _bestPos(){
}

cursor in first line

NOW, in NORMAL MODE do

shift+v
2j
shift+j

or

V2jJ

:normal V2jJ

Why I've got no crontab entry on OS X when using vim?

Difference between cron and launchd

As has been mentioned cron is deprecated (but supported), and launchd is recommended for OS X.

This is taken from developer.apple.com

Effects of Sleeping and Powering Off

If the system is turned off or asleep, cron jobs do not execute; they will not run until the next designated time occurs.

If you schedule a launchd job by setting the StartCalendarInterval key and the computer is asleep when the job should have run, your job will run when the computer wakes up. However, if the machine is off when the job should have run, the job does not execute until the next designated time occurs.

All other launchd jobs are skipped when the computer is turned off or asleep; they will not run until the next designated time occurs.

Consequently, if the computer is always off at the job’s scheduled time, both cron jobs and launchd jobs never run. For example, if you always turn your computer off at night, a job scheduled to run at 1 A.M. will never be run.

What's a quick way to comment/uncomment lines in Vim?

I use vim 7.4 and this works for me.
Assuming we are commenting/uncommenting 3 lines.

To comment:

if the line has no tab/space at the beginning:
ctrl + V then jjj then shift + I (cappital i) then //then esc esc
if the line has tab/space at the beginning you still can do the above or swap for c:
ctrl + V then jjj then c then //then esc esc

To uncomment:

if the lines have no tab/space at the beginning:
ctrl + V then jjj then ll (lower cap L) then c

if the lines have tab/space at the beginning, then you space one over and esc
ctrl + V then jjj then ll (lower cap L) then c then space then esc

How to cut an entire line in vim and paste it?

Pressing Shift+v would select that entire line and pressing d would delete it.

You can also use dd, which is does not require you to enter visual mode.

Traversing text in Insert mode

You could use imap to map any key in insert mode to one of the cursor keys. Like so:

imap h <Left>

Now h works like in normal mode, moving the cursor. (Mapping h in this way is obviously a bad choice)

Having said that I do not think the standard way of moving around in text using VIM is "not productive". There are lots of very powerful ways of traversing the text in normal mode (like using w and b, or / and ?, or f and F, etc.)

Changing Vim indentation behavior by file type

This might be known by most of us, but anyway (I was puzzled my first time): Doing :set et (:set expandtabs) does not change the tabs already existing in the file, one has to do :retab. For example:

:set et
:retab

and the tabs in the file are replaced by enough spaces. To have tabs back simply do:

:set noet
:retab

How to insert tab character when expandtab option is on in Vim

You can use <CTRL-V><Tab> in "insert mode". In insert mode, <CTRL-V> inserts a literal copy of your next character.

If you need to do this often, @Dee`Kej suggested (in the comments) setting Shift+Tab to insert a real tab with this mapping:

:inoremap <S-Tab> <C-V><Tab>

Also, as noted by @feedbackloop, on Windows you may need to press <CTRL-Q> rather than <CTRL-V>.

How to duplicate a whole line in Vim?

yy or Y to copy the line (mnemonic: yank)
or
dd to delete the line (Vim copies what you deleted into a clipboard-like "register", like a cut operation)

then

p to paste the copied or deleted text after the current line
or
P to paste the copied or deleted text before the current line

How to make vim paste from (and copy to) system's clipboard?

On top of the setting :set clipboard=unnamed, you should use mvim -v which you can get with brew install macvim if you're using vim on Terminal.app on Mac OS X 10.9. Default vim does not support clipboard option.

How to temporarily exit Vim and go back

If you are on a Unix system, Ctrl + Z will suspend Vim and give you a shell.

Type fg to go back. Note that Vim creates a swap file while editing, and suspending Vim wouldn't delete that file (you aren't exiting Vim after all). On dumb terminals, this method was pretty standard for edit-compile-edit cycles using vi. I just found out that for me, gVim minimizes on typing Z.

Git commit in terminal opens VIM, but can't get back to terminal

not really the answer to the VIM problem but you could use the command line to also enter the commit message:

git commit -m "This is the first commit"

Move entire line up and down in Vim

:m.+1 or :m.-2 would do if you're moving a single line. Here's my script to move multiple lines. In visual mode, Alt-up/Alt-down will move the lines containing the visual selection up/down by one line. In insert mode or normal mode, Alt-up/Alt-down will move the current line if no count prefix is given. If there's a count prefix, Alt-up/Alt-down will move that many lines beginning from the current line up/down by one line.

function! MoveLines(offset) range
    let l:col = virtcol('.')
    let l:offset = str2nr(a:offset)
    exe 'silent! :' . a:firstline . ',' . a:lastline . 'm'
        \ . (l:offset > 0 ? a:lastline + l:offset : a:firstline + l:offset)
    exe 'normal ' . l:col . '|'
endf

imap <silent> <M-up> <C-O>:call MoveLines('-2')<CR>
imap <silent> <M-down> <C-O>:call MoveLines('+1')<CR>
nmap <silent> <M-up> :call MoveLines('-2')<CR>
nmap <silent> <M-down> :call MoveLines('+1')<CR>
vmap <silent> <M-up> :call MoveLines('-2')<CR>gv
vmap <silent> <M-down> :call MoveLines('+1')<CR>gv

How to comment in Vim's config files: ".vimrc"?

Same as above. Use double quote to start the comment and without the closing quote.

Example:

set cul "Highlight current line

How to select all and copy in vim?

In normal mode:

gg"+yG

In ex mode:

:%y+

Vim for Windows - What do I type to save and exit from a file?

Use:

:wq!

The exclamation mark is used for overriding read-only mode.

How to prevent vim from creating (and leaving) temporary files?

Put this in your .vimrc configuration file.

set nobackup

Setting up Vim for Python

Re: the dead "Turning Vim Into A Modern Python IDE" link, back in 2013 I saved a copy, that I converted to a HTML page as well as a PDF copy:

http://persagen.com/files/misc/Turning_vim_into_a_modern_Python_IDE.html

http://persagen.com/files/misc/Turning_vim_into_a_modern_Python_IDE.pdf

Edit (Sep 08, 2017) updated URLs.

How can I search an array in VB.NET?

This would do the trick, returning the values at indeces 0, 2 and 3.

Array.FindAll(arr, Function(s) s.ToLower().StartsWith("ra"))

Is it possible to output a SELECT statement from a PL/SQL block?

For versions below 12c, the plain answer is NO, at least not in the manner it is being done is SQL Server.
You can print the results, you can insert the results into tables, you can return the results as cursors from within function/procedure or return a row set from function -
but you cannot execute SELECT statement, without doing something with the results.


SQL Server

begin
    select 1+1
    select 2+2
    select 3+3
end

/* 3 result sets returned */


Oracle

SQL> begin
  2  select 1+1 from dual;
  3  end;
  4  /
select * from dual;
*
ERROR at line 2:
ORA-06550: line 2, column 1:
PLS-00428: an INTO clause is expected in this SELECT statement

Python open() gives FileNotFoundError/IOError: Errno 2 No such file or directory

If is VSCode see the workspace. If you are in other workspace this error can rise

No tests found with test runner 'JUnit 4'

My problem was that declaration import org.junit.Test; has disappeared (or wasn't added?). After adding it, I had to remove another import declaration (Eclipse'll hint you which one) and everything began to work again.

search in java ArrayList

You're missing the return statement because if your list size is 0, the for loop will never execute, thus the if will never run, and thus you will never return.

Move the if statement out of the loop.

Extracting the top 5 maximum values in excel

There 3 functions you want to look at here:

I ran a sample in Excel with your OPS values in Column B and Players in Column C, see below:

Excel sample

  • In Cells A13 to A17, the values 1 to 5 were inserted to specify the nth highest value.
  • In Cell B13, the following formula was added: =LARGE($B$2:$B$11, A13)
  • In Cell C13, the following formula was added: =INDEX($C$2:$C$11,MATCH(B13,$B$2:$B$11,0))
  • These formulae get the highest ranking OPS and Player based on the value in A13.
  • Simply select and drag to copy these formulae down to the next 4 cells which will reference the corresponding ranking in Column A.

Convert Select Columns in Pandas Dataframe to Numpy Array

the easy way is the "values" property df.iloc[:,1:].values

a=df.iloc[:,1:]
b=df.iloc[:,1:].values

print(type(df))
print(type(a))
print(type(b))

so, you can get type

<class 'pandas.core.frame.DataFrame'>
<class 'pandas.core.frame.DataFrame'>
<class 'numpy.ndarray'>

Meaning of ${project.basedir} in pom.xml

${project.basedir} is the root directory of your project.

${project.build.directory} is equivalent to ${project.basedir}/target

as it is defined here: https://github.com/apache/maven/blob/trunk/maven-model-builder/src/main/resources/org/apache/maven/model/pom-4.0.0.xml#L53

Android MediaPlayer Stop and Play

just in case someone comes to this question, I have the easier version.

public static MediaPlayer mp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button b = (Button) findViewById(R.id.button);
        Button b2 = (Button) findViewById(R.id.button2);


        b.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                mp = MediaPlayer.create(MainActivity.this, R.raw.game);
                mp.start();
            }
        });

        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mp.stop();
               // mp.start();
            }
        });
    }

How can I get color-int from color resource?

Based on the new Android Support Library (and this update), now you should call:

ContextCompat.getColor(context, R.color.name.color);

According to the documentation:

public int getColor (int id)

This method was deprecated in API level 23. Use getColor(int, Theme) instead

It is the same solution for getResources().getColorStateList(id):

You have to change it like this:

ContextCompat.getColorStateList(getContext(),id);

EDIT 2019

Regarding ThemeOverlay use the context of the closest view:

val color = ContextCompat.getColor(
  closestView.context,
  R.color.name.color
)

So this way you get the right color based on your ThemeOverlay.

Specially needed when in same activity you use different themes, like dark/light theme. If you would like to understand more about Themes and Styles this talk is suggested: Developing Themes with Style

Nick Butcher - Droidcon Berlin - Developing Themes with Style

Convert JSON string to dict using Python

When I started using json, I was confused and unable to figure it out for some time, but finally I got what I wanted
Here is the simple solution

import json
m = {'id': 2, 'name': 'hussain'}
n = json.dumps(m)
o = json.loads(n)
print(o['id'], o['name'])

How do you compare structs for equality in C?

@Greg is correct that one must write explicit comparison functions in the general case.

It is possible to use memcmp if:

  • the structs contain no floating-point fields that are possibly NaN.
  • the structs contain no padding (use -Wpadded with clang to check this) OR the structs are explicitly initialized with memset at initialization.
  • there are no member types (such as Windows BOOL) that have distinct but equivalent values.

Unless you are programming for embedded systems (or writing a library that might be used on them), I would not worry about some of the corner cases in the C standard. The near vs. far pointer distinction does not exist on any 32- or 64- bit device. No non-embedded system that I know of has multiple NULL pointers.

Another option is to auto-generate the equality functions. If you lay your struct definitions out in a simple way, it is possible to use simple text processing to handle simple struct definitions. You can use libclang for the general case – since it uses the same frontend as Clang, it handles all corner cases correctly (barring bugs).

I have not seen such a code generation library. However, it appears relatively simple.

However, it is also the case that such generated equality functions would often do the wrong thing at application level. For example, should two UNICODE_STRING structs in Windows be compared shallowly or deeply?

Transform only one axis to log10 scale with ggplot2

I think I got it at last by doing some manual transformations with the data before visualization:

d <- diamonds
# computing logarithm of prices
d$price <- log10(d$price)

And work out a formatter to later compute 'back' the logarithmic data:

formatBack <- function(x) 10^x 
# or with special formatter (here: "dollar")
formatBack <- function(x) paste(round(10^x, 2), "$", sep=' ') 

And draw the plot with given formatter:

m <- ggplot(d, aes(y = price, x = color))
m + geom_boxplot() + scale_y_continuous(formatter='formatBack')

alt text

Sorry to the community to bother you with a question I could have solved before! The funny part is: I was working hard to make this plot work a month ago but did not succeed. After asking here, I got it.

Anyway, thanks to @DWin for motivation!

Link to "pin it" on pinterest without generating a button

For such cases, I found very useful the Share Link Generator, it helps creating Facebook, Google+, Twitter, Pinterest, LinkedIn share buttons.

How can you zip or unzip from the script using ONLY Windows' built-in capabilities?

I have a problem with all these solutions.

They're not exactly the same, and they all create files that have a slight size difference compared to the RMB --> send to --> compressed (zipped) folder when made from the same source folder. The closest size-difference I have had is 300 KB difference (script > manual), made with:

powershell Compress-Archive -Path C:\sourceFolder -CompressionLevel Fastest -DestinationPath C:\destinationArchive.zip

(Notice the -CompressionLevel. There are three possible values: Fastest, NoCompression & Optimal, (Default: Optimal))

I wanted to make a .bat file that should automatically compress a WordPress plugin folder I'm working on, into a .zip archive, so I can upload it into the WordPress site and test the plugin.

But for some reason it doesn't work with any of these automatic compressions, but it does work with the manual RMB compression, witch I find really strange.

And the script-generated .zip files actually break the WordPress plugins to the point where they can't be activated, and they can also not be deleted from inside WordPress. I have to SSH into the "back side" of the server and delete the uploaded plugin files themselves, manually. While the manually RMB-generated files work normally.

What is the equivalent of "!=" in Excel VBA?

In VBA, the != operator is the Not operator, like this:

If Not strTest = "" Then ...

aspx page to redirect to a new page

Darin's answer works great. It creates a 302 redirect. Here's the code modified so that it creates a permanent 301 redirect:

<%@ Page Language="C#" %>
<script runat="server">
  protected override void OnLoad(EventArgs e)
  {
      Response.RedirectPermanent("new.aspx");
      base.OnLoad(e);
  }
</script>

What's the difference between Cache-Control: max-age=0 and no-cache?

One thing that (surprisingly) hasn't been mentioned is that a request can explicitly indicate that it will accept stale data, using the max-stale directive. In that case, if the server responded with max-age=0, the cache would merely consider the response stale, and would be free to use it to satisfy the client's request [which asked for potentially-stale data]. By contrast, if the server sends no-cache that really does trump any request by the client (with max-stale) for stale data, as the cache MUST revalidate.

How to force page refreshes or reloads in jQuery?

You don't need jQuery to do this. Embrace the power of JavaScript.

window.location.reload()

SVN Repository Search

Update January, 2020

VisualSVN Server 4.2 supports finding files and folders in the web interface. Try out the new feature on one of the demo server’s repositories!

See the version 4.2 Release Notes, and download VisualSVN Server 4.2.0 from the main download page.

enter image description here


Old answer

Beginning with Subversion 1.8, you can use --search option with svn log command. Note that the command does not perform full-text search inside a repository, it considers the following data only:

  • revision's author (svn:author unversioned property),
  • date (svn:date unversioned property),
  • log message text (svn:log unversioned property),
  • list of changed paths (i.e. paths affected by the particular revision).

Here is the help page about these new search options:

 If the --search option is used, log messages are displayed only if the
 provided search pattern matches any of the author, date, log message
 text (unless --quiet is used), or, if the --verbose option is also
 provided, a changed path.
 The search pattern may include "glob syntax" wildcards:
     ?      matches any single character
     *      matches a sequence of arbitrary characters
     [abc]  matches any of the characters listed inside the brackets
 If multiple --search options are provided, a log message is shown if
 it matches any of the provided search patterns. If the --search-and
 option is used, that option's argument is combined with the pattern
 from the previous --search or --search-and option, and a log message
 is shown only if it matches the combined search pattern.
 If --limit is used in combination with --search, --limit restricts the
 number of log messages searched, rather than restricting the output
 to a particular number of matching log messages.

How to write to file in Ruby?

For those of us that learn by example...

Write text to a file like this:

IO.write('/tmp/msg.txt', 'hi')

BONUS INFO ...

Read it back like this

IO.read('/tmp/msg.txt')

Frequently, I want to read a file into my clipboard ***

Clipboard.copy IO.read('/tmp/msg.txt')

And other times, I want to write what's in my clipboard to a file ***

IO.write('/tmp/msg.txt', Clipboard.paste)

*** Assumes you have the clipboard gem installed

See: https://rubygems.org/gems/clipboard

How to check SQL Server version

TL;DR

SQLCMD -S (LOCAL) -E -V 16 -Q "IF(ISNULL(CAST(SERVERPROPERTY('ProductMajorVersion') AS INT),0)<11) RAISERROR('You need SQL 2012 or later!',16,1)"
IF ERRORLEVEL 1 GOTO :ExitFail

This uses SQLCMD (comes with SQL Server) to connect to the local server instance using Windows auth, throw an error if a version check fails and return the @@ERROR as the command line ERRORLEVEL if >= 16 (and the second line goes to the :ExitFail label if the aforementioned ERRORLEVEL is >= 1).

Watchas, Gotchas & More Info

For SQL 2000+ you can use the SERVERPROPERTY to determine a lot of this info.

While SQL 2008+ supports the ProductMajorVersion & ProductMinorVersion properties, ProductVersion has been around since 2000 (remembering that if a property is not supported the function returns NULL).

If you are interested in earlier versions you can use the PARSENAME function to split the ProductVersion (remembering the "parts" are numbered right to left i.e. PARSENAME('a.b.c', 1) returns c).

Also remember that PARSENAME('a.b.c', 4) returns NULL, because SQL 2005 and earlier only used 3 parts in the version number!

So for SQL 2008+ you can simply use:

SELECT
    SERVERPROPERTY('ProductVersion') AS ProductVersion,
    CAST(SERVERPROPERTY('ProductMajorVersion')  AS INT) AS ProductMajorVersion,
    CAST(SERVERPROPERTY ('ProductMinorVersion') AS INT) AS ProductMinorVersion;

For SQL 2000-2005 you can use:

SELECT
    SERVERPROPERTY('ProductVersion') AS ProductVersion,
    CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 3 ELSE 4 END) AS INT) AS ProductVersion_Major,
    CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 2 ELSE 3 END) AS INT) AS ProductVersion_Minor,
    CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 1 ELSE 2 END) AS INT) AS ProductVersion_Revision,
    CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 0 ELSE 1 END) AS INT) AS ProductVersion_Build;

(the PARSENAME(...,0) is a hack to improve readability)

So a check for a SQL 2000+ version would be:

IF (CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 3 ELSE 4 END) AS INT) < 10) -- SQL2008
OR (
    (CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 3 ELSE 4 END) AS INT) = 10) -- SQL2008
AND (CAST(PARSENAME(CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME), CASE WHEN SERVERPROPERTY('ProductVersion') IS NULL THEN 2 ELSE 1 END) AS INT) < 5)  -- R2 (this may need to be 50)
   )
    RAISERROR('You need SQL 2008R2 or later!', 16, 1);

This is a lot simpler if you're only only interested in SQL 2008+ because SERVERPROPERTY('ProductMajorVersion') returns NULL for earlier versions, so you can use:

IF (ISNULL(CAST(SERVERPROPERTY('ProductMajorVersion') AS INT), 0) < 11) -- SQL2012
    RAISERROR('You need SQL 2012 or later!', 16, 1);

And you can use the ProductLevel and Edition (or EngineEdition) properties to determine RTM / SPn / CTPn and Dev / Std / Ent / etc respectively.

SELECT
    CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME) AS ProductVersion,
    CAST(SERVERPROPERTY('ProductLevel') AS SYSNAME)   AS ProductLevel,
    CAST(SERVERPROPERTY('Edition') AS SYSNAME)        AS Edition,
    CAST(SERVERPROPERTY('EngineEdition') AS INT)      AS EngineEdition;

FYI the major SQL version numbers are:

  • 8 = SQL 2000
  • 9 = SQL 2005
  • 10 = SQL 2008 (and 10.5 = SQL 2008R2)
  • 11 = SQL 2012
  • 12 = SQL 2014
  • 13 = SQL 2016
  • 14 = SQL 2017

And this all works for SQL Azure too!

EDITED: You may also want to check your DB compatibility level since it could be set to a lower compatibility.

IF EXISTS (SELECT * FROM sys.databases WHERE database_id=DB_ID() AND [compatibility_level] < 110)
    RAISERROR('Database compatibility level must be SQL2008R2 or later (110)!', 16, 1)

What is the order of precedence for CSS?

What we are looking at here is called specificity as stated by Mozilla:

Specificity is the means by which browsers decide which CSS property values are the most relevant to an element and, therefore, will be applied. Specificity is based on the matching rules which are composed of different sorts of CSS selectors.

Specificity is a weight that is applied to a given CSS declaration, determined by the number of each selector type in the matching selector. When multiple declarations have equal specificity, the last declaration found in the CSS is applied to the element. Specificity only applies when the same element is targeted by multiple declarations. As per CSS rules, directly targeted elements will always take precedence over rules which an element inherits from its ancestor.

I like the 0-0-0 explanation at https://specifishity.com:

enter image description here

Quite descriptive the picture of the !important directive! But sometimes it's the only way to override the inline style attribute. So it's a best practice trying to avoid both.

UITableView set to static cells. Is it possible to hide some of the cells programmatically?

Solution from k06a (https://github.com/k06a/ABStaticTableViewController) is better because it hides whole section including cells headers and footers, where this solution (https://github.com/peterpaulis/StaticDataTableViewController) hides everything except footer.

EDIT

I just found solution if you want to hide footer in StaticDataTableViewController. This is what you need to copy in StaticTableViewController.m file:

- (NSString *)tableView:(UITableView *)tableView titleForFooterInSection:(NSInteger)section {
    if ([tableView.dataSource tableView:tableView numberOfRowsInSection:section] == 0) {
        return nil;
    } else {
        return [super tableView:tableView titleForFooterInSection:section];
    }
}

- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {

    CGFloat height = [super tableView:tableView heightForFooterInSection:section];

    if (self.originalTable == nil) {
        return height;
    }

    if (!self.hideSectionsWithHiddenRows) {
        return height;
    }

    OriginalSection * os = self.originalTable.sections[section];
    if ([os numberOfVissibleRows] == 0) {
       //return 0;
        return CGFLOAT_MIN;
    } else {
        return height;
    }

    //return 0;
    return CGFLOAT_MIN;
}

Custom Cell Row Height setting in storyboard is not responding

The same problem occurred when working on XCode 9 using Swift 4.

Add AutoLayout for the UI elements inside the Cell and custom cell row height will work accordingly as specified.

Java: How to Indent XML Generated by Transformer

You need to enable 'INDENT' and set the indent amount for the transformer:

t.setOutputProperty(OutputKeys.INDENT, "yes");
t.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");

Update:


Reference : How to strip whitespace-only text nodes from a DOM before serialization?

(Many thanks to all members especially @marc-novakowski, @james-murty and @saad):

Case Statement Equivalent in R

Have a look at the cases function from the memisc package. It implements case-functionality with two different ways to use it. From the examples in the package:

z1=cases(
    "Condition 1"=x<0,
    "Condition 2"=y<0,# only applies if x >= 0
    "Condition 3"=TRUE
    )

where x and y are two vectors.

References: memisc package, cases example

Upload files from Java client to a HTTP server

protected void doPost(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {

    boolean isMultipart = ServletFileUpload.isMultipartContent(request);

    if (!isMultipart) {
        return;
    }

    DiskFileItemFactory factory = new DiskFileItemFactory();

    factory.setSizeThreshold(MAX_MEMORY_SIZE);

    factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

    String uploadFolder = getServletContext().getRealPath("")
            + File.separator + DATA_DIRECTORY;//DATA_DIRECTORY is directory where you upload this file on the server

    ServletFileUpload upload = new ServletFileUpload(factory);

    upload.setSizeMax(MAX_REQUEST_SIZE);//MAX_REQUEST_SIZE is the size which size you prefer

And use <form enctype="multipart/form-data"> and use <input type="file"> in the html

TypeScript: Creating an empty typed container array

The existing answers missed an option, so here's a complete list:

// 1. Explicitly declare the type
var arr: Criminal[] = [];

// 2. Via type assertion
var arr = <Criminal[]>[];
var arr = [] as Criminal[];

// 3. Using the Array constructor
var arr = new Array<Criminal>();
  1. Explicitly specifying the type is the general solution for whenever type inference fails for a variable declaration.

  2. The advantage of using a type assertion (sometimes called a cast, but it's not really a cast in TypeScript) works for any expression, so it can be used even when no variable is declared. There are two syntaxes for type assertions, but only the latter will work in combination with JSX if you care about that.

  3. Using the Array constructor is something that will only help you in this specific use case, but which I personally find the most readable. However, there is a slight performance impact at runtime*. Also, if someone were crazy enough to redefine the Array constructor, the meaning could change.

It's a matter of personal preference, but I find the third option the most readable. In the vast majority of cases the mentioned downsides would be negligible and readability is the most important factor.

*: Fun fact; at the time of writing the performance difference was 60% in Chrome, while in Firefox there was no measurable performance difference.

How to append text to a text file in C++?

I got my code for the answer from a book called "C++ Programming In Easy Steps". The could below should work.

#include <fstream>
#include <string>
#include <iostream>

using namespace std;

int main()
{
    ofstream writer("filename.file-extension" , ios::app);

    if (!writer)
    {
        cout << "Error Opening File" << endl;
        return -1;
    }

    string info = "insert text here";
    writer.append(info);

    writer << info << endl;
    writer.close;
    return 0;   
} 

I hope this helps you.

npm not working after clearing cache

Environment path may have been removed.

Check it by typing,

npm config get prefix

This must be the location where the npm binaries are found.

In windows, c:/users/username/AppData/Roaming/npm is the place where they are found.

Add this location to the environment variable. It should work fine.

(Control Panel -> Search for 'Environment Variables' and click on a button with that name -> edit Path -> add the above location)

splitting a number into the integer and decimal parts

Use math.modf:

import math
x = 1234.5678
math.modf(x) # (0.5678000000000338, 1234.0)

How to read xml file contents in jQuery and display in html elements?

You can use $.each()

Suppose your xml is

<Cloudtags><id>1</id></Cloudtags><Cloudtags><id>2</id></Cloudtags><Cloudtags><id>3</id></Cloudtags>

In your Ajax success

success: function (xml) {
    $(xml).find('Cloudtags').each(function(){// your outer tag of xml
         var id = $(this).find("id").text(); // 
    });
}

For your case

success: function (xml) {
        $(xml).find('person').each(function(){// your outer tag of xml
             var name = $(this).find("name").text(); // 
             var age = $(this).find("age").text();
        });
    }

Links in <select> dropdown options

Add an onchange event handler and set the pages location to the value

<select id="foo">
    <option value="">Pick a site</option>
    <option value="http://www.google.com">x</option>
    <option value="http://www.yahoo.com">y</option>
</select>

<script>
    document.getElementById("foo").onchange = function() {
        if (this.selectedIndex!==0) {
            window.location.href = this.value;
        }        
    };
</script>

installing vmware tools: location of GCC binary?

First execute this

sudo apt-get install gcc binutils make linux-source

Then run again

/usr/bin/vmware-config-tools.pl

This is all you need to do. Now your system has the gcc make and the linux kernel sources.

reactjs giving error Uncaught TypeError: Super expression must either be null or a function, not undefined

Class Names

Firstly, if you're certain that you're extending from the correctly named class, e.g. React.Component, not React.component or React.createComponent, you may need to upgrade your React version. See answers below for more information on the classes to extend from.

Upgrade React

React has only supported ES6-style classes since version 0.13.0 (see their official blog post on the support introduction here.

Before that, when using:

class HelloMessage extends React.Component

you were attempting to use ES6 keywords (extends) to subclass from a class which wasn't defined using ES6 class. This was likely why you were running into strange behaviour with super definitions etc.

So, yes, TL;DR - update to React v0.13.x.

Circular Dependencies

This can also occur if you have circular import structure. One module importing another and the other way around. In this case you just need to refactor your code to avoid it. More info

Select a row from html table and send values onclick of a button

This below code will give selected row, you can parse the values from it and send to the AJAX call.

$(".selected").click(function () {
var row = $(this).parent().parent().parent().html();            
});

Count records for every month in a year

SELECT    COUNT(*) 
FROM      table_emp 
WHERE     YEAR(ARR_DATE) = '2012' 
GROUP BY  MONTH(ARR_DATE)

How to get single value from this multi-dimensional PHP array

Look at the keys and indentation in your print_r:

echo $myarray[0]['email'];

echo $myarray[0]['gender'];

...etc

Error in eval(expr, envir, enclos) : object not found

This can happen if you don't attach your dataset.

Multiple INNER JOIN SQL ACCESS

Access requires parentheses in the FROM clause for queries which include more than one join. Try it this way ...

FROM
    ((tbl_employee
    INNER JOIN tbl_netpay
    ON tbl_employee.emp_id = tbl_netpay.emp_id)
    INNER JOIN tbl_gross
    ON tbl_employee.emp_id = tbl_gross.emp_ID)
    INNER JOIN tbl_tax
    ON tbl_employee.emp_id = tbl_tax.emp_ID;

If possible, use the Access query designer to set up your joins. The designer will add parentheses as required to keep the db engine happy.

How to find out mySQL server ip address from phpmyadmin

The SQL query SHOW VARIABLES WHERE Variable_name = 'hostname' will show you the hostname of the MySQL server which you can easily resolve to its IP address.

SHOW VARIABLES WHERE Variable_name = 'port' Will give you the port number.

You can find details about this in MySQL's manual: 12.4.5.41. SHOW VARIABLES Syntax and 5.1.4. Server System Variables

Open a facebook link by native Facebook app on iOS

If the Facebook application is logged in, the page will be opened when executing the following code. If the Facebook application is not logged in when executing the code, the user will then be redirected to the Facebook app to login and then after connecting the Facebook is not redirected to the page!

NSURL *fbNativeAppURL = [NSURL URLWithString:@"fb://page/yourPageIDHere"] [[UIApplication sharedApplication] openURL:fbNativeAppURL]

Official way to ask jQuery wait for all images to load before executing something

My solution is similar to molokoloco. Written as jQuery function:

$.fn.waitForImages = function (callback) {
    var $img = $('img', this),
        totalImg = $img.length;

    var waitImgLoad = function () {
        totalImg--;
        if (!totalImg) {
            callback();
        }
    };

    $img.each(function () {
        if (this.complete) { 
            waitImgLoad();
        }
    })

    $img.load(waitImgLoad)
        .error(waitImgLoad);
};

example:

<div>
    <img src="img1.png"/>
    <img src="img2.png"/>
</div>
<script>
    $('div').waitForImages(function () {
        console.log('img loaded');
    });
</script>

Using multiprocessing.Process with a maximum number of simultaneous processes

more generally, this could also look like this:

import multiprocessing
def chunks(l, n):
    for i in range(0, len(l), n):
        yield l[i:i + n]

numberOfThreads = 4


if __name__ == '__main__':
    jobs = []
    for i, param in enumerate(params):
        p = multiprocessing.Process(target=f, args=(i,param))
        jobs.append(p)
    for i in chunks(jobs,numberOfThreads):
        for j in i:
            j.start()
        for j in i:
            j.join()

Of course, that way is quite cruel (since it waits for every process in a junk until it continues with the next chunk). Still it works well for approx equal run times of the function calls.

IP to Location using Javascript

You can submit the IP you receive to an online geolocation service, such as http://www.geoplugin.net/json.gp?ip=<your ip here>&jsoncallback=<suitable javascript function in your source>, then including the source it returns which will run the function you specify in jsoncallback with the geolocation information.

Alternatively, you may want to look into HTML5's geolocation features -- you can see a demo of it in action here. The advantage of this is that you do not need to make requests to foreign servers, but it may not work on browsers that do not support HTML5.

How to create a directory and give permission in single command

Don't do: mkdir -m 777 -p a/b/c since that will only set permission 777 on the last directory, c; a and b will be created with the default permission from your umask.

Instead to create any new directories with permission 777, run mkdir -p in a subshell where you override the umask:

(umask u=rwx,g=rwx,o=rwx && mkdir -p a/b/c)

Note that this won't change the permissions if any of a, b and c already exist though.

Implicit type conversion rules in C++ operators

The type of the expression, when not both parts are of the same type, will be converted to the biggest of both. The problem here is to understand which one is bigger than the other (it does not have anything to do with size in bytes).

In expressions in which a real number and an integer number are involved, the integer will be promoted to real number. For example, in int + float, the type of the expression is float.

The other difference are related to the capability of the type. For example, an expression involving an int and a long int will result of type long int.

How do I output coloured text to a Linux terminal?

Basics

I have written a C++ class which can be used to set the foreground and background color of output. This sample program serves as an example of printing This ->word<- is red. and formatting it so that the foreground color of word is red.

#include "colormod.h" // namespace Color
#include <iostream>
using namespace std;
int main() {
    Color::Modifier red(Color::FG_RED);
    Color::Modifier def(Color::FG_DEFAULT);
    cout << "This ->" << red << "word" << def << "<- is red." << endl;
}

Source

#include <ostream>
namespace Color {
    enum Code {
        FG_RED      = 31,
        FG_GREEN    = 32,
        FG_BLUE     = 34,
        FG_DEFAULT  = 39,
        BG_RED      = 41,
        BG_GREEN    = 42,
        BG_BLUE     = 44,
        BG_DEFAULT  = 49
    };
    class Modifier {
        Code code;
    public:
        Modifier(Code pCode) : code(pCode) {}
        friend std::ostream&
        operator<<(std::ostream& os, const Modifier& mod) {
            return os << "\033[" << mod.code << "m";
        }
    };
}

Advanced

You may want to add additional features to the class. It is, for example, possible to add the color magenta and even styles like boldface. To do this, just an another entry to the Code enumeration. This is a good reference.

javascript : sending custom parameters with window.open() but its not working

You can use this but there remains a security issue

<script type="text/javascript">
function fnc1()
{
    var a=window.location.href;

    username="p";
    password=1234;
    window.open(a+'?username='+username+'&password='+password,"");

}   
</script>
<input type="button" onclick="fnc1()" />
<input type="text" id="atext"  />

jQuery - getting custom attribute from selected option

Try this:

$("#location").change(function(){
            var element = $("option:selected", this);
            var myTag = element.attr("myTag");

            $('#setMyTag').val(myTag);
        });

In the callback function for change(), this refers to the select, not to the selected option.

Where is Maven Installed on Ubuntu

Ubuntu 11.10 doesn't have maven3 in repo.

Follow below step to install maven3 on ubuntu 11.10

sudo add-apt-repository ppa:natecarlson/maven3
sudo apt-get update && sudo apt-get install maven3

Open terminal: mvn3 -v

if you want mvn as a binary then execute below script:

sudo ln -s /usr/bin/mvn3 /usr/bin/mvn

I hope this will help you.

Thanks, Rajam

How do I use select with date condition?

Select * from Users where RegistrationDate >= CONVERT(datetime, '01/20/2009', 103)

is safe to use, independent of the date settings on the server.

The full list of styles can be found here.

Redirecting from HTTP to HTTPS with PHP

On my AWS beanstalk server, I don't see $_SERVER['HTTPS'] variable. I do see $_SERVER['HTTP_X_FORWARDED_PROTO'] which can be either 'http' or 'https' so if you're hosting on AWS, use this:

if ($_SERVER['HTTP_HOST'] != 'localhost' and $_SERVER['HTTP_X_FORWARDED_PROTO'] != "https") {
    $location = 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
    header('HTTP/1.1 301 Moved Permanently');
    header('Location: ' . $location);
    exit;
}

Get all rows from SQLite

Cursor cursor = myDb.viewData();

        if (cursor.moveToFirst()){
              do {
                 String itemname=cursor.getString(cursor.getColumnIndex(myDb.col_2));
                 String price=cursor.getString(cursor.getColumnIndex(myDb.col_3));
                 String quantity=cursor.getString(cursor.getColumnIndex(myDb.col_4));
                 String table_no=cursor.getString(cursor.getColumnIndex(myDb.col_5));

                 }while (cursor.moveToNext());

                }

                cursor.requery();

jQuery select option elements by value

options = $("#span_id>select>option[value='"+i+"']");
option = options.text();
alert(option); 

here is the fiddle http://jsfiddle.net/hRFYF/

Escaping HTML strings with jQuery

I realize how late I am to this party, but I have a very easy solution that does not require jQuery.

escaped = new Option(unescaped).innerHTML;

Edit: This does not escape quotes. The only case where quotes would need to be escaped is if the content is going to be pasted inline to an attribute within an HTML string. It is hard for me to imagine a case where doing this would be good design.

Edit 3: For the fastest solution, check the answer above from Saram. This one is the shortest.

Why are hexadecimal numbers prefixed with 0x?

It's a prefix to indicate the number is in hexadecimal rather than in some other base. The C programming language uses it to tell compiler.

Example:

0x6400 translates to 6*16^3 + 4*16^2 + 0*16^1 +0*16^0 = 25600. When compiler reads 0x6400, It understands the number is hexadecimal with the help of 0x term. Usually we can understand by (6400)16 or (6400)8 or whatever ..

For binary it would be:

0b00000001

Hope I have helped in some way.

Good day!

Create a string with n characters

Since Java 11 you can simply use String.repeat(count) to solve your problem.

Returns a string whose value is the concatenation of this string repeated count times.

If this string is empty or count is zero then the empty string is returned.

So instead of a loop your code would just look like this:

" ".repeat(length);

How to make --no-ri --no-rdoc the default for gem install?

# /home/{user}/.gemrc

---
:update_sources: true
:sources:
- http://gems.rubyforge.org/
- http://gems.github.com
:benchmark: false
:bulk_threshold: 1000
:backtrace: false
:verbose: true
gem: --no-ri --no-rdoc

http://webonrails.com/2008/12/03/skiping-installation-of-ri-and-rdoc-documentation-while-installing-gems/

Can I connect to SQL Server using Windows Authentication from Java EE webapp?

I do not think one can push the user credentials from the browser to the database (and does it makes sense ? I think not)

But if you want to use the credentials of the user running Tomcat to connect to SQL Server then you can use Microsoft's JDBC Driver. Just build your JDBC URL like this:

jdbc:sqlserver://localhost;integratedSecurity=true;

And copy the appropriate DLL to Tomcat's bin directory (sqljdbc_auth.dll provided with the driver)

MSDN > Connecting to SQL Server with the JDBC Driver > Building the Connection URL

How to get build time stamp from Jenkins build variables?

NOTE: This changed in Jenkins 1.597, Please see here for more info regarding the migration

You should be able to view all the global environment variables that are available during the build by navigating to https://<your-jenkins>/env-vars.html.

Replace https://<your-jenkins>/ with the URL you use to get to Jenkins webpage (for example, it could be http://localhost:8080/env-vars.html).

One of the environment variables is :

BUILD_ID
    The current build id, such as "2005-08-22_23-59-59" (YYYY-MM-DD_hh-mm-ss)

If you use jenkins editable email notification, you should be able to use ${ENV, var="BUILD_ID"} in the subject line of your email.

How to write a Python module/package?

Once you have defined your chosen commands, you can simply drag and drop the saved file into the Lib folder in your python program files.

>>> import mymodule 
>>> mymodule.myfunc()

Change working directory in my current shell context when running Node script

Short answer: no (easy?) way, but you can do something that serves your purpose.

I've done a similar tool (a small command that, given a description of a project, sets environment, paths, directories, etc.). What I do is set-up everything and then spawn a shell with:

spawn('bash', ['-i'], {
  cwd: new_cwd,
  env: new_env,
  stdio: 'inherit'
});

After execution, you'll be on a shell with the new directory (and, in my case, environment). Of course you can change bash for whatever shell you prefer. The main differences with what you originally asked for are:

  • There is an additional process, so...
  • you have to write 'exit' to come back, and then...
  • after existing, all changes are undone.

However, for me, that differences are desirable.

For-loop vs while loop in R

Because 1 is numeric, but not integer (i.e. it's a floating point number), and 1:6000 is numeric and integer.

> print(class(1))
[1] "numeric"
> print(class(1:60000))
[1] "integer"

60000 squared is 3.6 billion, which is NOT representable in signed 32-bit integer, hence you get an overflow error:

> as.integer(60000)*as.integer(60000)
[1] NA
Warning message:
In as.integer(60000) * as.integer(60000) : NAs produced by integer overflow

3.6 billion is easily representable in floating point, however:

> as.single(60000)*as.single(60000)
[1] 3.6e+09

To fix your for code, convert to a floating point representation:

function (N)
{
    for(i in as.single(1:N)) {
        y <- i*i
    }
}

What are the differences between the urllib, urllib2, urllib3 and requests module?

I like the urllib.urlencode function, and it doesn't appear to exist in urllib2.

>>> urllib.urlencode({'abc':'d f', 'def': '-!2'})
'abc=d+f&def=-%212'

What is the height of Navigation Bar in iOS 7?

I got this answer from the book Programming iOS 7, section Bar Position and Bar Metrics

If a navigation bar or toolbar — or a search bar (discussed earlier in this chapter) — is to occupy the top of the screen, the iOS 7 convention is that its height should be increased to underlap the transparent status bar. To make this possible, iOS 7 introduces the notion of a bar position.

UIBarPositionTopAttached

Specifies that the bar is at the top of the screen, as well as its containing view. Bars with this position draw their background extended upwards, allowing their background content to show through the status bar. Available in iOS 7.0 and later.

React-Native Button style not work

I had an issue with margin and padding with a Button. I added Button inside a View component and apply your properties to the View.

<View style={{margin:10}}>
<Button
  title="Decrypt Data"
  color="orange"
  accessibilityLabel="Tap to Decrypt Data"
  onPress={() => {
    Alert.alert('You tapped the Decrypt button!');
  }}
  />  
</View>

Integrating CSS star rating into an HTML form

This is very easy to use, just copy-paste the code. You can use your own star image in background.

I have created a variable var userRating. you can use this variable to get value from stars.

Enjoy!! :)

_x000D_
_x000D_
$(document).ready(function(){_x000D_
    // Check Radio-box_x000D_
    $(".rating input:radio").attr("checked", false);_x000D_
_x000D_
    $('.rating input').click(function () {_x000D_
        $(".rating span").removeClass('checked');_x000D_
        $(this).parent().addClass('checked');_x000D_
    });_x000D_
_x000D_
    $('input:radio').change(_x000D_
      function(){_x000D_
        var userRating = this.value;_x000D_
        alert(userRating);_x000D_
    }); _x000D_
});
_x000D_
.rating {_x000D_
    float:left;_x000D_
    width:300px;_x000D_
}_x000D_
.rating span { float:right; position:relative; }_x000D_
.rating span input {_x000D_
    position:absolute;_x000D_
    top:0px;_x000D_
    left:0px;_x000D_
    opacity:0;_x000D_
}_x000D_
.rating span label {_x000D_
    display:inline-block;_x000D_
    width:30px;_x000D_
    height:30px;_x000D_
    text-align:center;_x000D_
    color:#FFF;_x000D_
    background:#ccc;_x000D_
    font-size:30px;_x000D_
    margin-right:2px;_x000D_
    line-height:30px;_x000D_
    border-radius:50%;_x000D_
    -webkit-border-radius:50%;_x000D_
}_x000D_
.rating span:hover ~ span label,_x000D_
.rating span:hover label,_x000D_
.rating span.checked label,_x000D_
.rating span.checked ~ span label {_x000D_
    background:#F90;_x000D_
    color:#FFF;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="rating">_x000D_
    <span><input type="radio" name="rating" id="str5" value="5"><label for="str5"></label></span>_x000D_
    <span><input type="radio" name="rating" id="str4" value="4"><label for="str4"></label></span>_x000D_
    <span><input type="radio" name="rating" id="str3" value="3"><label for="str3"></label></span>_x000D_
    <span><input type="radio" name="rating" id="str2" value="2"><label for="str2"></label></span>_x000D_
    <span><input type="radio" name="rating" id="str1" value="1"><label for="str1"></label></span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Find empty or NaN entry in Pandas Dataframe

Check if the columns contain Nan using .isnull() and check for empty strings using .eq(''), then join the two together using the bitwise OR operator |.

Sum along axis 0 to find columns with missing data, then sum along axis 1 to the index locations for rows with missing data.

missing_cols, missing_rows = (
    (df2.isnull().sum(x) | df2.eq('').sum(x))
    .loc[lambda x: x.gt(0)].index
    for x in (0, 1)
)

>>> df2.loc[missing_rows, missing_cols]
         A2       A3
2            1.10035
5 -0.508501         
6       NaN      NaN
7       NaN      NaN

SQLAlchemy IN clause

Just an addition to the answers above.

If you want to execute a SQL with an "IN" statement you could do this:

ids_list = [1,2,3]
query = "SELECT id, name FROM user WHERE id IN %s" 
args = [(ids_list,)] # Don't forget the "comma", to force the tuple
conn.execute(query, args)

Two points:

  • There is no need for Parenthesis for the IN statement(like "... IN(%s) "), just put "...IN %s"
  • Force the list of your ids to be one element of a tuple. Don't forget the " , " : (ids_list,)

EDIT Watch out that if the length of list is one or zero this will raise an error!

omp parallel vs. omp parallel for

There are obviously plenty of answers, but this one answers it very nicely (with source)

#pragma omp for only delegates portions of the loop for different threads in the current team. A team is the group of threads executing the program. At program start, the team consists only of a single member: the master thread that runs the program.

To create a new team of threads, you need to specify the parallel keyword. It can be specified in the surrounding context:

#pragma omp parallel
{
   #pragma omp for
   for(int n = 0; n < 10; ++n)
   printf(" %d", n);
}

and:

What are: parallel, for and a team

The difference between parallel, parallel for and for is as follows:

A team is the group of threads that execute currently. At the program beginning, the team consists of a single thread. A parallel construct splits the current thread into a new team of threads for the duration of the next block/statement, after which the team merges back into one. for divides the work of the for-loop among the threads of the current team.

It does not create threads, it only divides the work amongst the threads of the currently executing team. parallel for is a shorthand for two commands at once: parallel and for. Parallel creates a new team, and for splits that team to handle different portions of the loop. If your program never contains a parallel construct, there is never more than one thread; the master thread that starts the program and runs it, as in non-threading programs.

https://bisqwit.iki.fi/story/howto/openmp/

How do I put the image on the right side of the text in a UIButton?

Took @Piotr's answer and made it into a Swift extension. Make sure to set the image and title before calling this, so that the button sizes properly.

 extension UIButton {
    
    /// Makes the ``imageView`` appear just to the right of the ``titleLabel``.
    func alignImageRight() {
        if let titleLabel = self.titleLabel, imageView = self.imageView {
            // Force the label and image to resize.
            titleLabel.sizeToFit()
            imageView.sizeToFit()
            imageView.contentMode = .ScaleAspectFit
            
            // Set the insets so that the title appears to the left and the image appears to the right. 
            // Make the image appear slightly off the top/bottom edges of the button.
            self.titleEdgeInsets = UIEdgeInsets(top: 0, left: -1 * imageView.frame.size.width,
                bottom: 0, right: imageView.frame.size.width)
            self.imageEdgeInsets = UIEdgeInsets(top: 4, left: titleLabel.frame.size.width,
                bottom: 4, right: -1 * titleLabel.frame.size.width)
          }
        }
     }

How do I convert a file path to a URL in ASP.NET

The simple solution seems to be to have a temporary location within the website that you can access easily with URL and then you can move files to the physical location when you need to save them.

Java Timestamp - How can I create a Timestamp with the date 23/09/2007?

You could also do the following:

// untested
Calendar cal = GregorianCalendar.getInstance();
cal.set(Calendar.DAY_OF_MONTH, 23);// I might have the wrong Calendar constant...
cal.set(Calendar.MONTH, 8);// -1 as month is zero-based
cal.set(Calendar.YEAR, 2009);
Timestamp tstamp = new Timestamp(cal.getTimeInMillis());

In Python, what happens when you import inside of a function?

It imports once when the function executes first time.

Pros:

  • imports related to the function they're used in
  • easy to move functions around the package

Cons:

  • couldn't see what modules this module might depend on

How to change a nullable column to not nullable in a Rails migration?

In Rails 4.02+ according to the docs there is no method like update_all with 2 arguments. Instead one can use this code:

# Make sure no null value exist
MyModel.where(date_column: nil).update_all(date_column: Time.now)

# Change the column to not allow null
change_column :my_models, :date_column, :datetime, null: false

Android translate animation - permanently move View to new position using AnimationListener

Just Do like this

view.animate()
            .translationY(-((root.height - (view.height)) / 2).toFloat())
            .setInterpolator(AccelerateInterpolator()).duration = 1500

Here, view is your View which is animating from its origin position. root is root View of your XML file.

Calculation inside translationY is made for moving your view to the top but keeping it inside the screen, otherwise, it will go partially outside of the screen if you keep its value 0.

jQuery Screen Resolution Height Adjustment

Here is an example on how to center an object vertically with jQuery:

var div= $('#div_SomeDivYouWantToAdjust');
div.css("top", ($(window).height() - div.height())/2  + 'px');

But you could easily change that to whatever your needs are.

Quoting backslashes in Python string literals

Use a raw string:

>>> foo = r'baz "\"'
>>> foo
'baz "\\"'

Note that although it looks wrong, it's actually right. There is only one backslash in the string foo.

This happens because when you just type foo at the prompt, python displays the result of __repr__() on the string. This leads to the following (notice only one backslash and no quotes around the printed string):

>>> foo = r'baz "\"'
>>> foo
'baz "\\"'
>>> print(foo)
baz "\"

And let's keep going because there's more backslash tricks. If you want to have a backslash at the end of the string and use the method above you'll come across a problem:

>>> foo = r'baz \'
  File "<stdin>", line 1
    foo = r'baz \'
                 ^  
SyntaxError: EOL while scanning single-quoted string

Raw strings don't work properly when you do that. You have to use a regular string and escape your backslashes:

>>> foo = 'baz \\'
>>> print(foo)
baz \

However, if you're working with Windows file names, you're in for some pain. What you want to do is use forward slashes and the os.path.normpath() function:

myfile = os.path.normpath('c:/folder/subfolder/file.txt')
open(myfile)

This will save a lot of escaping and hair-tearing. This page was handy when going through this a while ago.

How do I remove the non-numeric character from a string in java?

String str= "somestring";
String[] values = str.split("\\D+"); 

How to get CPU temperature?

I extracted the CPU part from Open Hardware Monitor into a separated library, exposing sensors and members normally hidden into OHM. It also includes many updates (like the support for Ryzen and Xeon) because on OHM they don't accept pull requests since 2015.

https://www.nuget.org/packages/HardwareProviders.CPU.Standard/

Let know your opinion :)

How to convert a string to an integer in JavaScript?

I only added one plus(+) before string and that was solution!

+"052254" //52254

Hope it helps ;)

Bash conditionals: how to "and" expressions? (if [ ! -z $VAR && -e $VAR ])

I found an answer now. Thanks for your suggestions!

for e in ./*.cutoff.txt; do
if grep -q -E 'COX1|Cu-oxidase' $e
then
    echo xyz >$e.match.txt
else
    echo
fi

if grep -q -E 'AMO' $e
then
    echo abc >$e.match.txt
else
    echo
fi; done

Any comments on that? It seems inefficient to grep twice, but it works...

How to clear the entire array?

ReDim aFirstArray(0)

This will resize the array to zero and erase all data.

Bash script processing limited number of commands in parallel

Use the wait built-in:

process1 &
process2 &
process3 &
process4 &
wait
process5 &
process6 &
process7 &
process8 &
wait

For the above example, 4 processes process1 ... process4 would be started in the background, and the shell would wait until those are completed before starting the next set.

From the GNU manual:

wait [jobspec or pid ...]

Wait until the child process specified by each process ID pid or job specification jobspec exits and return the exit status of the last command waited for. If a job spec is given, all processes in the job are waited for. If no arguments are given, all currently active child processes are waited for, and the return status is zero. If neither jobspec nor pid specifies an active child process of the shell, the return status is 127.

How to get progress from XMLHttpRequest

One of the most promising approaches seems to be opening a second communication channel back to the server to ask it how much of the transfer has been completed.

Create normal zip file programmatically

This can be done by adding a reference to System.IO.Compression and System.IO.Compression.Filesystem.

A sample createZipFile() method may look as following:

public static void createZipFile(string inputfile, string outputfile, CompressionLevel compressionlevel)
        {
            try
            {
                using (ZipArchive za = ZipFile.Open(outputfile, ZipArchiveMode.Update))
                {
                    //using the same file name as entry name
                    za.CreateEntryFromFile(inputfile, inputfile);
                }
            }
            catch (ArgumentException)
            {
                Console.WriteLine("Invalid input/output file.");
                Environment.Exit(-1);
            }
}

where

  • inputfile= string with the file name to be compressed (for this example, you have to add the extension)
  • outputfile= string with the destination zip file name

More details about ZipFile Class in MSDN

Breaking out of a for loop in Java

How about

for (int k = 0; k < 10; k = k + 2) {
    if (k == 2) {
        break;
    }

    System.out.println(k);
}

The other way is a labelled loop

myloop:  for (int i=0; i < 5; i++) {

              for (int j=0; j < 5; j++) {

                if (i * j > 6) {
                  System.out.println("Breaking");
                  break myloop;
                }

                System.out.println(i + " " + j);
              }
          }

For an even better explanation you can check here

The type or namespace name could not be found

Other problem that might be causing such behavior are build configurations.

I had two projects with configurations set to be built to specific folders. Like Debug and Any CPU and in second it was Debug and x86.

What I did I went to Solution->Context menu->Properties->Configuration properties->Configuration and I set all my projects to use same configurations Debug and x86 and also checked Build tick mark.

Then projects started to build correctly and were able to see namespaces.

Get the first item from an iterable that matches a condition

Oneliner:

thefirst = [i for i in range(10) if i > 3][0]

If youre not sure that any element will be valid according to the criteria, you should enclose this with try/except since that [0] can raise an IndexError.

How do I tell Matplotlib to create a second (new) plot, then later plot on the old one?

One way I found after some struggling is creating a function which gets data_plot matrix, file name and order as parameter to create boxplots from the given data in the ordered figure (different orders = different figures) and save it under the given file_name.

def plotFigure(data_plot,file_name,order):
    fig = plt.figure(order, figsize=(9, 6))
    ax = fig.add_subplot(111)
    bp = ax.boxplot(data_plot)
    fig.savefig(file_name, bbox_inches='tight')
    plt.close()

Get an element by index in jQuery

You can use jQuery's .eq() method to get the element with a certain index.

$('ul li').eq(index).css({'background-color':'#343434'});

PHP "php://input" vs $_POST

If post data is malformed, $_POST will not contain anything. Yet, php://input will have the malformed string.

For example there is some ajax applications, that do not form correct post key-value sequence for uploading a file, and just dump all the file as post data, without variable names or anything. $_POST will be empty, $_FILES empty also, and php://input will contain exact file, written as a string.

How to count the occurrence of certain item in an ndarray?

No one suggested to use numpy.bincount(input, minlength) with minlength = np.size(input), but it seems to be a good solution, and definitely the fastest:

In [1]: choices = np.random.randint(0, 100, 10000)

In [2]: %timeit [ np.sum(choices == k) for k in range(min(choices), max(choices)+1) ]
100 loops, best of 3: 2.67 ms per loop

In [3]: %timeit np.unique(choices, return_counts=True)
1000 loops, best of 3: 388 µs per loop

In [4]: %timeit np.bincount(choices, minlength=np.size(choices))
100000 loops, best of 3: 16.3 µs per loop

That's a crazy speedup between numpy.unique(x, return_counts=True) and numpy.bincount(x, minlength=np.max(x)) !

link_to image tag. how to add class to a tag

Hey guys this is a good way of link w/ image and has lot of props in case you want to css attribute for example replace "alt" or "title" etc.....also including a logical restriction (?)

<%= link_to image_tag("#{request.ssl? ? @image_domain_secure : @image_domain}/images/linkImage.png", {:alt=>"Alt title", :title=>"Link title"}) , "http://www.site.com"%>

Hope this helps!

Populate data table from data reader

I looked into this as well, and after comparing the SqlDataAdapter.Fill method with the SqlDataReader.Load funcitons, I've found that the SqlDataAdapter.Fill method is more than twice as fast with the result sets I've been using

Used code:

    [TestMethod]
    public void SQLCommandVsAddaptor()
    {
        long AdapterFillLargeTableTime, readerLoadLargeTableTime, AdapterFillMediumTableTime, readerLoadMediumTableTime, AdapterFillSmallTableTime, readerLoadSmallTableTime, AdapterFillTinyTableTime, readerLoadTinyTableTime;

        string LargeTableToFill = "select top 10000 * from FooBar";
        string MediumTableToFill = "select top 1000 * from FooBar";
        string SmallTableToFill = "select top 100 * from FooBar";
        string TinyTableToFill = "select top 10 * from FooBar";

        using (SqlConnection sconn = new SqlConnection("Data Source=.;initial catalog=Foo;persist security info=True; user id=bar;password=foobar;"))
        {
            // large data set measurements
            AdapterFillLargeTableTime = MeasureExecutionTimeMethod(sconn, LargeTableToFill, ExecuteDataAdapterFillStep);
            readerLoadLargeTableTime = MeasureExecutionTimeMethod(sconn, LargeTableToFill, ExecuteSqlReaderLoadStep);
            // medium data set measurements
            AdapterFillMediumTableTime = MeasureExecutionTimeMethod(sconn, MediumTableToFill, ExecuteDataAdapterFillStep);
            readerLoadMediumTableTime = MeasureExecutionTimeMethod(sconn, MediumTableToFill, ExecuteSqlReaderLoadStep);
            // small data set measurements
            AdapterFillSmallTableTime = MeasureExecutionTimeMethod(sconn, SmallTableToFill, ExecuteDataAdapterFillStep);
            readerLoadSmallTableTime = MeasureExecutionTimeMethod(sconn, SmallTableToFill, ExecuteSqlReaderLoadStep);
            // tiny data set measurements
            AdapterFillTinyTableTime = MeasureExecutionTimeMethod(sconn, TinyTableToFill, ExecuteDataAdapterFillStep);
            readerLoadTinyTableTime = MeasureExecutionTimeMethod(sconn, TinyTableToFill, ExecuteSqlReaderLoadStep);
        }
        using (StreamWriter writer = new StreamWriter("result_sql_compare.txt"))
        {
            writer.WriteLine("10000 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 10000 rows: {0} milliseconds", AdapterFillLargeTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 10000 rows: {0} milliseconds", readerLoadLargeTableTime);
            writer.WriteLine("1000 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 1000 rows: {0} milliseconds", AdapterFillMediumTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 1000 rows: {0} milliseconds", readerLoadMediumTableTime);
            writer.WriteLine("100 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 100 rows: {0} milliseconds", AdapterFillSmallTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 100 rows: {0} milliseconds", readerLoadSmallTableTime);
            writer.WriteLine("10 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 10 rows: {0} milliseconds", AdapterFillTinyTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 10 rows: {0} milliseconds", readerLoadTinyTableTime);

        }
        Process.Start("result_sql_compare.txt");
    }

    private long MeasureExecutionTimeMethod(SqlConnection conn, string query, Action<SqlConnection, string> Method)
    {
        long time; // know C#
        // execute single read step outside measurement time, to warm up cache or whatever
        Method(conn, query);
        // start timing
        time = Environment.TickCount;
        for (int i = 0; i < 100; i++)
        {
            Method(conn, query);
        }
        // return time in milliseconds
        return Environment.TickCount - time;
    }

    private void ExecuteDataAdapterFillStep(SqlConnection conn, string query)
    {
        DataTable tab = new DataTable();
        conn.Open();
        using (SqlDataAdapter comm = new SqlDataAdapter(query, conn))
        {
            // Adapter fill table function
            comm.Fill(tab);
        }
        conn.Close();
    }

    private void ExecuteSqlReaderLoadStep(SqlConnection conn, string query)
    {
        DataTable tab = new DataTable();
        conn.Open();
        using (SqlCommand comm = new SqlCommand(query, conn))
        {
            using (SqlDataReader reader = comm.ExecuteReader())
            {
                // IDataReader Load function
                tab.Load(reader);
            }
        }
        conn.Close();
    }

Results:

10000 rows:
Sql Data Adapter 100 times table fill speed 10000 rows: 11782 milliseconds
Sql Data Reader  100 times table load speed 10000 rows: 26047 milliseconds
1000 rows:
Sql Data Adapter 100 times table fill speed 1000 rows: 984  milliseconds
Sql Data Reader  100 times table load speed 1000 rows: 2031 milliseconds
100 rows:
Sql Data Adapter 100 times table fill speed 100 rows: 125 milliseconds
Sql Data Reader  100 times table load speed 100 rows: 235 milliseconds
10 rows:
Sql Data Adapter 100 times table fill speed 10 rows: 32 milliseconds
Sql Data Reader  100 times table load speed 10 rows: 93 milliseconds

For performance issues, using the SqlDataAdapter.Fill method is far more efficient. So unless you want to shoot yourself in the foot use that. It works faster for small and large data sets.

Undo git update-index --assume-unchanged <file>

git update-index function has several option you can find typing as below:

git update-index --help

Here you will find various option - how to handle with the function update-index.

[if you don't know the file name]

git update-index --really-refresh 

[if you know the file name ]

git update-index --no-assume-unchanged <file>

will revert all the files those have been added in ignore list through.

git update-index --assume-unchanged <file>

What does the "~" (tilde/squiggle/twiddle) CSS selector mean?

The ~ selector is in fact the General sibling combinator (renamed to Subsequent-sibling combinator in selectors Level 4):

The general sibling combinator is made of the "tilde" (U+007E, ~) character that separates two sequences of simple selectors. The elements represented by the two sequences share the same parent in the document tree and the element represented by the first sequence precedes (not necessarily immediately) the element represented by the second one.

Consider the following example:

_x000D_
_x000D_
.a ~ .b {_x000D_
  background-color: powderblue;_x000D_
}
_x000D_
<ul>_x000D_
  <li class="b">1st</li>_x000D_
  <li class="a">2nd</li>_x000D_
  <li>3rd</li>_x000D_
  <li class="b">4th</li>_x000D_
  <li class="b">5th</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

.a ~ .b matches the 4th and 5th list item because they:

  • Are .b elements
  • Are siblings of .a
  • Appear after .a in HTML source order.

Likewise, .check:checked ~ .content matches all .content elements that are siblings of .check:checked and appear after it.

get current date from [NSDate date] but set the time to 10:00 am

NSDate *currentDate = [NSDate date];
NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setHour:10];
NSDate *date = [gregorian dateByAddingComponents:comps toDate:currentDate  options:0];
[comps release];

Not tested in xcode though :)

What is the simplest way to swap each pair of adjoining chars in a string with Python?

Do you want the digits sorted? Or are you swapping odd/even indexed digits? Your example is totally unclear.

Sort:

s = '2143'
p=list(s)
p.sort()
s = "".join(p)

s is now '1234'. The trick is here that list(string) breaks it into characters.

Implement touch using Python?

Looks like this is new as of Python 3.4 - pathlib.

from pathlib import Path

Path('path/to/file.txt').touch()

This will create a file.txt at the path.

--

Path.touch(mode=0o777, exist_ok=True)

Create a file at this given path. If mode is given, it is combined with the process’ umask value to determine the file mode and access flags. If the file already exists, the function succeeds if exist_ok is true (and its modification time is updated to the current time), otherwise FileExistsError is raised.

Getting parts of a URL (Regex)

A single regex to parse and breakup a full URL including query parameters and anchors e.g.

https://www.google.com/dir/1/2/search.html?arg=0-a&arg1=1-b&arg3-c#hash

^((http[s]?|ftp):\/)?\/?([^:\/\s]+)((\/\w+)*\/)([\w\-\.]+[^#?\s]+)(.*)?(#[\w\-]+)?$

RexEx positions:

url: RegExp['$&'],

protocol:RegExp.$2,

host:RegExp.$3,

path:RegExp.$4,

file:RegExp.$6,

query:RegExp.$7,

hash:RegExp.$8

you could then further parse the host ('.' delimited) quite easily.

What I would do is use something like this:

/*
    ^(.*:)//([A-Za-z0-9\-\.]+)(:[0-9]+)?(.*)$
*/
proto $1
host $2
port $3
the-rest $4

the further parse 'the rest' to be as specific as possible. Doing it in one regex is, well, a bit crazy.

Angular - Use pipes in services and components

As of Angular 6 you can import formatDate from @angular/common utility to use inside the components.

It was intruduced at https://github.com/smdunn/angular/commit/3adeb0d96344c15201f7f1a0fae7e533a408e4ae

I can be used as:

import {formatDate} from '@angular/common';
formatDate(new Date(), 'd MMM yy HH:mm', 'en');

Although the locale has to be supplied

Find files and tar them (with spaces)

The best solution seem to be to create a file list and then archive files because you can use other sources and do something else with the list.

For example this allows using the list to calculate size of the files being archived:

#!/bin/sh

backupFileName="backup-big-$(date +"%Y%m%d-%H%M")"
backupRoot="/var/www"
backupOutPath=""

archivePath=$backupOutPath$backupFileName.tar.gz
listOfFilesPath=$backupOutPath$backupFileName.filelist

#
# Make a list of files/directories to archive
#
echo "" > $listOfFilesPath
echo "${backupRoot}/uploads" >> $listOfFilesPath
echo "${backupRoot}/extra/user/data" >> $listOfFilesPath
find "${backupRoot}/drupal_root/sites/" -name "files" -type d >> $listOfFilesPath

#
# Size calculation
#
sizeForProgress=`
cat $listOfFilesPath | while read nextFile;do
    if [ ! -z "$nextFile" ]; then
        du -sb "$nextFile"
    fi
done | awk '{size+=$1} END {print size}'
`

#
# Archive with progress
#
## simple with dump of all files currently archived
#tar -czvf $archivePath -T $listOfFilesPath
## progress bar
sizeForShow=$(($sizeForProgress/1024/1024))
echo -e "\nRunning backup [source files are $sizeForShow MiB]\n"
tar -cPp -T $listOfFilesPath | pv -s $sizeForProgress | gzip > $archivePath

Horizontal line using HTML/CSS

I have try this my new code and it might be helpful to you, it works perfectly in google chromr

hr {
     color: #f00;
     background: #f00; 
     width: 75%; 
     height: 5px;
}

C++ class forward declaration

The forward declaration is an "incomplete type", the only thing you can do with such a type is instantiate a pointer to it, or reference it in a function declaration (i.e. and argument or return type in a function prototype). In line 52 in your code, you are attempting to instantiate an object.

At that point the compiler has no knowledge of the object's size nor its constructor, so cannot instantiate an object.

UILabel Align Text to center

In Swift 4.2 and Xcode 10

let lbl = UILabel(frame: CGRect(x: 10, y: 50, width: 230, height: 21))
lbl.textAlignment = .center //For center alignment
lbl.text = "This is my label fdsjhfg sjdg dfgdfgdfjgdjfhg jdfjgdfgdf end..."
lbl.textColor = .white
lbl.backgroundColor = .lightGray//If required
lbl.font = UIFont.systemFont(ofSize: 17)

 //To display multiple lines in label
lbl.numberOfLines = 0
lbl.lineBreakMode = .byWordWrapping

lbl.sizeToFit()//If required
yourView.addSubview(lbl)

Is `shouldOverrideUrlLoading` really deprecated? What can I use instead?

Implement both deprecated and non-deprecated methods like below. First one is to handle API level 21 and higher, second one is handle lower than API level 21

webViewClient = object : WebViewClient() {
.
.
        @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
        override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {
            parseUri(request?.url)
            return true
        }

        @SuppressWarnings("deprecation")
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
            parseUri(Uri.parse(url))
            return true
        }
}

Closing Application with Exit button

this.close_Button = (Button)this.findViewById(R.id.close);
   this.close_Button.setOnClickListener(new OnClickListener() {
     @Override
     public void onClick(View v) {
        finish();
     }
  });

finish() - Call this when your activity is done and should be closed. The ActivityResult is propagated back to whoever launched you via onActivityResult().

What is the difference between DSA and RSA?

And in addition to the above nice answers.

  • DSA uses Discrete logarithm.
  • RSA uses Integer Factorization.

RSA stands for Ron Rivest, Adi Shamir and Leonard Adleman.

How can I control the speed that bootstrap carousel slides in items?

In your CSS:

.carousel-item {
    transition-duration: 1.5s, 1.5s;
}

Take care, the time is included in data-interval defined for the carousel.

Hope it helps... :)

Send message to specific client with socket.io and node.js

You can use

//send message only to sender-client

socket.emit('message', 'check this');

//or you can send to all listeners including the sender

io.emit('message', 'check this');

//send to all listeners except the sender

socket.broadcast.emit('message', 'this is a message');

//or you can send it to a room

socket.broadcast.to('chatroom').emit('message', 'this is the message to all');

How to parse date string to Date?

A parse exception is a checked exception, so you must catch it with a try-catch when working with parsing Strings to Dates, as @miku suggested...

tar: Error is not recoverable: exiting now

The problem is that you do not have bzip2 installed. The tar program relies upon this external program to do compression. For installing bzip2, it depends on the system you are using. For example, with Ubuntu that would be on Ubuntu

sudo apt-get install bzip2

The GNU tar program does not know how to compress an existing file such as user-logs.tar (bzip2 does that). The tar program can use external compression programs gzip, bzip2, xz by opening a pipe to those programs, sending a tar archive via the pipe to the compression utility, which compresses the data which it reads from tar and writes the result to the filename which the tar program specifies.

Alternatively, the tar and compression utility could be the same program. BSD tar does its compression using lib archive (they're not really distinct except in name).

Using <style> tags in the <body> with other HTML

In your example, a browser isn't "supposed" to do anything. The HTML is invalid. Either error recovery is triggered, or the parser makes of it as it will.

In a valid instance, multiple stylesheets are just treated as appearing one after the other, the cascade is calculated as normal.

Why do we use $rootScope.$broadcast in AngularJS?

Passing data !!!

I wonder why no one mention that $broadcast accept a parameter where you can pass an Object that will be received by $on using a callback function

Example:

// the object to transfert
var myObject = {
    status : 10
}

$rootScope.$broadcast('status_updated', myObject);
$scope.$on('status_updated', function(event, obj){
    console.log(obj.status); // 10
})

How to finish current activity in Android

Just call the finish() method:

context.finish();

Python read next()

Using next or readlines etc, is not necessary. As the documentation says: "For reading lines from a file, you can loop over the file object. This is memory efficient, fast, and leads to simple code".

Here's an example:

with open('/path/to/file') as myfile:
    for line in myfile:
        print(line)

How to use multiple databases in Laravel

Actually, DB::connection('name')->select(..) doesnt work for me, because 'name' has to be in double quotes: "name"

Still, the select query is executed on my default connection. Still trying to figure out, how to convince Laravel to work the way it is intended: change the connection.

Edit: I figured it out. After debugging Laravels DatabaseManager it turned out my database.php (config file) (inside $this->app) was wrong. In the section "connections" I had stuff like "database" with values of the one i copied it from. In clear terms, instead of

env('DB_DATABASE', 'name')

I needed to place something like

'myNewName'

since all connections were listed with the same values for the database, username, password, etc. which of course makes little sense if I want to access at least another database name

Therefore, every time I wanted to select something from another database I always ended up in my default database

What is the best way to know if all the variables in a Class are null?

I think this is a solution that solves your problem easily: (return true if any of the parameters is not null)

  public boolean isUserEmpty(){ 
boolean isEmpty;
isEmpty =  isEmpty = Stream.of(id,
            name)
        .anyMatch(userParameter -> userParameter != null);

return isEmpty;}

Another solution to the same task is:(you can change it to if(isEmpty==0) checks if all the parameters are null.

public boolean isUserEmpty(){  
       long isEmpty;
            isEmpty = Stream.of(id,
                    name)
                    .filter(userParameter -> userParameter != null).count();

            if (isEmpty > 0) {
                return true;
            } else {
                return false;
            }
    }

How can I declare enums using java

public enum NewEnum {
   ONE("test"),
   TWO("test");

   private String s;

   private NewEnum(String s) {
      this.s = s);
   }

    public String getS() {
        return this.s;
    }
}

Wrapping a react-router Link in an html button

Update for React Router version 6:

The various answers here are like a timeline of react-router's evolution

Using the latest hooks from react-router v6, this can now be done easily with the useNavigate hook.

import { useNavigate } from 'react-router-dom'      

function MyLinkButton() {
  const navigate = useNavigate()
  return (
      <button onClick={() => navigate("/home")}>
        Go Home
      </button>
  );
}

MessageBox Buttons?

if(DialogResult.OK==MessageBox.Show("Do you Agree with me???"))
{
         //do stuff if yess
}
else
{
         //do stuff if No
}

Remove last commit from remote git repository

Be careful that this will create an "alternate reality" for people who have already fetch/pulled/cloned from the remote repository. But in fact, it's quite simple:

git reset HEAD^ # remove commit locally
git push origin +HEAD # force-push the new HEAD commit

If you want to still have it in your local repository and only remove it from the remote, then you can use:

git push origin +HEAD^:<name of your branch, most likely 'master'>

Getting list of tables, and fields in each, in a database

This will get you all the user created tables:

select * from sysobjects where xtype='U'

To get the cols:

Select * from Information_Schema.Columns Where Table_Name = 'Insert Table Name Here'

Also, I find http://www.sqlservercentral.com/ to be a pretty good db resource.

Installation of VB6 on Windows 7 / 8 / 10

I've installed and use VB6 for legacy projects many times on Windows 7.

What I have done and never came across any issues, is to install VB6, ignore the errors and then proceed to install the latest service pack, currently SP6.

Download here: http://www.microsoft.com/en-us/download/details.aspx?id=5721

Bonus: Also once you install it and realize that scrolling doesn't work, use the below: http://www.joebott.com/vb6scrollwheel.htm

Anyway to prevent the Blue highlighting of elements in Chrome when clicking quickly?

This works the best for me:

.noSelect:hover {
  background-color: white;
}

laravel select where and where condition

After rigorous testing, I found out that the source of my problem is Hash::make('password'). Apparently this kept generating a different hash each time. SO I replaced this with my own hashing function (wrote previously in codeigniter) and viola! things worked well.

Thanks again for helping out :) Really appreciate it!

How to convert a string to a date in sybase

Use the convert function, for example:

select * from data 
where dateVal < convert(datetime, '01/01/2008', 103)

Where the convert style (103) determines the date format to use.

Spark specify multiple column conditions for dataframe join

There is a Spark column/expression API join for such case:

Leaddetails.join(
    Utm_Master, 
    Leaddetails("LeadSource") <=> Utm_Master("LeadSource")
        && Leaddetails("Utm_Source") <=> Utm_Master("Utm_Source")
        && Leaddetails("Utm_Medium") <=> Utm_Master("Utm_Medium")
        && Leaddetails("Utm_Campaign") <=> Utm_Master("Utm_Campaign"),
    "left"
)

The <=> operator in the example means "Equality test that is safe for null values".

The main difference with simple Equality test (===) is that the first one is safe to use in case one of the columns may have null values.

How to get 'System.Web.Http, Version=5.2.3.0?

Install-Package Microsoft.AspNet.WebApi.Core -version 5.2.3

Then in the project Add Reference -> Browse. Push the browse button and go to the C:\Users\UserName\Documents\Visual Studio 2015\Projects\ProjectName\packages\Microsoft.AspNet.Mvc.5.2.3\lib\net45 and add the needed .dll file

Is there a naming convention for MySQL?

as @fabrizio-valencia said use lower case. in windows if you export mysql database (phpmyadmin) the tables name will converted to lower case and this lead to all sort of problems. see Are table names in MySQL case sensitive?

Reactjs - setting inline styles correctly

You need to do this:

var scope = {
     splitterStyle: {
         height: 100
     }
};

And then apply this styling to the required elements:

<div id="horizontal" style={splitterStyle}>

In your code you are doing this (which is incorrect):

<div id="horizontal" style={height}>

Where height = 100.

access denied for user @ 'localhost' to database ''

Try this: Adding users to MySQL

You need grant privileges to the user if you want external acess to database(ie. web pages).

switch() statement usage

In short, yes. But there are times when you might favor one vs. the other. Google "case switch vs. if else". There are some discussions already on SO too. Also, here is a good video that talks about it in the context of MATLAB:

http://blogs.mathworks.com/pick/2008/01/02/matlab-basics-switch-case-vs-if-elseif/

Personally, when I have 3 or more cases, I usually just go with case/switch.

How to set css style to asp.net button?

I Found the coding...

 input[type="submit"]
    {
     //css coding
    }
 input[type="submit"]:Hover  
    {
     //css coding
    }

This is the solution for my issue..... Thanks everyone for the valuable answers.......

Difference between <input type='button' /> and <input type='submit' />

IE 8 actually uses the first button it encounters submit or button. Instead of easily indicating which is desired by making it a input type=submit the order on the page is actually significant.

How to do SVN Update on my project using the command line

From the command line it would be just:

svn update

(in the directory you've got a copy of a SVN project).

Error System.Data.OracleClient requires Oracle client software version 8.1.7 or greater when installs setup

After installation of Oracle Client 11.02.04, reboot the server and make sure USERS(Local Computer) is added with Full Control on Root folder for eg WWW

Tested, it worked.

Example to use shared_ptr?

#include <memory>
#include <iostream>

class SharedMemory {
    public: 
        SharedMemory(int* x):_capture(x){}
        int* get() { return (_capture.get()); }
    protected:
        std::shared_ptr<int> _capture;
};

int main(int , char**){
    SharedMemory *_obj1= new SharedMemory(new int(10));
    SharedMemory *_obj2 = new SharedMemory(*_obj1);
    std::cout << " _obj1: " << *_obj1->get() << " _obj2: " << *_obj2->get()
    << std::endl;
    delete _obj2;

    std::cout << " _obj1: " << *_obj1->get() << std::endl;
    delete _obj1;
    std::cout << " done " << std::endl;
}

This is an example of shared_ptr in action. _obj2 was deleted but pointer is still valid. output is, ./test _obj1: 10 _obj2: 10 _obj2: 10 done

The default for KeyValuePair

Try this:

KeyValuePair<string,int> current = this.recent.SingleOrDefault(r => r.Key.Equals(dialog.FileName) == true);

if (current.Key == null)
    this.recent.Add(new KeyValuePair<string,int>(dialog.FileName,0));

AngularJS - Passing data between pages

You need to create a service to be able to share data between controllers.

app.factory('myService', function() {
 var savedData = {}
 function set(data) {
   savedData = data;
 }
 function get() {
  return savedData;
 }

 return {
  set: set,
  get: get
 }

});

In your controller A:

myService.set(yourSharedData);

In your controller B:

$scope.desiredLocation = myService.get();

Remember to inject myService in the controllers by passing it as a parameter.

How to determine day of week by passing specific date?

java.time

Using java.time framework built into Java 8 and later.

The DayOfWeek enum can generate a String of the day’s name automatically localized to the human language and cultural norms of a Locale. Specify a TextStyle to indicate you want long form or abbreviated name.

import java.time.LocalDate
import java.time.format.DateTimeFormatter
import java.time.format.TextStyle
import java.util.Locale
import java.time.DayOfWeek;

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("d/M/yyyy");
LocalDate date = LocalDate.parse("23/2/2010", formatter); // LocalDate = 2010-02-23
DayOfWeek dow = date.getDayOfWeek();  // Extracts a `DayOfWeek` enum object.
String output = dow.getDisplayName(TextStyle.SHORT, Locale.US); // String = Tue

Display a RecyclerView in Fragment

This was asked some time ago now, but based on the answer that @nacho_zona3 provided, and previous experience with fragments, the issue is that the views have not been created by the time you are trying to find them with the findViewById() method in onCreate() to fix this, move the following code:

// 1. get a reference to recyclerView
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.list);

// 2. set layoutManger
recyclerView.setLayoutManager(new LinearLayoutManager(this));

// this is data fro recycler view
ItemData itemsData[] = { new ItemData("Indigo",R.drawable.circle),
        new ItemData("Red",R.drawable.color_ic_launcher),
        new ItemData("Blue",R.drawable.indigo),
        new ItemData("Green",R.drawable.circle),
        new ItemData("Amber",R.drawable.color_ic_launcher),
        new ItemData("Deep Orange",R.drawable.indigo)};


// 3. create an adapter
MyAdapter mAdapter = new MyAdapter(itemsData);
// 4. set adapter
recyclerView.setAdapter(mAdapter);
// 5. set item animator to DefaultAnimator
recyclerView.setItemAnimator(new DefaultItemAnimator()); 

to your fragment's onCreateView() call. A small amount of refactoring is required because all variables and methods called from this method have to be static. The final code should look like:

 public class ColorsFragment extends Fragment {

     public ColorsFragment() {}

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
         Bundle savedInstanceState) {

         View rootView = inflater.inflate(R.layout.fragment_colors, container, false);
         // 1. get a reference to recyclerView
         RecyclerView recyclerView = (RecyclerView) rootView.findViewById(R.id.list);

         // 2. set layoutManger
         recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

         // this is data fro recycler view
         ItemData itemsData[] = {
             new ItemData("Indigo", R.drawable.circle),
                 new ItemData("Red", R.drawable.color_ic_launcher),
                 new ItemData("Blue", R.drawable.indigo),
                 new ItemData("Green", R.drawable.circle),
                 new ItemData("Amber", R.drawable.color_ic_launcher),
                 new ItemData("Deep Orange", R.drawable.indigo)
         };


         // 3. create an adapter
         MyAdapter mAdapter = new MyAdapter(itemsData);
         // 4. set adapter
         recyclerView.setAdapter(mAdapter);
         // 5. set item animator to DefaultAnimator
         recyclerView.setItemAnimator(new DefaultItemAnimator());

         return rootView;
     }
 }

So the main thing here is that anywhere you call findViewById() you will need to use rootView.findViewById()

How to create an Array, ArrayList, Stack and Queue in Java?

I am guessing you're confused with the parameterization of the types:

// This works, because there is one class/type definition in the parameterized <> field
ArrayList<String> myArrayList = new ArrayList<String>(); 


// This doesn't work, as you cannot use primitive types here
ArrayList<char> myArrayList = new ArrayList<char>();

Display tooltip on Label's hover?

You don't have to use hidden field. Use "title" property. It will show browser default tooltip. You can then use jQuery plugin (like before mentioned bootstrap tooltip) to show custom formatted tooltip.

<label for="male" title="Hello This Will Have Some Value">Hello ...</label>

Hint: you can also use css to trim text, that does not fit into the box (text-overflow property). See http://jsfiddle.net/8eeHs/

How do you auto format code in Visual Studio?

On mac : Shift + Option + F

On ubuntu : Ctrl + Shift + I

How do I find what Java version Tomcat6 is using?

Or you could use the Probe application and just look at its System Info page. Much easier than writing code, and once you start using it you'll never go back to Tomcat Manager.

java.lang.VerifyError: Expecting a stackmap frame at branch target JDK 1.7

The only difference between files that causing the issue is the 8th byte of file

CA FE BA BE 00 00 00 33 - Java 7

vs.

CA FE BA BE 00 00 00 32 - Java 6

Setting -XX:-UseSplitVerifier resolves the issue. However, the cause of this issue is https://bugs.eclipse.org/bugs/show_bug.cgi?id=339388

Logging with Retrofit 2

Retrofit's interceptor is a great feature which allow you work with http requests. There are two types of them: application and network interceptors.

I would recommend to use Charles Web Debugging Proxy Application if you need logging your requests/responses. The output is very similar to Stetho but it is more powerful instrument which you do not need to add as a dependency to an application

How to get browser width using JavaScript code?

An important addition to Travis' answer; you need to put the getWidth() up in your document body to make sure that the scrollbar width is counted, else scrollbar width of the browser subtracted from getWidth(). What i did ;

<body>
<script>
function getWidth(){
return Math.max(document.body.scrollWidth,
document.documentElement.scrollWidth,
document.body.offsetWidth,
document.documentElement.offsetWidth,
document.documentElement.clientWidth);
}
var aWidth=getWidth();
</script>
</body>

and call aWidth variable anywhere afterwards.

JavaFX 2.1 TableView refresh items

The solution by user1236048 is correct, but the key point isn't called out. In your POJO classes used for the table's observable list, you not only have to set getter and setter methods, but a new one called Property. In Oracle's tableview tutorial (http://docs.oracle.com/javafx/2/ui_controls/table-view.htm), they left that key part off!

Here's what the Person class should look like:

public static class Person {

    private final SimpleStringProperty firstName;
    private final SimpleStringProperty lastName;
    private final SimpleStringProperty email;

    private Person(String fName, String lName, String email) {
        this.firstName = new SimpleStringProperty(fName);
        this.lastName = new SimpleStringProperty(lName);
        this.email = new SimpleStringProperty(email);
    }

    public String getFirstName() {
        return firstName.get();
    }

    public void setFirstName(String fName) {
        firstName.set(fName);
    }

    public SimpleStringProperty firstNameProperty(){
        return firstName;
    }

    public String getLastName() {
        return lastName.get();
    }

    public void setLastName(String fName) {
        lastName.set(fName);
    }

    public SimpleStringProperty lastNameProperty(){
        return lastName;
    }

    public String getEmail() {
        return email.get();
    }

    public void setEmail(String fName) {
        email.set(fName);
    }

    public SimpleStringProperty emailProperty(){
            return email;
        }

}

(SC) DeleteService FAILED 1072

The 3rd party application uninstaller had removed the files for the service and then left the service in this pending deletion state.

After trying to close all applications, identifing PID of service(couldn't) for kill, logging off all other users and logging off and on, rebooting was the only fix that worked for me.

How to get all privileges back to the root user in MySQL?

If you facing grant permission access denied problem, you can try mysql to fix the problem:

grant all privileges on . to root@'localhost' identified by 'Your password';

grant all privileges on . to root@'IP ADDRESS' identified by 'Your password?';

your can try this on any mysql user, its working.

Use below command to login mysql with iP address.

mysql -h 10.0.0.23 -u root -p

Is it possible to use a batch file to establish a telnet session, send a command and have the output written to a file?

The microsoft telnet.exe is not scriptable without using another script (which needs keyboard focus), as shown in another answer to this question, but there is a free

Telnet Scripting Tool v.1.0 by Albert Yale

that you can google for and which is both scriptable and loggable and can be launched from a batch file without needing keyboard focus.

The problem with telnet.exe and a second script when keyboard focus is being used is that if someone is using the computer at the time the script runs, then it is highly likely that the script will fail due to mouse clicks and keyboard use at that moment in time.

How can I prevent the textarea from stretching beyond his parent DIV element? (google-chrome issue only)

I'm hoping you are having the same problem that I had... my issue was simple: Make a fixed textarea with locked percentages inside the container (I'm new to CSS/JS/HTML, so bear with me, if I don't get the lingo correct) so that no matter the device it's displaying on, the box filling the container (the table cell) takes up the correct amount of space. Here's how I solved it:

<table width=100%>
    <tr class="idbbs">
        B.S.:
    </tr></br>
    <tr>
        <textarea id="bsinpt"></textarea>
    </tr>
</table>

Then CSS Looks like this...

#bsinpt
{
    color: gainsboro;
    float: none;
    background: black;
    text-align: left;
    font-family: "Helvetica", "Tahoma", "Verdana", "Arial Black", sans-serif;
    font-size: 100%;
  position: absolute;
  min-height: 60%;
  min-width: 88%;
  max-height: 60%;
  max-width: 88%;
  resize: none;
    border-top-color: lightsteelblue;
    border-top-width: 1px;
    border-left-color: lightsteelblue;
    border-left-width: 1px;
    border-right-color: lightsteelblue;
    border-right-width: 1px;
    border-bottom-color: lightsteelblue;
    border-bottom-width: 1px;
}

Sorry for the sloppy code block here, but I had to show you what's important and I don't know how to insert quoted CSS code on this website. In any case, to ensure you see what I'm talking about, the important CSS is less indented here...

What I then did (as shown here) is very specifically tweak the percentages until I found the ones that worked perfectly to fit display, no matter what device screen is used.

Granted, I think the "resize: none;" is overkill, but better safe than sorry and now the consumers will not have anyway to resize the box, nor will it matter what device they are viewing it from.

It works great.

Is there are way to make a child DIV's width wider than the parent DIV using CSS?

Based on your suggestion original suggestion (setting negative margins), I have tried and come up with a similar method using percentage units for dynamic browser width:

HTML

<div class="grandparent">
    <div class="parent">
        <div class="child">
            <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Dolore neque repellat ipsum natus magni soluta explicabo architecto, molestias laboriosam rerum. Tempore eos labore temporibus alias necessitatibus illum enim, est harum perspiciatis, sit, totam earum corrupti placeat architecto aut minus dignissimos mollitia asperiores sint ea. Libero hic laudantium, ipsam nostrum earum distinctio. Cum expedita, ratione, accusamus dicta similique distinctio est dolore assumenda soluta dolorem quisquam ex possimus aliquid provident quo? Enim tempora quo cupiditate eveniet aperiam.</p>
        </div>
    </div>
</div>

CSS:

.child-div{
   margin: 0 -100%;
   padding: 0 -100%;
}

.parent {
    width: 60%;
    background-color: red;
    margin: 0 auto;
    padding: 50px;
    position:relative;
}

.grandparent {
        overflow-x:hidden;
        background-color: blue;
        width: 100%;
        position:relative;
    }

The negative margins will let the content flow out of the Parent DIV. Therefore I set the padding: 0 100%; to push the content back to the original boundaries of the Chlid DIV.

The negative margins will also make the .child-div's total width expands out of the browser's viewport, resulting in a horizontal scroll. Hence we need to clip the extruding width by applying an overflow-x: hidden to a Grandparent DIV (which is the parent of the Parent Div):

Here is the JSfiddle

I haved tried Nils Kaspersson's left: calc(-50vw + 50%); it worked perfectly fine in Chrome & FF (not sure about IE yet) until I found out Safari browsers doesn't do it properly. Hope they fixed this soon as I actually like this simple method.

This also may resolve your issue where the Parent DIV element has to be position:relative

The 2 drawbacks of this workaround method is:

  • Require extra markup (i.e a grandparent element (just like the good ol' table vertical align method isn't it...)
  • The left and right border of the Child DIV will never show, simply because they are outside of the browser's viewport.

Please let me know if there's any issue you find with this method ;). Hope it helps.

How to get the current time in milliseconds from C in Linux?

This version need not math library and checked the return value of clock_gettime().

#include <time.h>
#include <stdlib.h>
#include <stdint.h>

/**
 * @return milliseconds
 */
uint64_t get_now_time() {
  struct timespec spec;
  if (clock_gettime(1, &spec) == -1) { /* 1 is CLOCK_MONOTONIC */
    abort();
  }

  return spec.tv_sec * 1000 + spec.tv_nsec / 1e6;
}

Exporting the values in List to excel

The most straightforward way (in my opinion) would be to simply put together a CSV file. If you want to get into formatting and actually writing to a *.xlsx file, there are more complicated solutions (and APIs) to do that for you.

How does DateTime.Now.Ticks exactly work?

Not really an answer to your question as asked, but thought I'd chip in about your general objective.

There already is a method to generate random file names in .NET.

See System.Path.GetTempFileName and GetRandomFileName.

Alternatively, it is a common practice to use a GUID to name random files.

Start systemd service after specific service?

After= dependency is only effective when service including After= and service included by After= are both scheduled to start as part of your boot up.

Ex:

a.service
[Unit]
After=b.service

This way, if both a.service and b.service are enabled, then systemd will order b.service after a.service.

If I am not misunderstanding, what you are asking is how to start b.service when a.service starts even though b.service is not enabled.

The directive for this is Wants= or Requires= under [Unit].

website.service
[Unit]
Wants=mongodb.service
After=mongodb.service

The difference between Wants= and Requires= is that with Requires=, a failure to start b.service will cause the startup of a.service to fail, whereas with Wants=, a.service will start even if b.service fails. This is explained in detail on the man page of .unit.

How do I force a favicon refresh?

Depending on the browser they are handled differently, but typically I find that going to the default page of the site, and doing a hard refresh. CTRL + F5, will typically get it to update.

How do you clear your Visual Studio cache on Windows Vista?

I experienced this today. The value in Config was the updated one but the application would return the older value, stop and starting the solution did nothing.

So I cleared the .Net Temp folder.

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files

It shouldn't create bugs but to be safe close your solution down first. Clear the Temporary ASP.NET Files then load up your solution.

My issue was sorted.

How to randomize (shuffle) a JavaScript array?

One could (or should) use it as a protoype from Array:

From ChristopheD:

Array.prototype.shuffle = function() {
  var i = this.length, j, temp;
  if ( i == 0 ) return this;
  while ( --i ) {
     j = Math.floor( Math.random() * ( i + 1 ) );
     temp = this[i];
     this[i] = this[j];
     this[j] = temp;
  }
  return this;
}

How to customize the background color of a UITableViewCell?

You need to set the backgroundColor of the cell's contentView to your color. If you use accessories (such as disclosure arrows, etc), they'll show up as white, so you may need to roll custom versions of those.

Java POI : How to read Excel cell value and not the formula computing it?

If you want to extract a raw-ish value from a HSSF cell, you can use something like this code fragment:

CellBase base = (CellBase) cell;
CellType cellType = cell.getCellType();
base.setCellType(CellType.STRING);
String result = cell.getStringCellValue();
base.setCellType(cellType);

At least for strings that are completely composed of digits (and automatically converted to numbers by Excel), this returns the original string (e.g. "12345") instead of a fractional value (e.g. "12345.0"). Note that setCellType is available in interface Cell(as of v. 4.1) but deprecated and announced to be eliminated in v 5.x, whereas this method is still available in class CellBase. Obviously, it would be nicer either to have getRawValue in the Cell interface or at least to be able use getStringCellValue on non STRING cell types. Unfortunately, all replacements of setCellType mentioned in the description won't cover this use case (maybe a member of the POI dev team reads this answer).

jQuery - select all text from a textarea

I ended up using this:

$('.selectAll').toggle(function() {
  $(this).select();
}, function() {
  $(this).unselect();
});

CSS Div width percentage and padding without breaking layout

If you want the #header to be the same width as your container, with 10px of padding, you can leave out its width declaration. That will cause it to implicitly take up its entire parent's width (since a div is by default a block level element).

Then, since you haven't defined a width on it, the 10px of padding will be properly applied inside the element, rather than adding to its width:

#container {
    position: relative;
    width: 80%;
}

#header {
    position: relative;
    height: 50px;
    padding: 10px;
}

You can see it in action here.

The key when using percentage widths and pixel padding/margins is not to define them on the same element (if you want to accurately control the size). Apply the percentage width to the parent and then the pixel padding/margin to a display: block child with no width set.


Update

Another option for dealing with this is to use the box-sizing CSS rule:

#container { 
    -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
    -moz-box-sizing: border-box;    /* Firefox, other Gecko */
    box-sizing: border-box;         /* Opera/IE 8+ */

    /* Since this element now uses border-box sizing, the 10px of horizontal
       padding will be drawn inside the 80% width */
    width: 80%;
    padding: 0 10px;
}

Here's a post talking about how box-sizing works.

How can I view the Git history in Visual Studio Code?

Git Graph seems like a decent extension. After installing, you can open the graph view from the bottom status bar.

Why is my Button text forced to ALL CAPS on Lollipop?

By default, Button in android provides all caps keyword. If you want button text to be in lower case or mixed case you can disable textAllCaps flag using android:textAllCaps="false"

C# Linq Group By on multiple columns

var consolidatedChildren =
    from c in children
    group c by new
    {
        c.School,
        c.Friend,
        c.FavoriteColor,
    } into gcs
    select new ConsolidatedChild()
    {
        School = gcs.Key.School,
        Friend = gcs.Key.Friend,
        FavoriteColor = gcs.Key.FavoriteColor,
        Children = gcs.ToList(),
    };

var consolidatedChildren =
    children
        .GroupBy(c => new
        {
            c.School,
            c.Friend,
            c.FavoriteColor,
        })
        .Select(gcs => new ConsolidatedChild()
        {
            School = gcs.Key.School,
            Friend = gcs.Key.Friend,
            FavoriteColor = gcs.Key.FavoriteColor,
            Children = gcs.ToList(),
        });

How to determine the first and last iteration in a foreach loop?

An attempt to find the first would be:

$first = true; 
foreach ( $obj as $value )
{
  if ( $first )
  {
    // do something
    $first = false; //in order not to get into the if statement for the next loops
  }
  else
  {
    // do something else for all loops except the first
  }
}

What design patterns are used in Spring framework?

The DI thing actually is some kind of strategy pattern. Whenever you want to be some logic/implementation exchangeable you typically find an interface and an appropriate setter method on the host class to wire your custom implementation of that interface.

AND/OR in Python?

Try this solution:

for m in ["a", "á", "à", "ã", "â"]:
    try:
        somelist.remove(m)
    except:
        pass

Just for your information. and and or operators are also using to return values. It is useful when you need to assign value to variable but you have some pre-requirements

operator or returns first not null value

#init values
a,b,c,d = (1,2,3,None)

print(d or a or b or c)
#output value of a - 1

print(b or a or c or d)
#output value of b - 2

Operator and returns last value in the sequence if any of the members don't have None value or if they have at least one None value we get None

print(a and d and b and c)
#output: None

print(a or b or c)
#output value of c - 3

Generate a UUID on iOS from Swift

You could also just use the NSUUID API:

let uuid = NSUUID()

If you want to get the string value back out, you can use uuid.UUIDString.

Note that NSUUID is available from iOS 6 and up.

Generic Property in C#

Okay, I'll bite. You want something like this: If you declare a "property" like this:

Update: I'm now pretty sure that Fredrik Mörk answered your question and gave a solution. I'm not really happy with the idea, but it seems to answer exactly what I understood from your question.

public class PropertyFoo {
  public MyProp<String> Name;
}

this ends up as

public class PropertyFoo {
  public string Name {
    get { /* do predefined stuff here */ }
    set { /*other predefined stuff here */ }
  }
}

No. Not possible and not a property, really. Look for template/snippet support in your IDE.

How to implement a simple scenario the OO way

You might implement your class model by composition, having the book object have a map of chapter objects contained within it (map chapter number to chapter object). Your search function could be given a list of books into which to search by asking each book to search its chapters. The book object would then iterate over each chapter, invoking the chapter.search() function to look for the desired key and return some kind of index into the chapter. The book's search() would then return some data type which could combine a reference to the book and some way to reference the data that it found for the search. The reference to the book could be used to get the name of the book object that is associated with the collection of chapter search hits.

How to change fontFamily of TextView in Android

An easy way to manage the fonts would be to declare them via resources, as such:

<!--++++++++++++++++++++++++++-->
<!--added on API 16 (JB - 4.1)-->
<!--++++++++++++++++++++++++++-->
<!--the default font-->
<string name="fontFamily__roboto_regular">sans-serif</string>
<string name="fontFamily__roboto_light">sans-serif-light</string>
<string name="fontFamily__roboto_condensed">sans-serif-condensed</string>

<!--+++++++++++++++++++++++++++++-->
<!--added on API 17 (JBMR1 - 4.2)-->
<!--+++++++++++++++++++++++++++++-->
<string name="fontFamily__roboto_thin">sans-serif-thin</string>

<!--+++++++++++++++++++++++++++-->
<!--added on Lollipop (LL- 5.0)-->
<!--+++++++++++++++++++++++++++-->
<string name="fontFamily__roboto_medium">sans-serif-medium</string>
<string name="fontFamily__roboto_black">sans-serif-black</string>
<string name="fontFamily__roboto_condensed_light">sans-serif-condensed-light</string>

This is based on the source code here and here

Excel Calculate the date difference from today from a cell of "7/6/2012 10:26:42"

You can use the datedif function to find out difference in days.

=DATEDIF(A1,TODAY(),"d")

Quote from excel.datedif.com

The mysterious datedif function in Microsoft Excel

The Datedif function is used to calculate interval between two dates in days, months or years.

This function is available in all versions of Excel but is not documented. It is not even listed in the "Insert Function" dialog box. Hence it must be typed manually in the formula box. Syntax

DATEDIF( start_date, end_date, interval_unit )

start_date from date end_date to date (must be after start_date) interval_unit Unit to be used for output interval Values for interval_unit

interval_unit Description

D Number of days

M Number of complete months

Y Number of complete years

YD Number of days excluding years

MD Number of days excluding months and years

YM Number of months excluding years

Errors

Error Description

#NUM! The end_date is later than (greater than) the start_date or interval_unit has an invalid value. #VALUE! end_date or start_date is invalid.

Is there a way to represent a directory tree in a Github README.md?

Simple tree command will do the job. For example: tree -o readme.md will print the tree structure of your current working directory and write it to readme.md. Then open readme.md file in one of text editor like Sublime and wrap its content within a pair of triple backticks (```).

FYI: you might have to brew install tree in OSX if it's not already installed. In Linux and Windows it should just work fine. Also in windows you might have to replace hyphen with forward slash.

I hope this helps.

Typescript empty object for a typed variable

If you declare an empty object literal and then assign values later on, then you can consider those values optional (may or may not be there), so just type them as optional with a question mark:

type User = {
    Username?: string;
    Email?: string;
}

Number prime test in JavaScript

This will cover all the possibility of a prime number . (order of the last 3 if statements is important)

   function isPrime(num){  
    if (num==0 || num==1) return false;
    if (num==2 || num==3 ) return true; 
    if (num % Math.sqrt(num)==0 ) return false;
    for (let i=2;i< Math.floor(Math.sqrt(num));i++) if ( num % i==0 ) return false;
    if ((num * num - 1) % 24 == 0) return true;        
   }

Getting "Skipping JaCoCo execution due to missing execution data file" upon executing JaCoCo

I've tried all answers but only the following combination of advice has worked for me. Why? I had very specific requirements:

  1. JaCoCo generates report when build is run from command line: mvn clean verify (Maven 3.6.0)
  2. Intellij IDEA (2019.01) runs my tests as well
  3. It all works in presence of another javaagent defined in surefire plugin

Solution - prepend argLine value in surefire configuration with "late replacement" maven property @{...} as explained in surefire FAQ (my fixed configuration)

How do I use properties set by other plugins in argLine? Maven does property replacement for

${...} values in pom.xml before any plugin is run. So Surefire would never see the place-holders in its argLine property. Since the Version 2.17 using an alternate syntax for these properties,

@{...} allows late replacement of properties when the plugin is executed, so properties that have been modified by other plugins will be picked up correctly.

Failed first try - define jaCoCoArgLine property in prepare-agent goal configuration of jacoco - the scenario failed my second requirement, IntelliJ IDEA couldn't figure out agent for jmockit I use in the project for static method mocking

MySQL GROUP BY two columns

First, let's make some test data:

create table client (client_id integer not null primary key auto_increment,
                     name varchar(64));
create table portfolio (portfolio_id integer not null primary key auto_increment,
                        client_id integer references client.id,
                        cash decimal(10,2),
                        stocks decimal(10,2));
insert into client (name) values ('John Doe'), ('Jane Doe');
insert into portfolio (client_id, cash, stocks) values (1, 11.11, 22.22),
                                                       (1, 10.11, 23.22),
                                                       (2, 30.30, 40.40),
                                                       (2, 40.40, 50.50);

If you didn't need the portfolio ID, it would be easy:

select client_id, name, max(cash + stocks)
from client join portfolio using (client_id)
group by client_id

+-----------+----------+--------------------+
| client_id | name     | max(cash + stocks) |
+-----------+----------+--------------------+
|         1 | John Doe |              33.33 | 
|         2 | Jane Doe |              90.90 | 
+-----------+----------+--------------------+

Since you need the portfolio ID, things get more complicated. Let's do it in steps. First, we'll write a subquery that returns the maximal portfolio value for each client:

select client_id, max(cash + stocks) as maxtotal
from portfolio
group by client_id

+-----------+----------+
| client_id | maxtotal |
+-----------+----------+
|         1 |    33.33 | 
|         2 |    90.90 | 
+-----------+----------+

Then we'll query the portfolio table, but use a join to the previous subquery in order to keep only those portfolios the total value of which is the maximal for the client:

 select portfolio_id, cash + stocks from portfolio 
 join (select client_id, max(cash + stocks) as maxtotal 
       from portfolio
       group by client_id) as maxima
 using (client_id)
 where cash + stocks = maxtotal

+--------------+---------------+
| portfolio_id | cash + stocks |
+--------------+---------------+
|            5 |         33.33 | 
|            6 |         33.33 | 
|            8 |         90.90 | 
+--------------+---------------+

Finally, we can join to the client table (as you did) in order to include the name of each client:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal

+-----------+----------+--------------+---------------+
| client_id | name     | portfolio_id | cash + stocks |
+-----------+----------+--------------+---------------+
|         1 | John Doe |            5 |         33.33 | 
|         1 | John Doe |            6 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 
+-----------+----------+--------------+---------------+

Note that this returns two rows for John Doe because he has two portfolios with the exact same total value. To avoid this and pick an arbitrary top portfolio, tag on a GROUP BY clause:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal
group by client_id, cash + stocks

+-----------+----------+--------------+---------------+
| client_id | name     | portfolio_id | cash + stocks |
+-----------+----------+--------------+---------------+
|         1 | John Doe |            5 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 
+-----------+----------+--------------+---------------+

How to write inline if statement for print?

The 'else' statement is mandatory. You can do stuff like this :

>>> b = True
>>> a = 1 if b else None
>>> a
1
>>> b = False
>>> a = 1 if b else None
>>> a
>>> 

EDIT:

Or, depending of your needs, you may try:

>>> if b: print(a)

Loading scripts after page load?

Focusing on one of the accepted answer's jQuery solutions, $.getScript() is an .ajax() request in disguise. It allows to execute other function on success by adding a second parameter:

$.getScript(url, function() {console.log('loaded script!')})

Or on the request's handlers themselves, i.e. success (.done() - script was loaded) or failure (.fail()):

_x000D_
_x000D_
$.getScript(_x000D_
    "https://code.jquery.com/color/jquery.color.js",_x000D_
    () => console.log('loaded script!')_x000D_
  ).done((script,textStatus ) => {_x000D_
    console.log( textStatus );_x000D_
    $(".block").animate({backgroundColor: "green"}, 1000);_x000D_
  }).fail(( jqxhr, settings, exception ) => {_x000D_
    console.log(exception + ': ' + jqxhr.status);_x000D_
  }_x000D_
);
_x000D_
.block {background-color: blue;width: 50vw;height: 50vh;margin: 1rem;}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="block"></div>
_x000D_
_x000D_
_x000D_

Regular expression [Any number]

var mask = /^\d+$/;
if ( myString.exec(mask) ){
   /* That's a number */
}

The service cannot be started, either because it is disabled or because it has no enabled devices associated with it

This error can occur on anything that requires elevated privileges in Windows.

It happens when the "Application Information" service is disabled in Windows services. There are a few viruses that use this as an attack vector to prevent people from removing the virus. It also prevents people from installing software to remove viruses.

The normal way to fix this would be to run services.msc, or to go into Administrative Tools and run "Services". However, you will not be able to do that if the "Application Information" service is disabled.

Instead, reboot your computer into Safe Mode (reboot and press F8 until the Windows boot menu appears, select Safe Mode with Networking). Then run services.msc and look for services that are designated as "Disabled" in the Startup Type column. Change these "Disabled" services to "Automatic".

Make sure the "Application Information" service is set to a Startup Type of "Automatic".

When you are done enabling your services, click Ok at the bottom of the tool and reboot your computer back into normal mode. The problem should be resolved when Windows reboots.

Uncaught SoapFault exception: [HTTP] Error Fetching http headers

In my apache error log, I saw:

[Tue Feb 16 14:55:02 2010] [notice] child pid 9985 exit signal File size limit exceeded (25)

So I, removed all the contents of my largest log file 2.1GB /var/log/system.log. Now everything works.

datatable jquery - table header width not aligned with body width

I solved this problem by wrapping the "dataTable" Table with a div with overflow:auto:

.dataTables_scroll
{
    overflow:auto;
}

and adding this JS after your dataTable initialization:

jQuery('.dataTable').wrap('<div class="dataTables_scroll" />');

Don't use sScrollX or sScrollY, remove them and add a div wrapper yourself which does the same thing.

How to get the exact local time of client?

The most reliable way I've found to display the local time of a city or location is by tapping into a Time Zone API such as Google Time Zone API. It returns the correct time zone, and more importantly, Day Light Savings Time offset of any location, which just using JavaScript's Date() object cannot be done as far as I'm aware. There's a good tutorial on using the API to get and display the local time here:

var loc = '35.731252, 139.730291' // Tokyo expressed as lat,lng tuple
var targetDate = new Date() // Current date/time of user computer
var timestamp = targetDate.getTime() / 1000 + targetDate.getTimezoneOffset() * 60 // Current UTC date/time expressed as seconds since midnight, January 1, 1970 UTC
var apikey = 'YOUR_TIMEZONE_API_KEY_HERE'
var apicall = 'https://maps.googleapis.com/maps/api/timezone/json?location=' + loc + '&timestamp=' + timestamp + '&key=' + apikey

var xhr = new XMLHttpRequest() // create new XMLHttpRequest2 object
xhr.open('GET', apicall) // open GET request
xhr.onload = function() {
  if (xhr.status === 200) { // if Ajax request successful
    var output = JSON.parse(xhr.responseText) // convert returned JSON string to JSON object
    console.log(output.status) // log API return status for debugging purposes
    if (output.status == 'OK') { // if API reports everything was returned successfully
      var offsets = output.dstOffset * 1000 + output.rawOffset * 1000 // get DST and time zone offsets in milliseconds
      var localdate = new Date(timestamp * 1000 + offsets) // Date object containing current time of Tokyo (timestamp + dstOffset + rawOffset)
      console.log(localdate.toLocaleString()) // Display current Tokyo date and time
    }
  } else {
    alert('Request failed.  Returned status of ' + xhr.status)
  }
}
xhr.send() // send request

From: Displaying the Local Time of Any City using JavaScript and Google Time Zone API

"Repository does not have a release file" error

I have been having this issue for a couple of weeks and finally decided to sit down and try and fix it. I have no interest in config file editing as I'm primarily a Windows user.

In a fit of "clickyness" I noticed that the ubuntu server location was set "for United kingdom". I switched this over to "Main Server" and hey presto... it all stared updating.

So, it seems like the regionalised server (for the UK at least) has a very limited support window so if you are an infrequent user it is likely it will not have a valid upgrade path from your current version to the latest.

Edit: I only just noticted the previous reply, after posting. 100% agree.

Uncaught Error: Unexpected module 'FormsModule' declared by the module 'AppModule'. Please add a @Pipe/@Directive/@Component annotation

FormsModule should be added at imports array not declarations array.

  • imports array is for importing modules such as BrowserModule, FormsModule, HttpModule
  • declarations array is for your Components, Pipes, Directives

refer below change:

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})

Join a list of items with different types as string in Python

Calling str(...) is the Pythonic way to convert something to a string.

You might want to consider why you want a list of strings. You could instead keep it as a list of integers and only convert the integers to strings when you need to display them. For example, if you have a list of integers then you can convert them one by one in a for-loop and join them with ,:

print(','.join(str(x) for x in list_of_ints))

How to get document height and width without using jquery

Even the last example given on http://www.howtocreate.co.uk/tutorials/javascript/browserwindow is not working on Quirks mode. Easier to find than I thought, this seems to be the solution(extracted from latest jquery code):

Math.max(
    document.documentElement["clientWidth"],
    document.body["scrollWidth"],
    document.documentElement["scrollWidth"],
    document.body["offsetWidth"],
    document.documentElement["offsetWidth"]
);

just replace Width for "Height" to get Height.