Programs & Examples On #Google perftools

Google performance tool for CPU and Heap profiling

How do I create a link using javascript?

_x000D_
_x000D_
    <script>_x000D_
      _$ = document.querySelector  .bind(document) ;_x000D_
_x000D_
        var AppendLinkHere = _$("body") // <- put in here some CSS selector that'll be more to your needs_x000D_
        var a   =  document.createElement( 'a' )_x000D_
        a.text  = "Download example" _x000D_
        a.href  = "//bit\.do/DeezerDL"_x000D_
_x000D_
        AppendLinkHere.appendChild( a )_x000D_
        _x000D_
_x000D_
     // a.title = 'Well well ... _x000D_
        a.setAttribute( 'title', _x000D_
                         'Well well that\'s a link'_x000D_
                      );_x000D_
    </script>
_x000D_
_x000D_
_x000D_

  1. The 'Anchor Object' has its own*(inherited)* properties for setting the link, its text. So just use them. .setAttribute is more general but you normally don't need it. a.title ="Blah" will do the same and is more clear! Well a situation that'll demand .setAttribute is this: var myAttrib = "title"; a.setAttribute( myAttrib , "Blah")

  2. Leave the protocol open. Instead of http://example.com/path consider to just use //example.com/path. Check if example.com can be accessed by http: as well as https: but 95 % of sites will work on both.

  3. OffTopic: That's not really relevant about creating links in JS but maybe good to know: Well sometimes like in the chromes dev-console you can use $("body") instead of document.querySelector("body") A _$ = document.querySelectorwill 'honor' your efforts with an Illegal invocation error the first time you use it. That's because the assignment just 'grabs' .querySelector (a ref to the class method). With .bind(... you'll also involve the context (here it's document) and you get an object method that'll work as you might expect it.

Make Bootstrap Popover Appear/Disappear on Hover instead of Click

I'd like to add that for accessibility, I think you should add focus trigger :

i.e. $("#popover").popover({ trigger: "hover focus" });

How to create a DateTime equal to 15 minutes ago?

If you are using time.time() and wants timestamp as output

Simply use

CONSTANT_SECONDS = 900 # time  in seconds (900 seconds = 15 min)

current_time = int(time.time())
time_before_15_min = current_time - CONSTANT_SECONDS

You can change 900 seconds as per your required time.

How to identify a strong vs weak relationship on ERD?

  1. Weak (Non-Identifying) Relationship

    • Entity is existence-independent of other enties

    • PK of Child doesn’t contain PK component of Parent Entity

  2. Strong (Identifying) Relationship

    • Child entity is existence-dependent on parent

    • PK of Child Entity contains PK component of Parent Entity

    • Usually occurs utilizing a composite key for primary key, which means one of this composite key components must be the primary key of the parent entity.

How to use wget in php?

You can use curl in order to both fetch the data, and be identified (for both "basic" and "digest" auth), without requiring extended permissions (like exec or allow_url_fopen).

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/file.xml");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
curl_setopt($ch, CURLOPT_USERPWD, "user:pass");
$result = curl_exec($ch);
curl_close($ch);

Your result will then be stored in the $result variable.

Android Webview - Webpage should fit the device screen

WebView browser = (WebView) findViewById(R.id.webview);
browser.getSettings().setLoadWithOverviewMode(true);
browser.getSettings().setUseWideViewPort(true);
browser.getSettings().setMinimumFontSize(40);

This works great for me since the text size has been set to really small by .setLoadWithOverViewMode and .setUseWideViewPort.

how to get file path from sd card in android

There are different Names of SD-Cards.

This Code check every possible Name (I don't guarantee that these are all names but the most are included)

It prefers the main storage.

 private String SDPath() {
    String sdcardpath = "";

    //Datas
    if (new File("/data/sdext4/").exists() && new File("/data/sdext4/").canRead()){
        sdcardpath = "/data/sdext4/";
    }
    if (new File("/data/sdext3/").exists() && new File("/data/sdext3/").canRead()){
        sdcardpath = "/data/sdext3/";
    }
    if (new File("/data/sdext2/").exists() && new File("/data/sdext2/").canRead()){
        sdcardpath = "/data/sdext2/";
    }
    if (new File("/data/sdext1/").exists() && new File("/data/sdext1/").canRead()){
        sdcardpath = "/data/sdext1/";
    }
    if (new File("/data/sdext/").exists() && new File("/data/sdext/").canRead()){
        sdcardpath = "/data/sdext/";
    }

    //MNTS

    if (new File("mnt/sdcard/external_sd/").exists() && new File("mnt/sdcard/external_sd/").canRead()){
        sdcardpath = "mnt/sdcard/external_sd/";
    }
    if (new File("mnt/extsdcard/").exists() && new File("mnt/extsdcard/").canRead()){
        sdcardpath = "mnt/extsdcard/";
    }
    if (new File("mnt/external_sd/").exists() && new File("mnt/external_sd/").canRead()){
        sdcardpath = "mnt/external_sd/";
    }
    if (new File("mnt/emmc/").exists() && new File("mnt/emmc/").canRead()){
        sdcardpath = "mnt/emmc/";
    }
    if (new File("mnt/sdcard0/").exists() && new File("mnt/sdcard0/").canRead()){
        sdcardpath = "mnt/sdcard0/";
    }
    if (new File("mnt/sdcard1/").exists() && new File("mnt/sdcard1/").canRead()){
        sdcardpath = "mnt/sdcard1/";
    }
    if (new File("mnt/sdcard/").exists() && new File("mnt/sdcard/").canRead()){
        sdcardpath = "mnt/sdcard/";
    }

    //Storages
    if (new File("/storage/removable/sdcard1/").exists() && new File("/storage/removable/sdcard1/").canRead()){
        sdcardpath = "/storage/removable/sdcard1/";
    }
    if (new File("/storage/external_SD/").exists() && new File("/storage/external_SD/").canRead()){
        sdcardpath = "/storage/external_SD/";
    }
    if (new File("/storage/ext_sd/").exists() && new File("/storage/ext_sd/").canRead()){
        sdcardpath = "/storage/ext_sd/";
    }
    if (new File("/storage/sdcard1/").exists() && new File("/storage/sdcard1/").canRead()){
        sdcardpath = "/storage/sdcard1/";
    }
    if (new File("/storage/sdcard0/").exists() && new File("/storage/sdcard0/").canRead()){
        sdcardpath = "/storage/sdcard0/";
    }
    if (new File("/storage/sdcard/").exists() && new File("/storage/sdcard/").canRead()){
        sdcardpath = "/storage/sdcard/";
    }
    if (sdcardpath.contentEquals("")){
        sdcardpath = Environment.getExternalStorageDirectory().getAbsolutePath();
    }

    Log.v("SDFinder","Path: " + sdcardpath);
    return sdcardpath;
}

Disable a link in Bootstrap

I think you need the btn class.
It would be like this:

<a class="btn disabled" href="#">Disabled link</a>

How to make a great R reproducible example

To quickly create a dput of your data you can just copy (a piece of) the data to your clipboard and run the following in R:

for data in Excel:

dput(read.table("clipboard",sep="\t",header=TRUE))

for data in a txt file:

dput(read.table("clipboard",sep="",header=TRUE))

You can change the sep in the latter if necessary. This will only work if your data is in the clipboard of course.

Is there any way to wait for AJAX response and halt execution?

Method 1:

function functABC(){
    $.ajax({
        url: 'myPage.php',
        data: {id: id},
        success: function(data) {
            return data;
        },
        complete: function(){
              // do the job here
         }
    });
}

var response = functABC();

Method 2

function functABC(){
    $.ajax({
        url: 'myPage.php',
        data: {id: id},
        async: false,
        success: function(data) {
            return data;
        }        
    });

   // do the job here
}

Using PowerShell to remove lines from a text file if it contains a string

The pipe character | has a special meaning in regular expressions. a|b means "match either a or b". If you want to match a literal | character, you need to escape it:

... | Select-String -Pattern 'H\|159' -NotMatch | ...

Adding a slide effect to bootstrap dropdown

Update 2018 Bootstrap 4

In Boostrap 4, the .open class has been replaced with .show. I wanted to implement this using only CSS transistions without the need for extra JS or jQuery...

.show > .dropdown-menu {
  max-height: 900px;
  visibility: visible;
}

.dropdown-menu {
  display: block;
  max-height: 0;
  visibility: hidden;
  transition: all 0.5s ease-in-out;
  overflow: hidden;
}

Demo: https://www.codeply.com/go/3i8LzYVfMF

Note: max-height can be set to any large value that's enough to accommodate the dropdown content.

Get SELECT's value and text in jQuery

on the basis of your only jQuery tag :)

HTML

<select id="my-select">
<option value="1">This is text 1</option>
<option value="2">This is text 2</option>
<option value="3">This is text 3</option>
</select>

For text --

$(document).ready(function() {
    $("#my-select").change(function() {
        alert($('#my-select option:selected').html());
    });
});

For value --

$(document).ready(function() {
    $("#my-select").change(function() {
        alert($(this).val());
    });
});

How to remove numbers from string using Regex.Replace?

var result = Regex.Replace("123- abcd33", @"[0-9\-]", string.Empty);

Passing multiple parameters to pool.map() function in Python

You could use a map function that allows multiple arguments, as does the fork of multiprocessing found in pathos.

>>> from pathos.multiprocessing import ProcessingPool as Pool
>>> 
>>> def add_and_subtract(x,y):
...   return x+y, x-y
... 
>>> res = Pool().map(add_and_subtract, range(0,20,2), range(-5,5,1))
>>> res
[(-5, 5), (-2, 6), (1, 7), (4, 8), (7, 9), (10, 10), (13, 11), (16, 12), (19, 13), (22, 14)]
>>> Pool().map(add_and_subtract, *zip(*res))
[(0, -10), (4, -8), (8, -6), (12, -4), (16, -2), (20, 0), (24, 2), (28, 4), (32, 6), (36, 8)]

pathos enables you to easily nest hierarchical parallel maps with multiple inputs, so we can extend our example to demonstrate that.

>>> from pathos.multiprocessing import ThreadingPool as TPool
>>> 
>>> res = TPool().amap(add_and_subtract, *zip(*Pool().map(add_and_subtract, range(0,20,2), range(-5,5,1))))
>>> res.get()
[(0, -10), (4, -8), (8, -6), (12, -4), (16, -2), (20, 0), (24, 2), (28, 4), (32, 6), (36, 8)]

Even more fun, is to build a nested function that we can pass into the Pool. This is possible because pathos uses dill, which can serialize almost anything in python.

>>> def build_fun_things(f, g):
...   def do_fun_things(x, y):
...     return f(x,y), g(x,y)
...   return do_fun_things
... 
>>> def add(x,y):
...   return x+y
... 
>>> def sub(x,y):
...   return x-y
... 
>>> neato = build_fun_things(add, sub)
>>> 
>>> res = TPool().imap(neato, *zip(*Pool().map(neato, range(0,20,2), range(-5,5,1))))
>>> list(res)
[(0, -10), (4, -8), (8, -6), (12, -4), (16, -2), (20, 0), (24, 2), (28, 4), (32, 6), (36, 8)]

If you are not able to go outside of the standard library, however, you will have to do this another way. Your best bet in that case is to use multiprocessing.starmap as seen here: Python multiprocessing pool.map for multiple arguments (noted by @Roberto in the comments on the OP's post)

Get pathos here: https://github.com/uqfoundation

How to install easy_install in Python 2.7.1 on Windows 7

for 32-bit Python, the installer is here. after you run the installer, you will have easy_install.exe in your \Python27\Scripts directory

if you are looking for 64-bit installers, this is an excellent resource:

http://www.lfd.uci.edu/~gohlke/pythonlibs/

the author has installers for both Setuptools and Distribute. Either one will give you easy_install.exe

Get the current cell in Excel VB

I realize this doesn't directly apply from the title of the question, However some ways to deal with a variable range could be to select the range each time the code runs -- especially if you are interested in a user-selected range. If you are interested in that option, you can use the Application.InputBox (official documentation page here). One of the optional variables is 'type'. If the type is set equal to 8, the InputBox also has an excel-style range selection option. An example of how to use it in code would be:

Dim rng as Range
Set rng = Application.InputBox(Prompt:= "Please select a range", Type:=8)

Note:

If you assign the InputBox value to a none-range variable (without the Set keyword), instead of the ranges, the values from the ranges will be assigned, as in the code below (although selecting multiple ranges in this situation may require the values to be assigned to a variant):

Dim str as String
str = Application.InputBox(Prompt:= "Please select a range", Type:=8)

printf formatting (%d versus %u)

The difference is simple: they cause different warning messages to be emitted when compiling:

1156942.c:7:31: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int *’ [-Wformat=]
     printf("memory address = %d\n", &a); // prints "memory add=-12"
                               ^
1156942.c:8:31: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 2 has type ‘int *’ [-Wformat=]
     printf("memory address = %u\n", &a); // prints "memory add=65456"
                               ^

If you pass your pointer as a void* and use %p as the conversion specifier, then you get no error message:

#include <stdio.h>

int main()
{
    int a = 5;
    // check the memory address
    printf("memory address = %d\n", &a); /* wrong */
    printf("memory address = %u\n", &a); /* wrong */
    printf("memory address = %p\n", (void*)&a); /* right */
}

The request was aborted: Could not create SSL/TLS secure channel

From @sameerfair comment

"For .Net v4.0 I noticed, setting the value of ServicePointManager.SecurityProtocol to (SecurityProtocolType)3072 but before creating the HttpWebRequest object helped."

The above suggestion worked for me. Below are my code lines which are worked for me

var securedwebserviceurl="https://somedomain.com/service";
ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11;
// Skip validation of SSL/TLS certificate
ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
var httpWebRequest = (HttpWebRequest)WebRequest.Create(securedwebserviceurl);
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "POST";
httpWebRequest.ProtocolVersion= HttpVersion.Version10;
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream())) {
string responseFromServer = streamReader.ReadToEnd();
}

CAML query with nested ANDs and ORs for multiple fields

Since you are not allowed to put more than two conditions in one condition group (And | Or) you have to create an extra nested group (MSDN). The expression A AND B AND C looks like this:

<And>
    A
    <And>
        B
        C
    </And>
</And>

Your SQL like sample translated to CAML (hopefully with matching XML tags ;) ):

<Where>
    <And>
        <Or>
            <Eq>
                <FieldRef Name='FirstName' />
                <Value Type='Text'>John</Value>
            </Eq>
            <Or>
                <Eq>
                    <FieldRef Name='LastName' />
                    <Value Type='Text'>John</Value>
                </Eq>
                <Eq>
                    <FieldRef Name='Profile' />
                    <Value Type='Text'>John</Value>
                </Eq>
            </Or>
        </Or>
        <And>       
            <Or>
                <Eq>
                    <FieldRef Name='FirstName' />
                    <Value Type='Text'>Doe</Value>
                </Eq>
                <Or>
                    <Eq>
                        <FieldRef Name='LastName' />
                        <Value Type='Text'>Doe</Value>
                    </Eq>
                    <Eq>
                        <FieldRef Name='Profile' />
                        <Value Type='Text'>Doe</Value>
                    </Eq>
                </Or>
            </Or>
            <Or>
                <Eq>
                    <FieldRef Name='FirstName' />
                    <Value Type='Text'>123</Value>
                </Eq>
                <Or>
                    <Eq>
                        <FieldRef Name='LastName' />
                        <Value Type='Text'>123</Value>
                    </Eq>
                    <Eq>
                        <FieldRef Name='Profile' />
                        <Value Type='Text'>123</Value>
                    </Eq>
                </Or>
            </Or>
        </And>
    </And>
</Where>

When should I use nil and NULL in Objective-C?

nil means absence of value while NULL represent No Object,

NSArray *array = @[@"Hello World !", @101,[NSNULL null] ];

Here [NSNULL null] is an object which means no object, at the same time you cannot add nil to indicate absence of object.

you can use both nil and [NSNUll null] for checking too.

How do you plot bar charts in gnuplot?

I would just like to expand upon the top answer, which uses GNUPlot to create a bar graph, for absolute beginners because I read the answer and was still confused from the deluge of syntax.

We begin by writing a text file of GNUplot commands. Lets call it commands.txt:

set term png
set output "graph.png"
set boxwidth 0.5
set style fill solid
plot "data.dat" using 1:3:xtic(2) with boxes

set term png will set GNUplot to output a .png file and set output "graph.png" is the name of the file it will output to.

The next two lines are rather self explanatory. The fifth line contains a lot of syntax.

plot "data.dat" using 1:3:xtic(2) with boxes

"data.dat" is the data file we are operating on. 1:3 indicates we will be using column 1 of data.dat for the x-coordinates and column 3 of data.dat for the y-coordinates. xtic() is a function that is responsible for numbering/labeling the x-axis. xtic(2), therefore, indicates that we will be using column 2 of data.dat for labels.

"data.dat" looks like this:

0 label       100
1 label2      450
2 "bar label" 75

To plot the graph, enter gnuplot commands.txt in terminal.

Reading and writing to serial port in C on Linux

I've solved my problems, so I post here the correct code in case someone needs similar stuff.

Open Port

int USB = open( "/dev/ttyUSB0", O_RDWR| O_NOCTTY );

Set parameters

struct termios tty;
struct termios tty_old;
memset (&tty, 0, sizeof tty);

/* Error Handling */
if ( tcgetattr ( USB, &tty ) != 0 ) {
   std::cout << "Error " << errno << " from tcgetattr: " << strerror(errno) << std::endl;
}

/* Save old tty parameters */
tty_old = tty;

/* Set Baud Rate */
cfsetospeed (&tty, (speed_t)B9600);
cfsetispeed (&tty, (speed_t)B9600);

/* Setting other Port Stuff */
tty.c_cflag     &=  ~PARENB;            // Make 8n1
tty.c_cflag     &=  ~CSTOPB;
tty.c_cflag     &=  ~CSIZE;
tty.c_cflag     |=  CS8;

tty.c_cflag     &=  ~CRTSCTS;           // no flow control
tty.c_cc[VMIN]   =  1;                  // read doesn't block
tty.c_cc[VTIME]  =  5;                  // 0.5 seconds read timeout
tty.c_cflag     |=  CREAD | CLOCAL;     // turn on READ & ignore ctrl lines

/* Make raw */
cfmakeraw(&tty);

/* Flush Port, then applies attributes */
tcflush( USB, TCIFLUSH );
if ( tcsetattr ( USB, TCSANOW, &tty ) != 0) {
   std::cout << "Error " << errno << " from tcsetattr" << std::endl;
}

Write

unsigned char cmd[] = "INIT \r";
int n_written = 0,
    spot = 0;

do {
    n_written = write( USB, &cmd[spot], 1 );
    spot += n_written;
} while (cmd[spot-1] != '\r' && n_written > 0);

It was definitely not necessary to write byte per byte, also int n_written = write( USB, cmd, sizeof(cmd) -1) worked fine.

At last, read:

int n = 0,
    spot = 0;
char buf = '\0';

/* Whole response*/
char response[1024];
memset(response, '\0', sizeof response);

do {
    n = read( USB, &buf, 1 );
    sprintf( &response[spot], "%c", buf );
    spot += n;
} while( buf != '\r' && n > 0);

if (n < 0) {
    std::cout << "Error reading: " << strerror(errno) << std::endl;
}
else if (n == 0) {
    std::cout << "Read nothing!" << std::endl;
}
else {
    std::cout << "Response: " << response << std::endl;
}

This one worked for me. Thank you all!

Cannot find module cv2 when using OpenCV

This happens when python cannot refer to your default site-packages folder where you have kept the required python files or libraries

Add these lines in the code:

import sys

sys.path.append('/usr/local/lib/python2.7/site-packages')

or before running the python command in bash move to /usr/local/lib/python2.7/site-packages directory. This is a work around if you don't want to add any thing to the code.

Is either GET or POST more secure than the other?

This isn't security related but... browsers doesn't cache POST requests.

c++ integer->std::string conversion. Simple function?

Like mentioned earlier, I'd recommend boost lexical_cast. Not only does it have a fairly nice syntax:

#include <boost/lexical_cast.hpp>
std::string s = boost::lexical_cast<std::string>(i);

it also provides some safety:

try{
  std::string s = boost::lexical_cast<std::string>(i);
}catch(boost::bad_lexical_cast &){
 ...
}

What is IPV6 for localhost and 0.0.0.0?

Just for the sake of completeness: there are IPv4-mapped IPv6 addresses, where you can embed an IPv4 address in an IPv6 address (may not be supported by every IPv6 equipment).

Example: I run a server on my machine, which can be accessed via http://127.0.0.1:19983/solr. If I access it via an IPv4-mapped IPv6 address then I access it via http://[::ffff:127.0.0.1]:19983/solr (which will be converted to http://[::ffff:7f00:1]:19983/solr)

What should be in my .gitignore for an Android Studio project?

.gitignore from AndroidRate library

# Copyright 2017 - 2018 Vorlonsoft LLC
#
# Licensed under The MIT License (MIT)

# Built application files
*.ap_
*.apk

# Built library files
*.aar
*.jar

# Built native files
*.o
*.so

# Files for the Dalvik/Android Runtime (ART)
*.dex
*.odex

# Java class files
*.class

# Generated files
bin/
gen/
out/

# Gradle files
.gradle/
build/

# Local configuration file (sdk/ndk path, etc)
local.properties

# Windows thumbnail cache
Thumbs.db

# macOS
.DS_Store/

# Log Files
*.log

# Android Studio
.navigation/
captures/
output.json

# NDK
.externalNativeBuild/
obj/

# IntelliJ
## User-specific stuff
.idea/**/tasks.xml
.idea/**/workspace.xml
.idea/dictionaries
## Sensitive or high-churn files
.idea/**/dataSources/
.idea/**/dataSources.ids
.idea/**/dataSources.local.xml
.idea/**/dynamic.xml
.idea/**/sqlDataSources.xml
.idea/**/uiDesigner.xml
## Gradle
.idea/**/gradle.xml
.idea/**/libraries
## VCS
.idea/vcs.xml
## Module files
*.iml
## File-based project format
*.iws

sorting a vector of structs

As others have mentioned, you could use a comparison function, but you can also overload the < operator and the default less<T> functor will work as well:

struct data {
    string word;
    int number;
    bool operator < (const data& rhs) const {
        return word.size() < rhs.word.size();
    }
};

Then it's just:

std::sort(info.begin(), info.end());

Edit

As James McNellis pointed out, sort does not actually use the less<T> functor by default. However, the rest of the statement that the less<T> functor will work as well is still correct, which means that if you wanted to put struct datas into a std::map or std::set this would still work, but the other answers which provide a comparison function would need additional code to work with either.

How to auto-remove trailing whitespace in Eclipse?

As @Malvineous said, It's not professional but a work-around to use the Find/Replace method to remove trailing space (below including tab U+0009 and whitespace U+0020).
Just press Ctrl + F (or command + F)

  1. Find [\t ][\t ]*$
  2. Replace with blank string
  3. Use Regular expressions
  4. Replace All

extra:
For removing leading space, find ^[\t ][\t ]* instead of [\t ][\t ]*$
For removing blank lines, find ^\s*$\r?\n

Django -- Template tag in {% if %} block

You try this.

I have already tried it in my django template.

It will work fine. Just remove the curly braces pair {{ and }} from {{source}}.

I have also added <table> tag and that's it.

After modification your code will look something like below.

{% for source in sources %}
   <table>
      <tr>
          <td>{{ source }}</td>
          <td>
              {% if title == source %}
                Just now! 
              {% endif %}
          </td>
      </tr>
   </table>
{% endfor %}

My dictionary looks like below,

{'title':"Rishikesh", 'sources':["Hemkesh", "Malinikesh", "Rishikesh", "Sandeep", "Darshan", "Veeru", "Shwetabh"]}

and OUTPUT looked like below once my template got rendered.

Hemkesh 
Malinikesh  
Rishikesh   Just now!
Sandeep 
Darshan 
Veeru   
Shwetabh    

Does Python have a ternary conditional operator?

if variable is defined and you want to check if it has value you can just a or b

def test(myvar=None):
    # shorter than: print myvar if myvar else "no Input"
    print myvar or "no Input"

test()
test([])
test(False)
test('hello')
test(['Hello'])
test(True)

will output

no Input
no Input
no Input
hello
['Hello']
True

How to add comments into a Xaml file in WPF?

For anyone learning this stuff, comments are more important, so drawing on Xak Tacit's idea
(from User500099's link) for Single Property comments, add this to the top of the XAML code block:

<!--Comments Allowed With Markup Compatibility (mc) In XAML!
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:ØignoreØ="http://www.galasoft.ch/ignore"
    mc:Ignorable="ØignoreØ"
    Usage in property:
ØignoreØ:AttributeToIgnore="Text Of AttributeToIgnore"-->

Then in the code block

<Application FooApp:Class="Foo.App"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:ØignoreØ="http://www.galasoft.ch/ignore"
mc:Ignorable="ØignoreØ"
...

AttributeNotToIgnore="TextNotToIgnore"
...

...
ØignoreØ:IgnoreThisAttribute="IgnoreThatText"
...   
>
</Application>

Hidden features of Windows batch files

Redirecting output to the console, even if the batch's output is already redirected to a file via the > con syntax.

Example: foo.cmd:

echo a
echo b > con

Calling:

foo.cmd > output.txt

This will result in "a" going to output.txt yet "b" going to the console.

How to reset Jenkins security settings from the command line?

Using bcrypt you can solve this issue. Extending the @Reem answer for someone who is trying to automate the process using bash and python.

#!/bin/bash

pip install bcrypt
yum install -y https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum -y install xmlstarlet

cat > /tmp/jenkinsHash.py <<EOF
import bcrypt
import sys

if not sys.argv[1]:
  sys.exit(10)

plaintext_pwd=sys.argv[1]
encrypted_pwd=bcrypt.hashpw(sys.argv[1], bcrypt.gensalt(rounds=10, prefix=b"2a"))
isCorrect=bcrypt.checkpw(plaintext_pwd, encrypted_pwd)

if not isCorrect:
   sys.exit(20);

print "{}".format(encrypted_pwd)
EOF

chmod +x /tmp/jenkinsHash.py
cd /var/lib/jenkins/users/admin*
pwd
while (( 1 )); do
    echo "Waiting for Jenkins to generate admin user's config file ..."

    if [[ -f "./config.xml" ]]; then
        break
    fi

    sleep 10
done

echo "Admin config file created"

admin_password=$(python /tmp/jenkinsHash.py password 2>&1)

# Repalcing the new passowrd
xmlstarlet -q ed --inplace -u "/user/properties/hudson.security.HudsonPrivateSecurityRealm_-Details/passwordHash" -v '#jbcrypt:'"$admin_password" config.xml

# Restart
systemctl restart jenkins
sleep 10

I have kept password hardcoded here but it can be a user input depending upon the requirement. Also make sure to add that sleep otherwise any other command revolving around Jenkins will fail.

Drop view if exists

Regarding the error

'CREATE VIEW' must be the first statement in a query batch.

Microsoft SQL Server has a quirky reqirement that CREATE VIEW be the only statement in a batch. This is also true of a few other statements, such as CREATE FUNCTION. It is not true of CREATE TABLE, so go figure …

The solution is to send your script to the server in small batches. One way to do this is to select a single statement and execute it. This is clearly inconvenient.

The more convenient solution is to get the client to send the script in small isolated batches.

The GO keyword is not strictly an SQL command, which is why you can’t end it with a semicolon like real SQL commands. Instead it is an instruction to the client to break the script at this point and to send the portion as a batch.

As a result, you end up writing something like:

DROP VIEW IF EXISTS … ;
GO
CREATE VIEW … AS … ;
GO

None of the other database servers I have encountered (PostgreSQL, MySQL, Oracle, SQLite) have this quirk, so the requirement appears to be Microsoft Only.

DeprecationWarning: Buffer() is deprecated due to security and usability issues when I move my script to another server

var userPasswordString = new Buffer(baseAuth, 'base64').toString('ascii');

Change this line from your code to this -

var userPasswordString = Buffer.from(baseAuth, 'base64').toString('ascii');

or in my case, I gave the encoding in reverse order

var userPasswordString = Buffer.from(baseAuth, 'utf-8').toString('base64');

Spring Data JPA Update @Query not updating?

I was able to get this to work. I will describe my application and the integration test here.

The Example Application

The example application has two classes and one interface that are relevant to this problem:

  1. The application context configuration class
  2. The entity class
  3. The repository interface

These classes and the repository interface are described in the following.

The source code of the PersistenceContext class looks as follows:

import com.jolbox.bonecp.BoneCPDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;
import java.util.Properties;

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "net.petrikainulainen.spring.datajpa.todo.repository")
@PropertySource("classpath:application.properties")
public class PersistenceContext {

    protected static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";
    protected static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";
    protected static final String PROPERTY_NAME_DATABASE_URL = "db.url";
    protected static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";

    private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";
    private static final String PROPERTY_NAME_HIBERNATE_FORMAT_SQL = "hibernate.format_sql";
    private static final String PROPERTY_NAME_HIBERNATE_HBM2DDL_AUTO = "hibernate.hbm2ddl.auto";
    private static final String PROPERTY_NAME_HIBERNATE_NAMING_STRATEGY = "hibernate.ejb.naming_strategy";
    private static final String PROPERTY_NAME_HIBERNATE_SHOW_SQL = "hibernate.show_sql";

    private static final String PROPERTY_PACKAGES_TO_SCAN = "net.petrikainulainen.spring.datajpa.todo.model";

    @Autowired
    private Environment environment;

    @Bean
    public DataSource dataSource() {
        BoneCPDataSource dataSource = new BoneCPDataSource();

        dataSource.setDriverClass(environment.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
        dataSource.setJdbcUrl(environment.getRequiredProperty(PROPERTY_NAME_DATABASE_URL));
        dataSource.setUsername(environment.getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));
        dataSource.setPassword(environment.getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));

        return dataSource;
    }

    @Bean
    public JpaTransactionManager transactionManager() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();

        transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());

        return transactionManager;
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();

        entityManagerFactoryBean.setDataSource(dataSource());
        entityManagerFactoryBean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
        entityManagerFactoryBean.setPackagesToScan(PROPERTY_PACKAGES_TO_SCAN);

        Properties jpaProperties = new Properties();
        jpaProperties.put(PROPERTY_NAME_HIBERNATE_DIALECT, environment.getRequiredProperty(PROPERTY_NAME_HIBERNATE_DIALECT));
        jpaProperties.put(PROPERTY_NAME_HIBERNATE_FORMAT_SQL, environment.getRequiredProperty(PROPERTY_NAME_HIBERNATE_FORMAT_SQL));
        jpaProperties.put(PROPERTY_NAME_HIBERNATE_HBM2DDL_AUTO, environment.getRequiredProperty(PROPERTY_NAME_HIBERNATE_HBM2DDL_AUTO));
        jpaProperties.put(PROPERTY_NAME_HIBERNATE_NAMING_STRATEGY, environment.getRequiredProperty(PROPERTY_NAME_HIBERNATE_NAMING_STRATEGY));
        jpaProperties.put(PROPERTY_NAME_HIBERNATE_SHOW_SQL, environment.getRequiredProperty(PROPERTY_NAME_HIBERNATE_SHOW_SQL));

        entityManagerFactoryBean.setJpaProperties(jpaProperties);

        return entityManagerFactoryBean;
    }
}

Let's assume that we have a simple entity called Todo which source code looks as follows:

@Entity
@Table(name="todos")
public class Todo {

    public static final int MAX_LENGTH_DESCRIPTION = 500;
    public static final int MAX_LENGTH_TITLE = 100;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "description", nullable = true, length = MAX_LENGTH_DESCRIPTION)
    private String description;

    @Column(name = "title", nullable = false, length = MAX_LENGTH_TITLE)
    private String title;

    @Version
    private long version;
}

Our repository interface has a single method called updateTitle() which updates the title of a todo entry. The source code of the TodoRepository interface looks as follows:

import net.petrikainulainen.spring.datajpa.todo.model.Todo;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

import java.util.List;

public interface TodoRepository extends JpaRepository<Todo, Long> {

    @Modifying
    @Query("Update Todo t SET t.title=:title WHERE t.id=:id")
    public void updateTitle(@Param("id") Long id, @Param("title") String title);
}

The updateTitle() method is not annotated with the @Transactional annotation because I think that it is best to use a service layer as a transaction boundary.

The Integration Test

The Integration Test uses DbUnit, Spring Test and Spring-Test-DBUnit. It has three components which are relevant to this problem:

  1. The DbUnit dataset which is used to initialize the database into a known state before the test is executed.
  2. The DbUnit dataset which is used to verify that the title of the entity is updated.
  3. The integration test.

These components are described with more details in the following.

The name of the DbUnit dataset file which is used to initialize the database to known state is toDoData.xml and its content looks as follows:

<dataset>
    <todos id="1" description="Lorem ipsum" title="Foo" version="0"/>
    <todos id="2" description="Lorem ipsum" title="Bar" version="0"/>
</dataset>

The name of the DbUnit dataset which is used to verify that the title of the todo entry is updated is called toDoData-update.xml and its content looks as follows (for some reason the version of the todo entry was not updated but the title was. Any ideas why?):

<dataset>
    <todos id="1" description="Lorem ipsum" title="FooBar" version="0"/>
    <todos id="2" description="Lorem ipsum" title="Bar" version="0"/>
</dataset>

The source code of the actual integration test looks as follows (Remember to annotate the test method with the @Transactional annotation):

import com.github.springtestdbunit.DbUnitTestExecutionListener;
import com.github.springtestdbunit.TransactionDbUnitTestExecutionListener;
import com.github.springtestdbunit.annotation.DatabaseSetup;
import com.github.springtestdbunit.annotation.ExpectedDatabase;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.TestExecutionListeners;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.support.DependencyInjectionTestExecutionListener;
import org.springframework.test.context.support.DirtiesContextTestExecutionListener;
import org.springframework.test.context.transaction.TransactionalTestExecutionListener;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {PersistenceContext.class})
@TestExecutionListeners({ DependencyInjectionTestExecutionListener.class,
        DirtiesContextTestExecutionListener.class,
        TransactionalTestExecutionListener.class,
        DbUnitTestExecutionListener.class })
@DatabaseSetup("todoData.xml")
public class ITTodoRepositoryTest {

    @Autowired
    private TodoRepository repository;

    @Test
    @Transactional
    @ExpectedDatabase("toDoData-update.xml")
    public void updateTitle_ShouldUpdateTitle() {
        repository.updateTitle(1L, "FooBar");
    }
}

After I run the integration test, the test passes and the title of the todo entry is updated. The only problem which I am having is that the version field is not updated. Any ideas why?

I undestand that this description is a bit vague. If you want to get more information about writing integration tests for Spring Data JPA repositories, you can read my blog post about it.

showDialog deprecated. What's the alternative?

To display dialog box, you can use the following code. This is to display a simple AlertDialog box with multiple check boxes:

AlertDialog.Builder alertDialog= new AlertDialog.Builder(MainActivity.this); .
            alertDialog.setTitle("this is a dialog box ");
            alertDialog.setPositiveButton("ok", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                    Toast.makeText(getBaseContext(),"ok ive wrote this 'ok' here" ,Toast.LENGTH_SHORT).show();

                }
            });
            alertDialog.setNegativeButton("cancel", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                        Toast.makeText(getBaseContext(), "cancel ' comment same as ok'", Toast.LENGTH_SHORT).show();


                }
            });
            alertDialog.setMultiChoiceItems(items, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                    // TODO Auto-generated method stub
                    Toast.makeText(getBaseContext(), items[which] +(isChecked?"clicked'again i've wrrten this click'":"unchecked"),Toast.LENGTH_SHORT).show();

                }
            });
            alertDialog.show();

Heading

Whereas if you are using the showDialog function to display different dialog box or anything as per the arguments passed, you can create a self function and can call it under the onClickListener() function. Something like:

 public CharSequence[] items={"google","Apple","Kaye"};
public boolean[] checkedItems=new boolean[items.length];
Button bt;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    bt=(Button) findViewById(R.id.bt);
    bt.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            display(0);             
        }       
    });
}

and add the code of dialog box given above in the function definition.

MySQL wait_timeout Variable - GLOBAL vs SESSION

SHOW SESSION VARIABLES LIKE "wait_timeout"; -- 28800
SHOW GLOBAL VARIABLES LIKE "wait_timeout"; -- 28800

At first, wait_timeout = 28800 which is the default value. To change the session value, you need to set the global variable because the session variable is read-only.

SET @@GLOBAL.wait_timeout=300

After you set the global variable, the session variable automatically grabs the value.

SHOW SESSION VARIABLES LIKE "wait_timeout"; -- 300
SHOW GLOBAL VARIABLES LIKE "wait_timeout"; -- 300

Next time when the server restarts, the session variables will be set to the default value i.e. 28800.

P.S. I m using MySQL 5.6.16

View HTTP headers in Google Chrome?

You can find the headers option in the Network tab in Developer's console in Chrome:

  1. In Chrome press F12 to open Developer's console.
  2. Select the Network tab. This tab gives you the information about the requests fired from the browser.
  3. Select a request by clicking on the request name. There you can find the Header information for that request along with some other information like Preview, Response and Timing.

Also, in my version of Chrome (50.0.2661.102), it gives an extension named LIVE HTTP Headers which gives information about the request headers for all the HTTP requests.

update: added image

enter image description here

Override back button to act like home button

if it helps someone else, I had an activity with 2 layouts that I toggled on and off for visibilty, trying to emulate a kind of page1 > page2 structure. if they were on page 2 and pressed the back button I wanted them to go back to page 1, if they pressed the back button on page 1 it should still work as normal. Its pretty basic but it works

@Override
public void onBackPressed() {
// check if page 2 is open
    RelativeLayout page2layout = (RelativeLayout)findViewById(R.id.page2layout);
    if(page2layout.getVisibility() == View.VISIBLE){
        togglePageLayout(); // my method to toggle the views
        return;
    }else{
        super.onBackPressed(); // allows standard use of backbutton for page 1
    }

}

hope it helps someone, cheers

In Matplotlib, what does the argument mean in fig.add_subplot(111)?

I think this would be best explained by the following picture:

enter image description here

To initialize the above, one would type:

import matplotlib.pyplot as plt
fig = plt.figure()
fig.add_subplot(221)   #top left
fig.add_subplot(222)   #top right
fig.add_subplot(223)   #bottom left
fig.add_subplot(224)   #bottom right 
plt.show()

COALESCE Function in TSQL

declare @store table (store_id varchar(300))
insert into @store 
values ('aa'),('bb'),('cc')
declare @str varchar (4000)
select @str = concat(@str+',',store_id) from @store
select @str

Can I pass an argument to a VBScript (vbs file launched with cscript)?

You can use WScript.Arguments to access the arguments passed to your script.

Calling the script:

cscript.exe test.vbs "C:\temp\"

Inside your script:

Set File = FSO.OpenTextFile(WScript.Arguments(0) &"\test.txt", 2, True)

Don't forget to check if there actually has been an argument passed to your script. You can do so by checking the Count property:

if WScript.Arguments.Count = 0 then
    WScript.Echo "Missing parameters"
end if

If your script is over after you close the file then there is no need to set the variables to Nothing. The resources will be cleaned up automatically when the cscript.exe process terminates. Setting a variable to Nothing usually is only necessary if you explicitly want to free resources during the execution of your script. In that case, you would set variables which contain a reference to a COM object to Nothing, which would release the COM object before your script terminates. This is just a short answer to your bonus question, you will find more information in these related questions:

Is there a need to set Objects to Nothing inside VBA Functions

When must I set a variable to “Nothing” in VB6?

How to get htaccess to work on MAMP

Go to httpd.conf on /Applications/MAMP/conf/apache and see if the LoadModule rewrite_module modules/mod_rewrite.so line is un-commented (without the # at the beginning)

and change these from ...

<VirtualHost *:80>
    ServerName ...
    DocumentRoot /....
</VirtualHost>

To this:

<VirtualHost *:80>
    ServerAdmin ...
    ServerName ...

    DocumentRoot ...
    <Directory ...>
        Options FollowSymLinks
        AllowOverride None
    </Directory>
    <Directory ...>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Order allow,deny
        allow from all
    </Directory>
</VirtualHost>

How to define a relative path in java

Firstly, see the different between absolute path and relative path here:

An absolute path always contains the root element and the complete directory list required to locate the file.

Alternatively, a relative path needs to be combined with another path in order to access a file.

In constructor File(String pathname), Javadoc's File class said that

A pathname, whether abstract or in string form, may be either absolute or relative.

If you want to get relative path, you must be define the path from the current working directory to file or directory.Try to use system properties to get this.As the pictures that you drew:

String localDir = System.getProperty("user.dir");
File file = new File(localDir + "\\config.properties");

Moreover, you should try to avoid using similar ".", "../", "/", and other similar relative to the file location relative path, because when files are moved, it is harder to handle.

Select unique values with 'select' function in 'dplyr' library

In dplyr 0.3 this can be easily achieved using the distinct() method.

Here is an example:

distinct_df = df %>% distinct(field1)

You can get a vector of the distinct values with:

distinct_vector = distinct_df$field1

You can also select a subset of columns at the same time as you perform the distinct() call, which can be cleaner to look at if you examine the data frame using head/tail/glimpse.:

distinct_df = df %>% distinct(field1) %>% select(field1) distinct_vector = distinct_df$field1

How to toggle a boolean?

If you don't mind the boolean being converted to a number (that is either 0 or 1), you can use the Bitwise XOR Assignment Operator. Like so:

bool ^= true;   //- toggle value.


This is especially good if you use long, descriptive boolean names, EG:

var inDynamicEditMode   = true;     // Value is: true (boolean)
inDynamicEditMode      ^= true;     // Value is: 0 (number)
inDynamicEditMode      ^= true;     // Value is: 1 (number)
inDynamicEditMode      ^= true;     // Value is: 0 (number)

This is easier for me to scan than repeating the variable in each line.

This method works in all (major) browsers (and most programming languages).

Could not install packages due to an EnvironmentError: [WinError 5] Access is denied:

TYPE CMD in search and when the command prompt appears in the BEST MATCH search result right-click on it and select 'Run as Administrator' when the user control window appears select 'Yes'. The command prompt window will appear and you should see "C:/WINDOWS/system32>"

at this point just type what you want, should work!

SQL Case Expression Syntax?

Sybase has the same case syntax as SQL Server:

Description

Supports conditional SQL expressions; can be used anywhere a value expression can be used.

Syntax

case 
     when search_condition then expression 
    [when search_condition then expression]...
    [else expression]
end

Case and values syntax

case expression
     when expression then expression 
    [when expression then expression]...
    [else expression]
end

Parameters

case

begins the case expression.

when

precedes the search condition or the expression to be compared.

search_condition

is used to set conditions for the results that are selected. Search conditions for case expressions are similar to the search conditions in a where clause. Search conditions are detailed in the Transact-SQL User’s Guide.

then

precedes the expression that specifies a result value of case.

expression

is a column name, a constant, a function, a subquery, or any combination of column names, constants, and functions connected by arithmetic or bitwise operators. For more information about expressions, see “Expressions” in.

Example

select disaster, 
       case
            when disaster = "earthquake" 
                then "stand in doorway"
            when disaster = "nuclear apocalypse" 
                then "hide in basement"
            when monster = "zombie apocalypse" 
                then "hide with Chuck Norris"
            else
                then "ask mom"
       end 
  from endoftheworld

Change the Arrow buttons in Slick slider

here is another example for changing the arrows and using your own arrow-images.

.slick-prev:before {
    background-image: url('images/arrow-left.png');
    background-size: 50px 50px;
    display: inline-block;
    width: 50px; 
    height: 50px;
    content:"";
}
.slick-next:before {
    background-image: url('images/arrow-right.png');
    background-size: 50px 50px;
    display: inline-block;
    width: 50px; 
    height: 50px;
    content:"";
}

Send data from activity to fragment in Android

From Activity you send data with Bundle as:

Bundle bundle = new Bundle();
bundle.putString("data", "Data you want to send");

// Your fragment
MyFragment obj = new MyFragment();
obj.setArguments(bundle);

And in Fragment onCreateView method get the data:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
{
    String data = getArguments().getString("data");// data which sent from activity  
    return inflater.inflate(R.layout.myfragment, container, false);
}

Get item in the list in Scala?

Safer is to use lift so you can extract the value if it exists and fail gracefully if it does not.

data.lift(2)

This will return None if the list isn't long enough to provide that element, and Some(value) if it is.

scala> val l = List("a", "b", "c")
scala> l.lift(1)
Some("b")
scala> l.lift(5)
None

Whenever you're performing an operation that may fail in this way it's great to use an Option and get the type system to help make sure you are handling the case where the element doesn't exist.

Explanation:

This works because List's apply (which sugars to just parentheses, e.g. l(index)) is like a partial function that is defined wherever the list has an element. The List.lift method turns the partial apply function (a function that is only defined for some inputs) into a normal function (defined for any input) by basically wrapping the result in an Option.

What is the equivalent of "none" in django templates?

You can also use the built-in template filter default:

If value evaluates to False (e.g. None, an empty string, 0, False); the default "--" is displayed.

{{ profile.user.first_name|default:"--" }}

Documentation: https://docs.djangoproject.com/en/dev/ref/templates/builtins/#default

Android Service needs to run always (Never pause or stop)

I had overcome this issue, and my sample code is as follows.

Add the below line in your Main Activity, here BackGroundClass is the service class.You can create this class in New -> JavaClass (In this class, add the process (tasks) in which you needs to occur at background). For Convenience, first denote them with notification ringtone as background process.

 startService(new Intent(this, BackGroundClass .class));

In the BackGroundClass, just include my codings and you may see the result.

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.provider.Settings;
import android.support.annotation.Nullable;
import android.widget.Toast;

public class BackgroundService  extends Service {
    private MediaPlayer player;
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
@Override
    public int onStartCommand(Intent intent, int flags, int startId) {
     player = MediaPlayer.create(this,Settings.System.DEFAULT_RINGTONE_URI);
        player.setLooping(true);
         player.start();
        return START_STICKY;
    }
 @Override
    public void onDestroy() {
        super.onDestroy();
         player.stop();
    }
}

And in AndroidManifest.xml, try to add this.

<service android:name=".BackgroundService"/>

Run the program, just open the application, you may find the notification alert at the background. Even, you may exit the application but still you might have hear the ringtone alert unless and until if you switched off the application or Uninstall the application. This denotes that the notification alert is at the background process. Like this you may add some process for background.

Kind Attention: Please, Don't verify with TOAST as it will run only once even though it was at background process.

Hope it will helps...!!

How to escape a JSON string containing newline characters using JavaScript?

As per user667073 suggested, except reordering the backslash replacement first, and fixing the quote replacement

escape = function (str) {
  return str
    .replace(/[\\]/g, '\\\\')
    .replace(/[\"]/g, '\\\"')
    .replace(/[\/]/g, '\\/')
    .replace(/[\b]/g, '\\b')
    .replace(/[\f]/g, '\\f')
    .replace(/[\n]/g, '\\n')
    .replace(/[\r]/g, '\\r')
    .replace(/[\t]/g, '\\t');
};

SEVERE: ContainerBase.addChild: start:org.apache.catalina.LifecycleException: Failed to start error

My reason was having same library with different snapshot versions in WEB-INF/lib:

some-lib-3.14.0.143-SNAPSHOT.jar
some-lib-3.14.0.143-20200708.101204-1.jar

To fix the issue remove redundant copy.

How to use variables in SQL statement in Python?

http://www.amk.ca/python/writing/DB-API.html

Be careful when you simply append values of variables to your statements: Imagine a user naming himself ';DROP TABLE Users;' -- That's why you need to use sql escaping, which Python provides for you when you use the cursor.execute in a decent manner. Example in the url is:

cursor.execute("insert into Attendees values (?, ?, ?)", (name,
seminar, paid) )

Display filename before matching line

How about this, which I managed to achieve thanks, in part, to this post.

You want to find several files, lets say logs with different names but a pattern (e.g. filename=logfile.DATE), inside several directories with a pattern (e.g. /logsapp1, /logsapp2). Each file has a pattern you want to grep (e.g. "init time"), and you want to have the "init time" of each file, but knowing which file it belongs to.

find ./logsapp* -name logfile* | xargs -I{} grep "init time" {} \dev\null | tee outputfilename.txt

Then the outputfilename.txt would be something like

./logsapp1/logfile.22102015: init time: 10ms
./logsapp1/logfile.21102015: init time: 15ms
./logsapp2/logfile.21102015: init time: 17ms
./logsapp2/logfile.22102015: init time: 11ms

In general

find ./path_pattern/to_files* -name filename_pattern* | xargs -I{} grep "grep_pattern" {} \dev\null | tee outfilename.txt

Explanation:

find command will search the filenames based in the pattern

then, pipe xargs -I{} will redirect the find output to the {}

which will be the input for grep ""pattern" {}

Then the trick to make grep display the filenames \dev\null

and finally, write the output in file with tee outputfile.txt

This worked for me in grep version 9.0.5 build 1989.

SQL: Alias Column Name for Use in CASE Statement

make it so easy.

select columnnameshow = (CASE tipoventa
when 'CONTADO' then 'contadito'
when 'CREDITO' then 'cred'
else 'no result'
end) from Promocion.Promocion 

How do I make a transparent border with CSS?

Since you said in a comment that the more options you have, the better, here's another one.

In CSS3, there are two different so-called "box models". One adds the border and padding to the width of a block element, while the other does not. You can use the latter by specifying

-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
-ms-box-sizing: border-box;
box-sizing: border-box;

Then, in modern browsers, the element will always have the same width. I.e., if you apply a border to it on hover, the width of the border will not add to the overall width of the element; the border will be added "inside" the element, so to speak. However, if I remember correctly, you must specify the width explicitly for this to work. Which is probably not an option for you in this particular case, but you can keep it in mind for future situations.

How do I use a 32-bit ODBC driver on 64-bit Server 2008 when the installer doesn't create a standard DSN?

It turns out that you can create 32-bit ODBC connections using C:\Windows\SysWOW64\odbcad32.exe. My solution was to create the 32-bit ODBC connection as a System DSN. This still didn't allow me to connect to it since .NET couldn't look it up. After significant and fruitless searching to find how to get the OdbcConnection class to look for the DSN in the right place, I stumbled upon a web site that suggested modifying the registry to solve a different problem.

I ended up creating the ODBC connection directly under HKLM\Software\ODBC. I looked in the SysWOW6432 key to find the parameters that were set up using the 32-bit version of the ODBC administration tool and recreated this in the standard location. I didn't add an entry for the driver, however, as that was not installed by the standard installer for the app either.

After creating the entry (by hand), I fired up my windows service and everything was happy.

PHP: Call to undefined function: simplexml_load_string()

I think it can be something like in this Post: Class 'SimpleXMLElement' not found on puphpet PHP 5.6 So maybe you could install/activate

php-xml or php-simplexml

Do not forget to activate the libraries in the php.ini file. (like the top comment)

Build not visible in itunes connect

When you upload your build from Application loader or directly from your xcode to App Store and it is not showing even on multiple uploads with different build version then

  1. Open your .plist file and check whether there is any key string starting with "Privacy - ........."
  2. If that key string value is empty, then Add some string.
    example, for me i was using camera, photo Library, Microphone and Location.
    For my project i added the string as follows
    a. This app requires access to the Camera.
    b. This app requires access to the Photo Library.
    c. This app requires access to Microphone of your device.
    d. This app requires access to your Location.
    e. This app requires access to the Bluetooth.
  3. Now upload the build it will get Accepted.

Note: This permission string is mandatory from iOS 10.

View markdown files offline

pandoc is a nice Text-To-Text conversion tool that solves the problem of offline visualization of your Markdown. Just issue:

pandoc -f markdown -t html README.md > README.html

Dark Theme for Visual Studio 2010 With Productivity Power Tools

You can also try this handy online tool, which generates .vssettings file for you.

Visual Studio Color Theme Generator

How do I fix a .NET windows application crashing at startup with Exception code: 0xE0434352?

I'm not sure if this will help anyone or not, but since it was my problem, I figure it's worth mentioning:

I was getting this error, and it turned out to be a problem with the platform for which the EXE was built. We had it building for x86, and it needed to be x64, because of an Oracle reference in the project. When we made that change, the problem went away. So, see if you have any similar conflicts.

Java Mouse Event Right Click

I've seen

anEvent.isPopupTrigger() 

be used before. I'm fairly new to Java so I'm happy to hear thoughts about this approach :)

'printf' vs. 'cout' in C++

For me, the real differences which would make me go for 'cout' rather than 'printf' are:

1) << operator can be overloaded for my classes.

2) Output stream for cout can be easily changed to a file : (: copy paste :)

#include <iostream>
#include <fstream>
using namespace std;

int main ()
{
    cout << "This is sent to prompt" << endl;
    ofstream file;
    file.open ("test.txt");
    streambuf* sbuf = cout.rdbuf();
    cout.rdbuf(file.rdbuf());
    cout << "This is sent to file" << endl;
    cout.rdbuf(sbuf);
    cout << "This is also sent to prompt" << endl;
    return 0;
}

3) I find cout more readable, especially when we have many parameters.

One problem with cout is the formatting options. Formatting the data (precision, justificaton, etc.) in printf is easier.

Regular Expression with wildcards to match any character

The following should work:

ABC: *\([a-zA-Z]+\) *(.+)

Explanation:

ABC:            # match literal characters 'ABC:'
 *              # zero or more spaces
\([a-zA-Z]+\)   # one or more letters inside of parentheses
 *              # zero or more spaces
(.+)            # capture one or more of any character (except newlines)

To get your desired grouping based on the comments below, you can use the following:

(ABC:) *(\([a-zA-Z]+\).+)

Map vs Object in JavaScript

One aspect of the Map that is not given much press here is lookup. According to the spec:

A Map object must be implemented using either hash tables or other mechanisms that, on average, provide access times that are sublinear on the number of elements in the collection. The data structures used in this Map objects specification is only intended to describe the required observable semantics of Map objects. It is not intended to be a viable implementation model.

For collections that have a huge number of items and require item lookups, this is a huge performance boost.

TL;DR - Object lookup is not specified, so it can be on order of the number of elements in the object, i.e., O(n). Map lookup must use a hash table or similar, so Map lookup is the same regardless of Map size, i.e. O(1).

How to choose multiple files using File Upload Control?

here is the complete example of how you can select and upload multiple files in asp.net using file upload control....

write this code in .aspx file..

<head runat="server">
    <title></title>
</head>
<body>
<form id="form1" runat="server" enctype="multipart/form-data">
<div>
    <input type="file" id="myfile" multiple="multiple" name="myfile" runat="server" size="100" />
    <br />
    <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
    <br />
    <asp:Label ID="Span1" runat="server"></asp:Label>
</div>
</form>
</body>
</html>

after that write this code in .aspx.cs file..

   protected void Button1_Click(object sender,EventArgs e) {
          string filepath = Server.MapPath("\\Upload");
          HttpFileCollection uploadedFiles = Request.Files;
          Span1.Text = string.Empty;

          for(int i = 0;i < uploadedFiles.Count;i++) {
              HttpPostedFile userPostedFile = uploadedFiles[i];

              try {
                  if (userPostedFile.ContentLength > 0) {
                     Span1.Text += "<u>File #" + (i + 1) +  "</u><br>";
                     Span1.Text += "File Content Type: " +  userPostedFile.ContentType      + "<br>";
                     Span1.Text += "File Size: " + userPostedFile.ContentLength           + "kb<br>";
                     Span1.Text += "File Name: " + userPostedFile.FileName + "<br>";

                     userPostedFile.SaveAs(filepath + "\\" +    Path.GetFileName(userPostedFile.FileName));                  
                     Span1.Text += "Location where saved: " +   filepath + "\\" +   Path.GetFileName(userPostedFile.FileName) + "<p>";
                  }
              } catch(Exception Ex) {
                  Span1.Text += "Error: <br>" + Ex.Message;
              }
           }
        }
    }

and here you go...your multiple file upload control is ready..have a happy day.

To get specific part of a string in c#

You can use Substring:

string b = a.Substring(0,3);

In what cases will HTTP_REFERER be empty

I have found the browser referer implementation to be really inconsistent.

For example, an anchor element with the "download" attribute works as expected in Safari and sends the referer, but in Chrome the referer will be empty or "-" in the web server logs.

<a href="http://foo.com/foo" download="bar">click to download</a>

Is broken in Chrome - no referer sent.

Add one day to date in javascript

use this i think it is useful for you

var endDate=startDate.setDate(startDate.getDate() + 1);

Fill remaining vertical space - only CSS

you need javascript and some client side calculations: http://jsfiddle.net/omegaiori/NERE8/2/

you will need jquery to effectively achieve what you want. this function is very simple but very effective:

(function () {


    var heights = $("#wrapper").outerHeight(true);
    var outerHeights = $("#first").outerHeight(true);
    jQuery('#second').css('height', (heights - outerHeights) + "px");

})();

first it detects the wrapper height, as it is set to 100% it's different everytime (it depends on what screen you are landing). in the second step it gives the #second div the appropriate height subtracting from the wrapper height the #first div height. the result is the available height left in the wrapper div

Apache Maven install "'mvn' not recognized as an internal or external command" after setting OS environmental variables?

As others have done, creating new System variables M2 and M2_HOME solved the problem. Just making User variables M2 and M2_HOME on my Windows XP machine led to maven not being recognised from the command line. I then deleted the User variables, created copies as System variables and it all came to life.

This was apache-maven-3.0.4 with XP sp3. So the instructions in: http://maven.apache.org/download.cgi seem incorrect.

How to split one text file into multiple *.txt files?

You can use the linux bash core utility split

split -b 1M -d  file.txt file 

Note that M or MB both are OK but size is different. MB is 1000 * 1000, M is 1024^2

If you want to separate by lines you can use -l parameter.

UPDATE

a=(`wc -l yourfile`) ; lines=`echo $(($a/12)) | bc -l` ; split -l $lines -d  file.txt file

Another solution as suggested by Kirill, you can do something like the following

split -n l/12 file.txt

Note that is l not one, split -n has a few options, like N, k/N, l/k/N, r/N, r/k/N.

Where does VBA Debug.Print log to?

Where do you want to see the output?

Messages being output via Debug.Print will be displayed in the immediate window which you can open by pressing Ctrl+G.

You can also Activate the so called Immediate Window by clicking View -> Immediate Window on the VBE toolbar

enter image description here

C++ float array initialization

No, it sets all members/elements that haven't been explicitly set to their default-initialisation value, which is zero for numeric types.

Vertical align text in block element

Would using padding be OK for your needs?: http://jsfiddle.net/sm8jy/:

li {
    background: red;
    text-align:center;
}
li a {
    padding: 4em 0;
    display: block;
}

Declaring and using MySQL varchar variables

I ran into the same problem using MySQL Workbench. According to the MySQL documentation, the DECLARE "statement declares local variables within stored programs." That apparently means it is only guaranteed to work with stored procedures/functions.

The solution for me was to simply remove the DECLARE statement, and introduce the variable in the SET statement. For your code that would mean:

-- DECLARE FOO varchar(7); 
-- DECLARE oldFOO varchar(7);

-- the @ symbol is required
SET @FOO = '138'; 
SET @oldFOO = CONCAT('0', FOO);

UPDATE mypermits SET person = FOO WHERE person = oldFOO;

How to remove leading and trailing zeros in a string? Python

What about a basic

your_string.strip("0")

to remove both trailing and leading zeros ? If you're only interested in removing trailing zeros, use .rstrip instead (and .lstrip for only the leading ones).

More info in the doc.

You could use some list comprehension to get the sequences you want like so:

trailing_removed = [s.rstrip("0") for s in listOfNum]
leading_removed = [s.lstrip("0") for s in listOfNum]
both_removed = [s.strip("0") for s in listOfNum]

How to allow access outside localhost

For the problem was Firewall. If you are on Windows, make sure node is allowed through enter image description here

Is there a command to list all Unix group names?

If you want all groups known to the system, I would recommend using getent group instead of parsing /etc/group:

getent group

The reason is that on networked systems, groups may not only read from /etc/group file, but also obtained through LDAP or Yellow Pages (the list of known groups comes from the local group file plus groups received via LDAP or YP in these cases).

If you want just the group names you can use:

getent group | cut -d: -f1

I am getting an "Invalid Host header" message when connecting to webpack-dev-server remotely

If you are running webpack-dev-server in a container and are sending requests to it via its container name, you will get this error. To allow requests from other containers on the same network, simply provide the container name (or whatever name is used to resolve the container) using the --public option. This is better than disabling the security check entirely.

In my case, I was running webpack-dev-server in a container named assets with docker-compose. I changed the start command to this:

webpack-dev-server --mode development --host 0.0.0.0 --public assets

And the other container was now able to make requests via http://assets:5000.

Display all dataframe columns in a Jupyter Python Notebook

If you want to show all the rows set like bellow

pd.options.display.max_rows = None

If you want to show all columns set like bellow

pd.options.display.max_columns = None

auto run a bat script in windows 7 at login

To run the batch file when the VM user logs in:

Drag the shortcut--the one that's currently on your desktop--(or the batch file itself) to Start - All Programs - Startup. Now when you login as that user, it will launch the batch file.

Another way to do the same thing is to save the shortcut or the batch file in %AppData%\Microsoft\Windows\Start Menu\Programs\Startup\.

As far as getting it to run full screen, it depends a bit what you mean. You can have it launch maximized by editing your batch file like this:

start "" /max "C:\Program Files\Oracle\VirtualBox\VirtualBox.exe" --comment "VM" --startvm "12dada4d-9cfd-4aa7-8353-20b4e455b3fa"

But if VirtualBox has a truly full-screen mode (where it hides even the taskbar), you'll have to look for a command-line parameter on VirtualBox.exe. I'm not familiar with that product.

javascript function wait until another function to finish

In my opinion, deferreds/promises (as you have mentionned) is the way to go, rather than using timeouts.

Here is an example I have just written to demonstrate how you could do it using deferreds/promises.

Take some time to play around with deferreds. Once you really understand them, it becomes very easy to perform asynchronous tasks.

Hope this helps!

$(function(){
    function1().done(function(){
        // function1 is done, we can now call function2
        console.log('function1 is done!');

        function2().done(function(){
            //function2 is done
            console.log('function2 is done!');
        });
    });
});

function function1(){
    var dfrd1 = $.Deferred();
    var dfrd2= $.Deferred();

    setTimeout(function(){
        // doing async stuff
        console.log('task 1 in function1 is done!');
        dfrd1.resolve();
    }, 1000);

    setTimeout(function(){
        // doing more async stuff
        console.log('task 2 in function1 is done!');
        dfrd2.resolve();
    }, 750);

    return $.when(dfrd1, dfrd2).done(function(){
        console.log('both tasks in function1 are done');
        // Both asyncs tasks are done
    }).promise();
}

function function2(){
    var dfrd1 = $.Deferred();
    setTimeout(function(){
        // doing async stuff
        console.log('task 1 in function2 is done!');
        dfrd1.resolve();
    }, 2000);
    return dfrd1.promise();
}

How to make sure that string is valid JSON using JSON.NET

Use JContainer.Parse(str) method to check if the str is a valid Json. If this throws exception then it is not a valid Json.

JObject.Parse - Can be used to check if the string is a valid Json object
JArray.Parse - Can be used to check if the string is a valid Json Array
JContainer.Parse - Can be used to check for both Json object & Array

isset() and empty() - what to use

Here are the outputs of isset() and empty() for the 4 possibilities: undeclared, null, false and true.

$a=null;
$b=false;
$c=true;

var_dump(array(isset($z1),isset($a),isset($b),isset($c)),true); //$z1 previously undeclared
var_dump(array(empty($z2),empty($a),empty($b),empty($c)),true); //$z2 previously undeclared

//array(4) { [0]=> bool(false) [1]=> bool(false) [2]=> bool(true) [3]=> bool(true) } 
//array(4) { [0]=> bool(true) [1]=> bool(true) [2]=> bool(true) [3]=> bool(false) } 

You'll notice that all the 'isset' results are opposite of the 'empty' results except for case $b=false. All the values (except null which isn't a value but a non-value) that evaluate to false will return true when tested for by isset and false when tested by 'empty'.

So use isset() when you're concerned about the existence of a variable. And use empty when you're testing for true or false. If the actual type of emptiness matters, use is_null and ===0, ===false, ===''.

CSS full screen div with text in the middle

There is no pure CSS solution to this classical problem.

If you want to achieve this, you have two solutions:

  • Using a table (ugly, non semantic, but the only way to vertically align things that are not a single line of text)
  • Listening to window.resize and absolute positionning

EDIT: when I say that there is no solution, I take as an hypothesis that you don't know in advance the size of the block to center. If you know it, paislee's solution is very good

How to make a <div> appear in front of regular text/tables

You may add a div with position:absolute within a table/div with position:relative. For example, if you want your overlay div to be shown at the bottom right of the main text div (width and height can be removed):

<div style="position:relative;width:300px;height:300px;background-color:#eef">
    <div style="position:absolute;bottom:0;right:0;width:100px;height:100px;background-color:#fee">
        I'm over you!
    </div>
    Your main text
</div>

See it here: http://jsfiddle.net/bptvt5kb/

Error: Module not specified (IntelliJ IDEA)

Faced the same issue. To solve it,

iOS 8 removed "minimal-ui" viewport property, are there other "soft fullscreen" solutions?

The root problem here seems that iOS8 safari won't hide the address bar when scrolling down if the content is equal or less than the viewport.

As you found out already, adding some padding at the bottom gets around this issue:

html {
    /* enough space to scroll up to get fullscreen on iOS8 */
    padding-bottom: 80px;
}
// sort of emulate safari's "bounce back to top" scroll
window.addEventListener('scroll', function(ev) {
    // avoids scrolling when the focused element is e.g. an input
    if (
        !document.activeElement
        || document.activeElement === document.body
    ) {
        document.body.scrollIntoViewIfNeeded(true);
    }
});

The above css should be conditionally applied, for example with UA sniffing adding a gt-ios8 class to <html>.

How do I concatenate two text files in PowerShell?

Simply use the Get-Content and Set-Content cmdlets:

Get-Content inputFile1.txt, inputFile2.txt | Set-Content joinedFile.txt

You can concatenate more than two files with this style, too.

If the source files are named similarly, you can use wildcards:

Get-Content inputFile*.txt | Set-Content joinedFile.txt

Note 1: PowerShell 5 and older versions allowed this to be done more concisely using the aliases cat and sc for Get-Content and Set-Content respectively. However, these aliases are problematic because cat is a system command in *nix systems, and sc is a system command in Windows systems - therefore using them is not recommended, and in fact sc is no longer even defined as of PowerShell Core (v7). The PowerShell team recommends against using aliases in general.

Note 2: Be careful with wildcards - if you try to output to examples.txt (or similar that matches the pattern), PowerShell will get into an infinite loop! (I just tested this.)

Note 3: Outputting to a file with > does not preserve character encoding! This is why using Set-Content is recommended.

Difference between "module.exports" and "exports" in the CommonJs Module System

Renee's answer is well explained. Addition to the answer with an example:

Node does a lot of things to your file and one of the important is WRAPPING your file. Inside nodejs source code "module.exports" is returned. Lets take a step back and understand the wrapper. Suppose you have

greet.js

var greet = function () {
   console.log('Hello World');
};

module.exports = greet;

the above code is wrapped as IIFE(Immediately Invoked Function Expression) inside nodejs source code as follows:

(function (exports, require, module, __filename, __dirname) { //add by node

      var greet = function () {
         console.log('Hello World');
      };

      module.exports = greet;

}).apply();                                                  //add by node

return module.exports;                                      //add by node

and the above function is invoked (.apply()) and returned module.exports. At this time module.exports and exports pointing to the same reference.

Now, imagine you re-write greet.js as

exports = function () {
   console.log('Hello World');
};
console.log(exports);
console.log(module.exports);

the output will be

[Function]
{}

the reason is : module.exports is an empty object. We did not set anything to module.exports rather we set exports = function()..... in new greet.js. So, module.exports is empty.

Technically exports and module.exports should point to same reference(thats correct!!). But we use "=" when assigning function().... to exports, which creates another object in the memory. So, module.exports and exports produce different results. When it comes to exports we can't override it.

Now, imagine you re-write (this is called Mutation) greet.js (referring to Renee answer) as

exports.a = function() {
    console.log("Hello");
}

console.log(exports);
console.log(module.exports);

the output will be

{ a: [Function] }
{ a: [Function] }

As you can see module.exports and exports are pointing to same reference which is a function. If you set a property on exports then it will be set on module.exports because in JS, objects are pass by reference.

Conclusion is always use module.exports to avoid confusion. Hope this helps. Happy coding :)

How do I find which transaction is causing a "Waiting for table metadata lock" state?

mysql 5.7 exposes metadata lock information through the performance_schema.metadata_locks table.

Documentation here

Gnuplot line types

Until version 4.6

The dash type of a linestyle is given by the linetype, which does also select the line color unless you explicitely set an other one with linecolor.

However, the support for dashed lines depends on the selected terminal:

  1. Some terminals don't support dashed lines, like png (uses libgd)
  2. Other terminals, like pngcairo, support dashed lines, but it is disables by default. To enable it, use set termoption dashed, or set terminal pngcairo dashed ....
  3. The exact dash patterns differ between terminals. To see the defined linetype, use the test command:

Running

set terminal pngcairo dashed
set output 'test.png'
test
set output

gives:

enter image description here

whereas, the postscript terminal shows different dash patterns:

set terminal postscript eps color colortext
set output 'test.eps'
test
set output

enter image description here

Version 5.0

Starting with version 5.0 the following changes related to linetypes, dash patterns and line colors are introduced:

  • A new dashtype parameter was introduced:

    To get the predefined dash patterns, use e.g.

    plot x dashtype 2
    

    You can also specify custom dash patterns like

    plot x dashtype (3,5,10,5),\
         2*x dashtype '.-_'
    
  • The terminal options dashed and solid are ignored. By default all lines are solid. To change them to dashed, use e.g.

    set for [i=1:8] linetype i dashtype i
    
  • The default set of line colors was changed. You can select between three different color sets with set colorsequence default|podo|classic:

enter image description here

Passing arguments to JavaScript function from code-behind

Look at the ScriptManager.RegisterStartupScript method if you're using a ScriptManager or any Ajax controls/asynchronous postbacks.

Edit:

Actually, the function you want is probably ScriptManager.RegisterClientScriptBlock

How can I style an Android Switch?

It's an awesome detailed reply by Janusz. But just for the sake of people who are coming to this page for answers, the easier way is at http://android-holo-colors.com/ (dead link) linked from Android Asset Studio

A good description of all the tools are at AndroidOnRocks.com (site offline now)

However, I highly recommend everybody to read the reply from Janusz as it will make understanding clearer. Use the tool to do stuffs real quick

Windows ignores JAVA_HOME: how to set JDK as default?

There's an additional factor here; in addition to the java executables that the java installation puts wherever you ask it to put them, on windows, the java installer also puts copies of some of those executables in your windows system32 directory, so you will likely be using which every java executable was installed most recently.

How to check edittext's text is email address or not?

for email validation try this.

public boolean checkemail(String email)
{

    Pattern pattern = Pattern.compile(".+@.+\\.[a-z]+");
    Matcher matcher = pattern.matcher(email);
    return matcher.matches();

}

if (select count(column) from table) > 0 then

Edit:

The oracle tag was not on the question when this answer was offered, and apparently it doesn't work with oracle, but it does work with at least postgres and mysql

No, just use the value directly:

begin
  if (select count(*) from table) > 0 then
     update table
  end if;
end;

Note there is no need for an "else".

Edited

You can simply do it all within the update statement (ie no if construct):

update table
set ...
where ...
and exists (select 'x' from table where ...)

Get string between two strings in a string

or, with a regex.

using System.Text.RegularExpressions;

...

var value =
    Regex.Match(
        "super exemple of string key : text I want to keep - end of my string",
        "key : (.*) - ")
    .Groups[1].Value;

with a running example.

You can decide if its overkill.

or

as an under validated extension method

using System.Text.RegularExpressions;

public class Test
{
    public static void Main()
    {
        var value =
                "super exemple of string key : text I want to keep - end of my string"
                    .Between(
                        "key : ",
                        " - ");

        Console.WriteLine(value);
    }
}

public static class Ext
{
    static string Between(this string source, string left, string right)
    {
        return Regex.Match(
                source,
                string.Format("{0}(.*){1}", left, right))
            .Groups[1].Value;
    }
}

java.net.SocketException: Connection reset by peer: socket write error When serving a file

It is possible for the TCP socket to be "closing" and your code to not have yet been notified.

Here is a animation for the life cycle. http://tcp.cs.st-andrews.ac.uk/index.shtml?page=connection_lifecycle

Basically, the connection was closed by the client. You already have throws IOException and SocketException extends IOException. This is working just fine. You just need to properly handle IOException because it is a normal part of the api.

EDIT: The RST packet occurs when a packet is received on a socket which does not exist or was closed. There is no difference to your application. Depending on the implementation the reset state may stick and closed will never officially occur.

How to properly upgrade node using nvm

This may work:

nvm install NEW_VERSION --reinstall-packages-from=OLD_VERSION

For example:

nvm install 6.7 --reinstall-packages-from=6.4

then, if you want, you can delete your previous version with:

nvm uninstall OLD_VERSION

Where, in your case, NEW_VERSION = 5.4 OLD_VERSION = 5.0

Alternatively, try:

nvm install stable --reinstall-packages-from=current

Determine if a String is an Integer in Java

public boolean isInt(String str){
    return (str.lastIndexOf("-") == 0 && !str.equals("-0")) ? str.substring(1).matches(
            "\\d+") : str.matches("\\d+");
}

Bootstrap 4: responsive sidebar menu to top navbar

It could be done in Bootstrap 4 using the responsive grid columns. One column for the sidebar and one for the main content.

Bootstrap 4 Sidebar switch to Top Navbar on mobile

<div class="container-fluid h-100">
    <div class="row h-100">
        <aside class="col-12 col-md-2 p-0 bg-dark">
            <nav class="navbar navbar-expand navbar-dark bg-dark flex-md-column flex-row align-items-start">
                <div class="collapse navbar-collapse">
                    <ul class="flex-md-column flex-row navbar-nav w-100 justify-content-between">
                        <li class="nav-item">
                            <a class="nav-link pl-0" href="#">Link</a>
                        </li>
                        ..
                    </ul>
                </div>
            </nav>
        </aside>
        <main class="col">
            ..
        </main>
    </div>
</div>

Alternate sidebar to top
Fixed sidebar to top

For the reverse (Top Navbar that becomes a Sidebar), can be done like this example

Using Node.js require vs. ES6 import/export

Are there any performance benefits to using one over the other?

Keep in mind that there is no JavaScript engine yet that natively supports ES6 modules. You said yourself that you are using Babel. Babel converts import and export declaration to CommonJS (require/module.exports) by default anyway. So even if you use ES6 module syntax, you will be using CommonJS under the hood if you run the code in Node.

There are technical differences between CommonJS and ES6 modules, e.g. CommonJS allows you to load modules dynamically. ES6 doesn't allow this, but there is an API in development for that.

Since ES6 modules are part of the standard, I would use them.


Update 2020

Since Node v12, support for ES modules is enabled by default, but it's still experimental at the time of writing this. Files including node modules must either end in .mjs or the nearest package.json file must contain "type": "module". The Node documentation has a ton more information, also about interop between CommonJS and ES modules.

Performance-wise there is always the chance that newer features are not as well optimized as existing features. However, since module files are only evaluated once, the performance aspect can probably be ignored. In the end you have to run benchmarks to get a definite answer anyway.

ES modules can be loaded dynamically via the import() function. Unlike require, this returns a promise.

Android: alternate layout xml for landscape mode

I will try to explain it shortly.

First, you may notice that now you should use ConstraintLayout as requested by google (see androix library).

In your android studio projet, you can provide screen-specific layouts by creating additional res/layout/ directories. One for each screen configuration that requires a different layout.

This means you have to use the directory qualifier in both cases :

  • Android device support
  • Android landscape or portrait mode

As a result, here is an exemple :

res/layout/main_activity.xml                # For handsets
res/layout-land/main_activity.xml           # For handsets in landscape
res/layout-sw600dp/main_activity.xml        # For 7” tablets
res/layout-sw600dp-land/main_activity.xml   # For 7” tablets in landscape

You can also use qualifier with res ressources files using dimens.xml.

res/values/dimens.xml                # For handsets
res/values-land/dimens.xml           # For handsets in landscape
res/values-sw600dp/dimens.xml        # For 7” tablets

res/values/dimens.xml

<resources>
    <dimen name="grid_view_item_height">70dp</dimen>
</resources>

res/values-land/dimens.xml

<resources>
    <dimen name="grid_view_item_height">150dp</dimen>
</resources>

your_item_grid_or_list_layout.xml

<androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/constraintlayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content

    <ImageView
            android:id="@+id/image"
            android:layout_width="0dp"
            android:layout_height="@dimen/grid_view_item_height"
            android:layout_marginEnd="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:background="@drawable/border"
            android:src="@drawable/ic_menu_slideshow">

</androidx.constraintlayout.widget.ConstraintLayout>

Source : https://developer.android.com/training/multiscreen/screensizes

Is it possible to set ENV variables for rails development environment in my code?

The way I am trying to do this in my question actually works!

# environment/development.rb

ENV['admin_password'] = "secret" 

I just had to restart the server. I thought running reload! in rails console would be enough but I also had to restart the web server.

I am picking my own answer because I feel this is a better place to put and set the ENV variables

Code formatting shortcuts in Android Studio for Operation Systems

Really, I went to this thread because of my Ubuntu locks screen after this shortcut Ctrl + Alt + L. So if you are have the same problem just go to the Settings - Keyboard - Shortcuts - System and change the default shortcut for the "Lock screen".

How to fix Cannot find module 'typescript' in Angular 4?

Run 'npm install' it will install all necessary pkg .

How to set OnClickListener on a RadioButton in Android?

Just in case someone else was struggeling with the accepted answer:

There are different OnCheckedChangeListener-Interfaces. I added to first one to see if a CheckBox was changed.

import android.widget.CompoundButton.OnCheckedChangeListener;

vs

import android.widget.RadioGroup.OnCheckedChangeListener;

When adding the snippet from Ricky I had errors:

The method setOnCheckedChangeListener(RadioGroup.OnCheckedChangeListener) in the type RadioGroup is not applicable for the arguments (new CompoundButton.OnCheckedChangeListener(){})

Can be fixed with answer from Ali :

new RadioGroup.OnCheckedChangeListener()

Edit In Place Content Editing

I was looking for a inline editing solution and I found a plunker that seemed promising, but it didn't work for me out of the box. After some tinkering with the code I got it working. Kudos to the person who made the initial effort to code this piece.

The example is available here http://plnkr.co/edit/EsW7mV?p=preview

Here goes the code:

app.controller('MainCtrl', function($scope) {

  $scope.updateTodo = function(indx) {
    console.log(indx);
  };

  $scope.cancelEdit = function(value) {
    console.log('Canceled editing', value);
  };

  $scope.todos = [
    {id:123, title: 'Lord of the things'},
    {id:321, title: 'Hoovering heights'},
    {id:231, title: 'Watership brown'}
  ];
});

// On esc event
app.directive('onEsc', function() {
  return function(scope, elm, attr) {
    elm.bind('keydown', function(e) {
      if (e.keyCode === 27) {
        scope.$apply(attr.onEsc);
      }
    });
  };
});

// On enter event
app.directive('onEnter', function() {
  return function(scope, elm, attr) {
    elm.bind('keypress', function(e) {
      if (e.keyCode === 13) {
        scope.$apply(attr.onEnter);
      }
    });
  };
});

// Inline edit directive
app.directive('inlineEdit', function($timeout) {
  return {
    scope: {
      model: '=inlineEdit',
      handleSave: '&onSave',
      handleCancel: '&onCancel'
    },
    link: function(scope, elm, attr) {
      var previousValue;

      scope.edit = function() {
        scope.editMode = true;
        previousValue = scope.model;

        $timeout(function() {
          elm.find('input')[0].focus();
        }, 0, false);
      };
      scope.save = function() {
        scope.editMode = false;
        scope.handleSave({value: scope.model});
      };
      scope.cancel = function() {
        scope.editMode = false;
        scope.model = previousValue;
        scope.handleCancel({value: scope.model});
      };
    },
    templateUrl: 'inline-edit.html'
  };
});

Directive template:

<div>
  <input type="text" on-enter="save()" on-esc="cancel()" ng-model="model" ng-show="editMode">
  <button ng-click="cancel()" ng-show="editMode">cancel</button>
  <button ng-click="save()" ng-show="editMode">save</button>
  <span ng-mouseenter="showEdit = true" ng-mouseleave="showEdit = false">
    <span ng-hide="editMode" ng-click="edit()">{{model}}</span>
    <a ng-show="showEdit" ng-click="edit()">edit</a>
  </span>
</div>

To use it just add water:

<div ng-repeat="todo in todos" 
     inline-edit="todo.title" 
     on-save="updateTodo($index)" 
     on-cancel="cancelEdit(todo.title)"></div>

UPDATE:

Another option is to use the readymade Xeditable for AngularJS:

http://vitalets.github.io/angular-xeditable/

How to merge remote changes at GitHub?

This problem can also occur when you have conflicting tags. If your local version and remote version use same tag name for different commits, you can end up here.

You can solve it my deleting the local tag:

$ git tag --delete foo_tag

Disabling browser caching for all browsers from ASP.NET

This is what we use in ASP.NET:

// Stop Caching in IE
Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);

// Stop Caching in Firefox
Response.Cache.SetNoStore();

It stops caching in Firefox and IE, but we haven't tried other browsers. The following response headers are added by these statements:

Cache-Control: no-cache, no-store
Pragma: no-cache

In OS X Lion, LANG is not set to UTF-8, how to fix it?

I recently had the same issue on OS X Sierra with bash shell, and thanks to answers above I only had to edit the file

~/.bash_profile 

and append those lines

export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8

Submit form using AJAX and jQuery

There is a nice form plugin that allows you to send an HTML form asynchroniously.

$(document).ready(function() { 
    $('#myForm1').ajaxForm(); 
});

or

$("select").change(function(){
    $('#myForm1').ajaxSubmit();
});

to submit the form immediately

Read SQL Table into C# DataTable

Here, give this a shot (this is just a pseudocode)

using System;
using System.Data;
using System.Data.SqlClient;


public class PullDataTest
{
    // your data table
    private DataTable dataTable = new DataTable();

    public PullDataTest()
    {
    }

    // your method to pull data from database to datatable   
    public void PullData()
    {
        string connString = @"your connection string here";
        string query = "select * from table";

        SqlConnection conn = new SqlConnection(connString);        
        SqlCommand cmd = new SqlCommand(query, conn);
        conn.Open();

        // create data adapter
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        // this will query your database and return the result to your datatable
        da.Fill(dataTable);
        conn.Close();
        da.Dispose();
    }
}

Eclipse does not highlight matching variables

I had this issue with Eclipse Mars for PHP developers, 64 bit edition for Windows. I now discovered that highlighting works out-of-the-box with the 32 bit version. Even with a fresh download of the equivalent 64 bit build, highlighting does not work. So I will switch back to 32 bit (this is actually not the first problem I observe with Eclipse 64 bit).

Edit:

I thought this was the solution, so I installed the 32 bit version in C:\Program Files (x86) and set a shortcut in the "Start" menu. When I started Eclipse from there, highlighting again ceased to work. I now got it working again by deleting the .metadata directory in the workspace (i.e. resetting the workspace settings) and re-importing the projects.

Free FTP Library

I've just posted an article that presents both an FTP client class and an FTP user control.

They are simple and aren't very fast, but are very easy to use and all source code is included. Just drop the user control onto a form to allow users to navigate FTP directories from your application.

How to show progress bar while loading, using ajax

try this it may help you

 $.ajax({
  type:"post",
            url:"clientnetworkpricelist/yourfile.php",
        data:"title="+clientid,
  beforeSend: function(  ) {
    // load your loading fiel here
  }
})
  .done(function( data ) {
    //hide your loading file here
  });

How to ping multiple servers and return IP address and Hostnames using batch script?

Parsing pingtest.txt for each HOST name and result with batch is difficult because the name and result are on different lines.

It is much easier to test the result (the returned error code) of each PING command directly instead of redirecting to a file. It is also more efficient to enclose the entire construct in parens and redirect the final output just once.

>result.txt (
  for /f %%i in (testservers.txt) do ping -n 1 %%i >nul && echo %%i UP||echo %%i DOWN
)

Executing "SELECT ... WHERE ... IN ..." using MySQLdb

Have been trying every variation on João's solution to get an IN List query to work with Tornado's mysql wrapper, and was still getting the accursed "TypeError: not enough arguments for format string" error. Turns out adding "*" to the list var "*args" did the trick.

args=['A', 'C']
sql='SELECT fooid FROM foo WHERE bar IN (%s)'
in_p=', '.join(list(map(lambda x: '%s', args)))
sql = sql % in_p
db.query(sql, *args)

How to download Xcode DMG or XIP file?

You can find the DMGs or XIPs for Xcode and other development tools on https://developer.apple.com/download/more/ (requires Apple ID to login).

You must login to have a valid session before downloading anything below.

*(Newest on top. For each minor version (6.3, 5.1, etc.) only the latest revision is kept in the list.)

*With Xcode 12.2, Apple introduces the term “Release Candidate” (RC) which replaces “GM seed” and indicates this version is near final.

Xcode 12

  • 12.4 (requires a Mac with Apple silicon running macOS Big Sur 11 or later, or an Intel-based Mac running macOS Catalina 10.15.4 or later) (Latest as of 27-Jan-2021)

  • 12.3 (requires a Mac with Apple silicon running macOS Big Sur 11 or later, or an Intel-based Mac running macOS Catalina 10.15.4 or later)

  • 12.2

  • 12.1

  • 12.0.1 (Requires macOS 10.15.4 or later) (Latest as of 24-Sept-2020)

Xcode 11

Xcode 10 (unsupported for iTunes Connect)

  • 10.3 (Requires macOS 10.14.3 or later)
  • 10.2.1 (Requires macOS 10.14.3 or later)
  • 10.1 (Last version supporting macOS 10.13.6 High Sierra)
  • 10 (Subsequent versions were unsupported for iTunes Connect from March 2019)

Xcode 9

Xcode 8

Xcode 7

Xcode 6

Even Older Versions (unsupported for iTunes Connect)

How to prevent rm from reporting that a file was not found?

-f is the correct flag, but for the test operator, not rm

[ -f "$THEFILE" ] && rm "$THEFILE"

this ensures that the file exists and is a regular file (not a directory, device node etc...)

Setting environment variables via launchd.conf no longer works in OS X Yosemite/El Capitan/macOS Sierra/Mojave?

You can give https://github.com/ersiner/osx-env-sync a try. It handles both command line and GUI apps from a single source and works withe the latest version of OS X (Yosemite).

You can use path substitutions and other shell tricks since what you write is regular bash script to be sourced by bash in the first place. No restrictions.. (Check osx-env-sync documentation and you'll understand how it achieves this.)

I answered a similar question here where you'll find more.

how to do bitwise exclusive or of two strings in python?

def strxor (s0, s1):
  l = [ chr ( ord (a) ^ ord (b) ) for a,b in zip (s0, s1) ]
  return ''.join (l)

(Based on Mark Byers answer.)

Grant all on a specific schema in the db to a group role in PostgreSQL

My answer is similar to this one on ServerFault.com.

To Be Conservative

If you want to be more conservative than granting "all privileges", you might want to try something more like these.

GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA public TO some_user_;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA public TO some_user_;

The use of public there refers to the name of the default schema created for every new database/catalog. Replace with your own name if you created a schema.

Access to the Schema

To access a schema at all, for any action, the user must be granted "usage" rights. Before a user can select, insert, update, or delete, a user must first be granted "usage" to a schema.

You will not notice this requirement when first using Postgres. By default every database has a first schema named public. And every user by default has been automatically been granted "usage" rights to that particular schema. When adding additional schema, then you must explicitly grant usage rights.

GRANT USAGE ON SCHEMA some_schema_ TO some_user_ ;

Excerpt from the Postgres doc:

For schemas, allows access to objects contained in the specified schema (assuming that the objects' own privilege requirements are also met). Essentially this allows the grantee to "look up" objects within the schema. Without this permission, it is still possible to see the object names, e.g. by querying the system tables. Also, after revoking this permission, existing backends might have statements that have previously performed this lookup, so this is not a completely secure way to prevent object access.

For more discussion see the Question, What GRANT USAGE ON SCHEMA exactly do?. Pay special attention to the Answer by Postgres expert Craig Ringer.

Existing Objects Versus Future

These commands only affect existing objects. Tables and such you create in the future get default privileges until you re-execute those lines above. See the other answer by Erwin Brandstetter to change the defaults thereby affecting future objects.

jQuery textbox change event doesn't fire until textbox loses focus?

Reading your comments took me to a dirty fix. This is not a right way, I know, but can be a work around.

$(function() {
    $( "#inputFieldId" ).autocomplete({
        source: function( event, ui ) {
            alert("do your functions here");
            return false;
        }
    });
});

Error related to only_full_group_by when executing a query in MySql

If you have this error with Symfony using doctrine query builder, and if this error is caused by an orderBy :

Pay attention to select the column you want to groupBy, and use addGroupBy instead of groupBy :

$query = $this->createQueryBuilder('smth')->addGroupBy('smth.mycolumn');

Works on Symfony3 -

Javascript one line If...else...else if statement

Sure, you can do nested ternary operators but they are hard to read.

var variable = (condition) ? (true block) : ((condition2) ? (true block2) : (else block2))

Compare two different files line by line in python

If order is preserved between files you might also prefer difflib. Although Rob?'s result is the bona-fide standard for intersections you might actually be looking for a rough diff-like:

from difflib import Differ

with open('cfg1.txt') as f1, open('cfg2.txt') as f2:
    differ = Differ()

    for line in differ.compare(f1.readlines(), f2.readlines()):
        if line.startswith(" "):
            print(line[2:], end="")

That said, this has a different behaviour to what you asked for (order is important) even though in this instance the same output is produced.

Turn off display errors using file "php.ini"

I always use something like this in a configuration file:

// Toggle this to change the setting
define('DEBUG', true);

// You want all errors to be triggered
error_reporting(E_ALL);

if(DEBUG == true)
{
    // You're developing, so you want all errors to be shown
    display_errors(true);

    // Logging is usually overkill during development
    log_errors(false);
}
else
{
    // You don't want to display errors on a production environment
    display_errors(false);

    // You definitely want to log any occurring
    log_errors(true);
}

This allows easy toggling between debug settings. You can improve this further by checking on which server the code is running (development, test, acceptance, and production) and change your settings accordingly.

Note that no errors will be logged if error_reporting is set to 0, as cleverly remarked by Korri.

changing color of h2

Try CSS:

<h2 style="color:#069">Process Report</h2>

If you have more than one h2 tags which should have the same color add a style tag to the head tag like this:

<style type="text/css">
h2 {
    color:#069;
}
</style>

Bootstrap Align Image with text

You have two choices, either correct your markup so that it uses correct elements and utilizes the Bootstrap grid system:

_x000D_
_x000D_
@import url('http://getbootstrap.com/dist/css/bootstrap.css');
_x000D_
<div class="container">_x000D_
     <h1>About Me</h1>_x000D_
    <div class="row">_x000D_
        <div class="col-md-4">_x000D_
            <div class="imgAbt">_x000D_
                <img width="220" height="220" src="img/me.jpg" />_x000D_
            </div>_x000D_
        </div>_x000D_
        <div class="col-md-8">_x000D_
            <p>Lots of text here...With the four tiers of grids available you're bound to run into issues where, at certain breakpoints, your columns don't clear quite right as one is taller than the other. To fix that, use a combination of a .clearfix and o</p>_x000D_
        </div>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Or, if you wish the text to closely wrap the image, change your markup to:

_x000D_
_x000D_
@import url('http://getbootstrap.com/dist/css/bootstrap.css');
_x000D_
<div class="container">_x000D_
    <h1>About Me</h1>_x000D_
    <div class="row">_x000D_
        <div class="col-md-12">_x000D_
            <img style='float:left;width:200px;height:200px; margin-right:10px;' src="img/me.jpg" />_x000D_
            <p>Lots of text here...With the four tiers of grids available you're bound to run into issues where, at certain breakpoints, your columns don't clear quite right as one is taller than the other. To fix that, use a combination of a .clearfix and o</p>_x000D_
        </div>_x000D_
    </div>
_x000D_
_x000D_
_x000D_

TypeError: 'int' object is not subscriptable

Try this instead:

sumall = summ + sumd + sumy
print "The sum of your numbers is", sumall
sumall = str(sumall) # add this line
sumln = (int(sumall[0])+int(sumall[1]))
print "Your lucky number is", sumln

sumall is a number, and you can't access its digits using the subscript notation (sumall[0], sumall[1]). For that to work, you'll need to transform it back to a string.

Get the size of the screen, current web page and browser window

If you need a truly bulletproof solution for the document width and height (the pageWidth and pageHeight in the picture), you might want to consider using a plugin of mine, jQuery.documentSize.

It has just one purpose: to always return the correct document size, even in scenarios when jQuery and other methods fail. Despite its name, you don't necessarily have to use jQuery – it is written in vanilla Javascript and works without jQuery, too.

Usage:

var w = $.documentWidth(),
    h = $.documentHeight();

for the global document. For other documents, e.g. in an embedded iframe you have access to, pass the document as a parameter:

var w = $.documentWidth( myIframe.contentDocument ),
    h = $.documentHeight( myIframe.contentDocument );

Update: now for window dimensions, too

Ever since version 1.1.0, jQuery.documentSize also handles window dimensions.

That is necessary because

  • $( window ).height() is buggy in iOS, to the point of being useless
  • $( window ).width() and $( window ).height() are unreliable on mobile because they don't handle the effects of mobile zooming.

jQuery.documentSize provides $.windowWidth() and $.windowHeight(), which solve these issues. For more, please check out the documentation.

Can pandas automatically recognize dates?

Yes - according to the pandas.read_csv documentation:

Note: A fast-path exists for iso8601-formatted dates.

So if your csv has a column named datetime and the dates looks like 2013-01-01T01:01 for example, running this will make pandas (I'm on v0.19.2) pick up the date and time automatically:

df = pd.read_csv('test.csv', parse_dates=['datetime'])

Note that you need to explicitly pass parse_dates, it doesn't work without.

Verify with:

df.dtypes

You should see the datatype of the column is datetime64[ns]

Relative URLs in WordPress

<?php wp_make_link_relative( $link ) ?>

Convert full URL paths to relative paths.

Removes the http or https protocols and the domain. Keeps the path '/' at the beginning, so it isn't a true relative link, but from the web root base.

Reference: Wordpress Codex

IIS7 - The request filtering module is configured to deny a request that exceeds the request content length

The following example Web.config file will configure IIS to deny access for HTTP requests where the length of the "Content-type" header is greater than 100 bytes.

  <configuration>
   <system.webServer>
      <security>
         <requestFiltering>
            <requestLimits>
               <headerLimits>
                  <add header="Content-type" sizeLimit="100" />
               </headerLimits>
            </requestLimits>
         </requestFiltering>
      </security>
   </system.webServer>
</configuration>

Source: http://www.iis.net/configreference/system.webserver/security/requestfiltering/requestlimits

How to return a string value from a Bash function

To illustrate my comment on Andy's answer, with additional file descriptor manipulation to avoid use of /dev/tty:

#!/bin/bash

exec 3>&1

returnString() {
    exec 4>&1 >&3
    local s=$1
    s=${s:="some default string"}
    echo "writing to stdout"
    echo "writing to stderr" >&2
    exec >&4-
    echo "$s"
}

my_string=$(returnString "$*")
echo "my_string:  [$my_string]"

Still nasty, though.

How do I see active SQL Server connections?

Below is my script to find all the sessions connected to a database and you can check if those sessions are doing any I/O and there is an option to kill them.

The script shows also the status of each session.

Have a look below.

--==============================================================================
-- See who is connected to the database.
-- Analyse what each spid is doing, reads and writes.
-- If safe you can copy and paste the killcommand - last column.
-- Marcelo Miorelli
-- 18-july-2017 - London (UK)
-- Tested on SQL Server 2016.
--==============================================================================
USE master
go
SELECT
     sdes.session_id
    ,sdes.login_time
    ,sdes.last_request_start_time
    ,sdes.last_request_end_time
    ,sdes.is_user_process
    ,sdes.host_name
    ,sdes.program_name
    ,sdes.login_name
    ,sdes.status

    ,sdec.num_reads
    ,sdec.num_writes
    ,sdec.last_read
    ,sdec.last_write
    ,sdes.reads
    ,sdes.logical_reads
    ,sdes.writes

    ,sdest.DatabaseName
    ,sdest.ObjName
    ,sdes.client_interface_name
    ,sdes.nt_domain
    ,sdes.nt_user_name
    ,sdec.client_net_address
    ,sdec.local_net_address
    ,sdest.Query
    ,KillCommand  = 'Kill '+ CAST(sdes.session_id  AS VARCHAR)
FROM sys.dm_exec_sessions AS sdes

INNER JOIN sys.dm_exec_connections AS sdec
        ON sdec.session_id = sdes.session_id

CROSS APPLY (

    SELECT DB_NAME(dbid) AS DatabaseName
        ,OBJECT_NAME(objectid) AS ObjName
        ,COALESCE((
            SELECT TEXT AS [processing-instruction(definition)]
            FROM sys.dm_exec_sql_text(sdec.most_recent_sql_handle)
            FOR XML PATH('')
                ,TYPE
            ), '') AS Query

    FROM sys.dm_exec_sql_text(sdec.most_recent_sql_handle)

) sdest
WHERE sdes.session_id <> @@SPID
  AND sdest.DatabaseName ='yourdatabasename'
--ORDER BY sdes.last_request_start_time DESC

--==============================================================================

What are rvalues, lvalues, xvalues, glvalues, and prvalues?

I guess this document might serve as a not so short introduction : n3055

The whole massacre began with the move semantics. Once we have expressions that can be moved and not copied, suddenly easy to grasp rules demanded distinction between expressions that can be moved, and in which direction.

From what I guess based on the draft, the r/l value distinction stays the same, only in the context of moving things get messy.

Are they needed? Probably not if we wish to forfeit the new features. But to allow better optimization we should probably embrace them.

Quoting n3055:

  • An lvalue (so-called, historically, because lvalues could appear on the left-hand side of an assignment expression) designates a function or an object. [Example: If E is an expression of pointer type, then *E is an lvalue expression referring to the object or function to which E points. As another example, the result of calling a function whose return type is an lvalue reference is an lvalue.]
  • An xvalue (an “eXpiring” value) also refers to an object, usually near the end of its lifetime (so that its resources may be moved, for example). An xvalue is the result of certain kinds of expressions involving rvalue references. [Example: The result of calling a function whose return type is an rvalue reference is an xvalue.]
  • A glvalue (“generalized” lvalue) is an lvalue or an xvalue.
  • An rvalue (so-called, historically, because rvalues could appear on the right-hand side of an assignment expression) is an xvalue, a temporary object or subobject thereof, or a value that is not associated with an object.
  • A prvalue (“pure” rvalue) is an rvalue that is not an xvalue. [Example: The result of calling a function whose return type is not a reference is a prvalue]

The document in question is a great reference for this question, because it shows the exact changes in the standard that have happened as a result of the introduction of the new nomenclature.

Android Activity without ActionBar

Default style you getting in res/value/style.xml like

  <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
  </style>

And just the below like in your activity tag,

android:theme="@style/AppTheme.NoActionBar"

Angular2 handling http response

in angular2 2.1.1 I was not able to catch the exception using the (data),(error) pattern, so I implemented it using .catch(...).

It's nice because it can be used with all other Observable chained methods like .retry .map etc.

import {Observable} from 'rxjs/Rx';


  Http
  .put(...)
  .catch(err =>  { 
     notify('UI error handling');
     return Observable.throw(err); // observable needs to be returned or exception raised
  })
  .subscribe(data => ...) // handle success

from documentation:

Returns

(Observable): An observable sequence containing elements from consecutive source sequences until a source sequence terminates successfully.

JOptionPane - input dialog box program

import java.util.SortedSet;
import java.util.TreeSet;

import javax.swing.JOptionPane;
import javax.swing.JFrame;

public class Average {

    public static void main(String [] args) {

        String test1= JOptionPane.showInputDialog("Please input mark for test 1: ");

        String test2= JOptionPane.showInputDialog("Please input mark for test 2: ");

        String test3= JOptionPane.showInputDialog("Please input mark for test 3: ");

        int int1 = Integer.parseInt(test1);
        int int2 = Integer.parseInt(test2);
        int int3 = Integer.parseInt(test3);

        SortedSet<Integer> set = new TreeSet<>();
        set.add(int1);
        set.add(int2);
        set.add(int3);

        Integer [] intArray = set.toArray(new Integer[3]);
        JFrame frame = new JFrame();
        JOptionPane.showInternalMessageDialog(frame.getContentPane(), String.format("Result %f", (intArray[1] + intArray[2]) / 2.0));

    }

}

How to replace an entire line in a text file by line number

in bash, replace N,M by the line numbers and xxx yyy by what you want

i=1
while read line;do
  if((i==N));then
    echo 'xxx'
  elif((i==M));then
    echo 'yyy'
  else
    echo "$line"
  fi
  ((i++))
done  < orig-file > new-file

EDIT

In fact in this solution there are some problems, with characters "\0" "\t" and "\"

"\t", can be solve by putting IFS= before read: "\", at end of line with -r

IFS= read -r line

but for "\0", the variable is truncated, there is no a solution in pure bash : Assign string containing null-character (\0) to a variable in Bash But in normal text file there is no nul character \0

perl would be a better choice

perl -ne 'if($.==N){print"xxx\n"}elsif($.==M){print"yyy\n"}else{print}' < orig-file > new-file

MVC Razor view nested foreach's model

When you are using foreach loop within view for binded model ... Your model is supposed to be in listed format.

i.e

@model IEnumerable<ViewModels.MyViewModels>


        @{
            if (Model.Count() > 0)
            {            

                @Html.DisplayFor(modelItem => Model.Theme.FirstOrDefault().name)
                @foreach (var theme in Model.Theme)
                {
                   @Html.DisplayFor(modelItem => theme.name)
                   @foreach(var product in theme.Products)
                   {
                      @Html.DisplayFor(modelItem => product.name)
                      @foreach(var order in product.Orders)
                      {
                          @Html.TextBoxFor(modelItem => order.Quantity)
                         @Html.TextAreaFor(modelItem => order.Note)
                          @Html.EditorFor(modelItem => order.DateRequestedDeliveryFor)
                      }
                  }
                }
            }else{
                   <span>No Theam avaiable</span>
            }
        }

How to View Oracle Stored Procedure using SQLPlus?

check your casing, the name is typically stored in upper case

SELECT * FROM all_source WHERE name = 'DAILY_UPDATE' ORDER BY TYPE, LINE;

Whether a variable is undefined

function my_url (base, opt)
{
    var retval = ["" + base];
    retval.push( opt.page_name ? "&page_name=" + opt.page_name : "");
    retval.push( opt.table_name ? "&table_name=" + opt.table_name : "");
    retval.push( opt.optionResult ? "&optionResult=" + opt.optionResult : "");
    return retval.join("");
}

my_url("?z=z",  { page_name : "pageX" /* no table_name and optionResult */ } );

/* Returns:
     ?z=z&page_name=pageX
*/

This avoids using typeof whatever === "undefined". (Also, there isn't any string concatenation.)

Using setTimeout to delay timing of jQuery actions

This is how I solved the problem The menu closes a few seconds after mouse out (that if hover didn't fire),

//Set timer switch
$setM_swith=0;

$(function(){
    $(".navbar-nav li a").click(function(event) {
        if (!$(this).parent().hasClass('dropdown'))
            $(".navbar-collapse").collapse('hide');
    });
    $(".navbar-collapse").mouseleave(function(){
        $setM_swith=1;
        setTimeout(function(){ 
           if($setM_swith==1) {
             $(".navbar-collapse").collapse('hide');
             $setM_swith=0;} 
        }, 3000);
    });
    $(".navbar-collapse").mouseover(function() {
        $setM_swith=0;
    });
 });

How do I convert a String to an int in Java?

It can be done in seven ways:

import com.google.common.primitives.Ints;
import org.apache.commons.lang.math.NumberUtils;

String number = "999";
  1. Ints.tryParse:

    int result = Ints.tryParse(number);

  2. NumberUtils.createInteger:

    Integer result = NumberUtils.createInteger(number);

  3. NumberUtils.toInt:

    int result = NumberUtils.toInt(number);

  4. Integer.valueOf:

    Integer result = Integer.valueOf(number);

  5. Integer.parseInt:

    int result = Integer.parseInt(number);

  6. Integer.decode:

    int result = Integer.decode(number);

  7. Integer.parseUnsignedInt:

    int result = Integer.parseUnsignedInt(number);

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

If you would like to open a servlet with javascript without using 'form' and 'submit' button, here is the following code:

var button = document.getElementById("<<button-id>>");
button.addEventListener("click", function() {
  window.location.href= "<<full-servlet-path>>" (eg. http://localhost:8086/xyz/servlet)
});

Key:

1) button-id : The 'id' tag you give to your button in your html/jsp file.

2) full-servlet-path: The path that shows in the browser when you run the servlet alone

Extracting numbers from vectors of strings

We can also use str_extract from stringr

years<-c("20 years old", "1 years old")
as.integer(stringr::str_extract(years, "\\d+"))
#[1] 20  1

If there are multiple numbers in the string and we want to extract all of them, we may use str_extract_all which unlike str_extract returns all the macthes.

years<-c("20 years old and 21", "1 years old")
stringr::str_extract(years, "\\d+")
#[1] "20"  "1"

stringr::str_extract_all(years, "\\d+")

#[[1]]
#[1] "20" "21"

#[[2]]
#[1] "1"

notifyDataSetChange not working from custom adapter

I have the same problem, and i realize that. When we create adapter and set it to listview, listview will point to object somewhere in memory which adapter hold, data in this object will show in listview.

adapter = new CustomAdapter(data);
listview.setadapter(adapter);

if we create an object for adapter with another data again and notifydatasetchanged():

adapter = new CustomAdapter(anotherdata);
adapter.notifyDataSetChanged();

this will do not affect to data in listview because the list is pointing to different object, this object does not know anything about new object in adapter, and notifyDataSetChanged() affect nothing. So we should change data in object and avoid to create a new object again for adapter

How do you send an HTTP Get Web Request in Python?

In Python, you can use urllib2 (http://docs.python.org/2/library/urllib2.html) to do all of that work for you.

Simply enough:

import urllib2
f =  urllib2.urlopen(url)
print f.read() 

Will print the received HTTP response.

To pass GET/POST parameters the urllib.urlencode() function can be used. For more information, you can refer to the Official Urllib2 Tutorial

how to get the last part of a string before a certain character?

You are looking for str.rsplit(), with a limit:

print x.rsplit('-', 1)[0]

.rsplit() searches for the splitting string from the end of input string, and the second argument limits how many times it'll split to just once.

Another option is to use str.rpartition(), which will only ever split just once:

print x.rpartition('-')[0]

For splitting just once, str.rpartition() is the faster method as well; if you need to split more than once you can only use str.rsplit().

Demo:

>>> x = 'http://test.com/lalala-134'
>>> print x.rsplit('-', 1)[0]
http://test.com/lalala
>>> 'something-with-a-lot-of-dashes'.rsplit('-', 1)[0]
'something-with-a-lot-of'

and the same with str.rpartition()

>>> print x.rpartition('-')[0]
http://test.com/lalala
>>> 'something-with-a-lot-of-dashes'.rpartition('-')[0]
'something-with-a-lot-of'

How to make Java Set?

Like this:

import java.util.*;
Set<Integer> a = new HashSet<Integer>();
a.add( 1);
a.add( 2);
a.add( 3);

Or adding from an Array/ or multiple literals; wrap to a list, first.

Integer[] array = new Integer[]{ 1, 4, 5};
Set<Integer> b = new HashSet<Integer>();
b.addAll( Arrays.asList( b));         // from an array variable
b.addAll( Arrays.asList( 8, 9, 10));  // from literals

To get the intersection:

// copies all from A;  then removes those not in B.
Set<Integer> r = new HashSet( a);
r.retainAll( b);
// and print;   r.toString() implied.
System.out.println("A intersect B="+r);

Hope this answer helps. Vote for it!

How can I format a nullable DateTime with ToString()?

Even a better solution in C# 6.0:

DateTime? birthdate;

birthdate?.ToString("dd/MM/yyyy");

Python 3 print without parenthesis

No. That will always be a syntax error in Python 3. Consider using 2to3 to translate your code to Python 3

How to concat string + i?

Using sprintf was already proposed by ldueck in a comment, but I think this is worth being an answer:

f(i) = sprintf('f%d', i);

This is in my opinion the most readable solution and also gives some nice flexibility (i.e. when you want to round a float value, use something like %.2f).

Get all files and directories in specific path fast

There is a long history of the .NET file enumeration methods being slow. The issue is there is not an instantaneous way of enumerating large directory structures. Even the accepted answer here has its issues with GC allocations.

The best I've been able to do is wrapped up in my library and exposed as the FindFile (source) class in the CSharpTest.Net.IO namespace. This class can enumerate files and folders without unneeded GC allocations and string marshalling.

The usage is simple enough, and the RaiseOnAccessDenied property will skip the directories and files the user does not have access to:

    private static long SizeOf(string directory)
    {
        var fcounter = new CSharpTest.Net.IO.FindFile(directory, "*", true, true, true);
        fcounter.RaiseOnAccessDenied = false;

        long size = 0, total = 0;
        fcounter.FileFound +=
            (o, e) =>
            {
                if (!e.IsDirectory)
                {
                    Interlocked.Increment(ref total);
                    size += e.Length;
                }
            };

        Stopwatch sw = Stopwatch.StartNew();
        fcounter.Find();
        Console.WriteLine("Enumerated {0:n0} files totaling {1:n0} bytes in {2:n3} seconds.",
                          total, size, sw.Elapsed.TotalSeconds);
        return size;
    }

For my local C:\ drive this outputs the following:

Enumerated 810,046 files totaling 307,707,792,662 bytes in 232.876 seconds.

Your mileage may vary by drive speed, but this is the fastest method I've found of enumerating files in managed code. The event parameter is a mutating class of type FindFile.FileFoundEventArgs so be sure you do not keep a reference to it as it's values will change for each event raised.

How to catch exception output from Python subprocess.check_output()?

This did the trick for me. It captures all the stdout output from the subprocess(For python 3.8):

from subprocess import check_output, STDOUT
cmd = "Your Command goes here"
try:
    cmd_stdout = check_output(cmd, stderr=STDOUT, shell=True).decode()
except Exception as e:
    print(e.output.decode()) # print out the stdout messages up to the exception
    print(e) # To print out the exception message

Jquery how to find an Object by attribute in an Array

Use the Underscore.js findWhere function (http://underscorejs.org/#findWhere):

var purposeObjects = [
    {purpose: "daily"},
    {purpose: "weekly"},
    {purpose: "monthly"}
];

var daily = _.findWhere(purposeObjects, {purpose: 'daily'});

daily would equal:

{"purpose":"daily"}

Here's a fiddle: http://jsfiddle.net/spencerw/oqbgc21x/

To return more than one (if you had more in your array) you could use _.where(...)

How do I find the last column with data?

Lots of ways to do this. The most reliable is find.

Dim rLastCell As Range

Set rLastCell = ws.Cells.Find(What:="*", After:=ws.Cells(1, 1), LookIn:=xlFormulas, LookAt:= _
xlPart, SearchOrder:=xlByColumns, SearchDirection:=xlPrevious, MatchCase:=False)

MsgBox ("The last used column is: " & rLastCell.Column)

If you want to find the last column used in a particular row you can use:

Dim lColumn As Long

lColumn = ws.Cells(1, Columns.Count).End(xlToLeft).Column

Using used range (less reliable):

Dim lColumn As Long

lColumn = ws.UsedRange.Columns.Count

Using used range wont work if you have no data in column A. See here for another issue with used range:

See Here regarding resetting used range.

How to add Certificate Authority file in CentOS 7

Maybe late to the party but in my case it was RHEL 6.8:

Copy certificate.crt issued by hosting to:

/etc/pki/ca-trust/source/anchors/

Then:

update-ca-trust force-enable (ignore not found warnings)
update-ca-trust extract

Hope it helps

Select from multiple tables without a join?

You could try something like this:

SELECT ...
FROM (
    SELECT f1,f2,f3 FROM table1
    UNION
    SELECT f1,f2,f3 FROM table2
)
WHERE ...

Performance differences between ArrayList and LinkedList

ArrayList

  • ArrayList is best choice if our frequent operation is retrieval operation.
  • ArrayList is worst choice if our operation is insertion and deletion in the middle because internally several shift operations are performed.
  • In ArrayList elements will be stored in consecutive memory locations hence retrieval operation will become easy.

LinkedList:-

  • LinkedList is best choice if our frequent operation is insertion and deletion in the middle.
  • LinkedList is worst choice is our frequent operation is retrieval operation.
  • In LinkedList the elements won't be stored in consecutive memory location and hence retrieval operation will be complex.

Now coming to your questions:-

1) ArrayList saves data according to indexes and it implements RandomAccess interface which is a marker interface that provides the capability of a Random retrieval to ArrayList but LinkedList doesn't implements RandomAccess Interface that's why ArrayList is faster than LinkedList.

2) The underlying data structure for LinkedList is doubly linked list so insertion and deletion in the middle is very easy in LinkedList as it doesn't have to shift each and every element for each and every deletion and insertion operations just like ArrayList(which is not recommended if our operation is insertion and deletion in the middle because internally several shift operations are performed).
Source

Python CSV error: line contains NULL byte

data_initial = open("staff.csv", "rb")
data = csv.reader((line.replace('\0','') for line in data_initial), delimiter=",")

This works for me.

Replace an element into a specific position of a vector

vec1[i] = vec2[i]

will set the value of vec1[i] to the value of vec2[i]. Nothing is inserted. Your second approach is almost correct. Instead of +i+1 you need just +i

v1.insert(v1.begin()+i, v2[i])

How do I run a shell script without using "sh" or "bash" commands?

You can type sudo install (name of script) /usr/local/bin/(what you want to type to execute said script)

ex: sudo install quickcommit.sh /usr/local/bin/quickcommit enter password

now can run without .sh and in any directory

SQL Server IIF vs CASE

IIF is a non-standard T-SQL function. It was added to SQL SERVER 2012, so that Access could migrate to SQL Server without refactoring the IIF's to CASE before hand. Once the Access db is fully migrated into SQL Server, you can refactor.

What is the lifetime of a static variable in a C++ function?

The existing explanations aren't really complete without the actual rule from the Standard, found in 6.7:

The zero-initialization of all block-scope variables with static storage duration or thread storage duration is performed before any other initialization takes place. Constant initialization of a block-scope entity with static storage duration, if applicable, is performed before its block is first entered. An implementation is permitted to perform early initialization of other block-scope variables with static or thread storage duration under the same conditions that an implementation is permitted to statically initialize a variable with static or thread storage duration in namespace scope. Otherwise such a variable is initialized the first time control passes through its declaration; such a variable is considered initialized upon the completion of its initialization. If the initialization exits by throwing an exception, the initialization is not complete, so it will be tried again the next time control enters the declaration. If control enters the declaration concurrently while the variable is being initialized, the concurrent execution shall wait for completion of the initialization. If control re-enters the declaration recursively while the variable is being initialized, the behavior is undefined.

Rounded Corners Image in Flutter

Use ClipRRect with set image property of fit: BoxFit.fill

ClipRRect(
          borderRadius: new BorderRadius.circular(10.0),
          child: Image(
            fit: BoxFit.fill,
            image: AssetImage('images/image.png'),
            width: 100.0,
            height: 100.0,
          ),
        ),

How to position absolute inside a div?

The absolute divs are taken out of the flow of the document so the containing div does not have any content except for the padding. Give #box a height to fill it out.

#box {
    background-color: #000;
    position: relative;
    padding: 10px;
    width: 220px;
    height:30px;
}

operator << must take exactly one argument

If you define operator<< as a member function it will have a different decomposed syntax than if you used a non-member operator<<. A non-member operator<< is a binary operator, where a member operator<< is a unary operator.

// Declarations
struct MyObj;
std::ostream& operator<<(std::ostream& os, const MyObj& myObj);

struct MyObj
{
    // This is a member unary-operator, hence one argument
    MyObj& operator<<(std::ostream& os) { os << *this; return *this; }

    int value = 8;
};

// This is a non-member binary-operator, 2 arguments
std::ostream& operator<<(std::ostream& os, const MyObj& myObj)
{
    return os << myObj.value;
}

So.... how do you really call them? Operators are odd in some ways, I'll challenge you to write the operator<<(...) syntax in your head to make things make sense.

MyObj mo;

// Calling the unary operator
mo << std::cout;

// which decomposes to...
mo.operator<<(std::cout);

Or you could attempt to call the non-member binary operator:

MyObj mo;

// Calling the binary operator
std::cout << mo;

// which decomposes to...
operator<<(std::cout, mo);

You have no obligation to make these operators behave intuitively when you make them into member functions, you could define operator<<(int) to left shift some member variable if you wanted to, understand that people may be a bit caught off guard, no matter how many comments you may write.

Almost lastly, there may be times where both decompositions for an operator call are valid, you may get into trouble here and we'll defer that conversation.

Lastly, note how odd it might be to write a unary member operator that is supposed to look like a binary operator (as you can make member operators virtual..... also attempting to not devolve and run down this path....)

struct MyObj
{
    // Note that we now return the ostream
    std::ostream& operator<<(std::ostream& os) { os << *this; return os; }

    int value = 8;
};

This syntax will irritate many coders now....

MyObj mo;

mo << std::cout << "Words words words";

// this decomposes to...
mo.operator<<(std::cout) << "Words words words";

// ... or even further ...
operator<<(mo.operator<<(std::cout), "Words words words");

Note how the cout is the second argument in the chain here.... odd right?

Pagination using MySQL LIMIT, OFFSET

Use .. LIMIT :pageSize OFFSET :pageStart

Where :pageStart is bound to the_page_index (i.e. 0 for the first page) * number_of_items_per_pages (e.g. 4) and :pageSize is bound to number_of_items_per_pages.

To detect for "has more pages", either use SQL_CALC_FOUND_ROWS or use .. LIMIT :pageSize OFFSET :pageStart + 1 and detect a missing last (pageSize+1) record. Needless to say, for pages with an index > 0, there exists a previous page.

If the page index value is embedded in the URL (e.g. in "prev page" and "next page" links) then it can be obtained via the appropriate $_GET item.

How to copy files between two nodes using ansible

I was able to solve this using local_action to scp to file from machineA to machineC and then copying the file to machineB.

How to add double quotes to a string that is inside a variable?

"<i class=\"fa fa-check-circle\"></i>" is used with ternary operator with Eval() data binding:

Text = '<%# Eval("bqtStatus").ToString()=="Verified" ? 
       Convert.ToString("<i class=\"fa fa-check-circle\"></i>") : 
       Convert.ToString("<i class=\"fa fa-info-circle\"></i>"

How do I sort a list of datetime or date objects?

You're getting None because list.sort() it operates in-place, meaning that it doesn't return anything, but modifies the list itself. You only need to call a.sort() without assigning it to a again.

There is a built in function sorted(), which returns a sorted version of the list - a = sorted(a) will do what you want as well.

How to remove all MySQL tables from the command-line without DROP database permissions?

You can generate statement like this: DROP TABLE t1, t2, t3, ... and then use prepared statements to execute it:

SET FOREIGN_KEY_CHECKS = 0; 
SET @tables = NULL;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name, '`') INTO @tables
  FROM information_schema.tables 
  WHERE table_schema = 'database_name'; -- specify DB name here.

SET @tables = CONCAT('DROP TABLE ', @tables);
PREPARE stmt FROM @tables;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET FOREIGN_KEY_CHECKS = 1; 

Access denied for root user in MySQL command-line

this might help on Ubuntu:

go to /etc/mysql/my.cnf and comment this line:

bind-address           = 127.0.0.1

Hope this helps someone, I've been searching for this a while too

Cheers

Merge two rows in SQL

There might be neater methods, but the following could be one approach:

SELECT    t.fk,
          (
             SELECT t1.Field1 
             FROM   `table` t1 
             WHERE  t1.fk = t.fk AND t1.Field1 IS NOT NULL
             LIMIT  1
          ) Field1,
          (
             SELECT t2.Field2
             FROM   `table` t2 
             WHERE  t2.fk = t.fk AND t2.Field2 IS NOT NULL
             LIMIT  1
          ) Field2
FROM      `table` t
WHERE     t.fk = 3
GROUP BY  t.fk;

Test Case:

CREATE TABLE `table` (fk int, Field1 varchar(10), Field2 varchar(10));

INSERT INTO `table` VALUES (3, 'ABC', NULL);
INSERT INTO `table` VALUES (3, NULL, 'DEF');
INSERT INTO `table` VALUES (4, 'GHI', NULL);
INSERT INTO `table` VALUES (4, NULL, 'JKL');
INSERT INTO `table` VALUES (5, NULL, 'MNO');

Result:

+------+--------+--------+
| fk   | Field1 | Field2 |
+------+--------+--------+
|    3 | ABC    | DEF    |
+------+--------+--------+
1 row in set (0.01 sec)

Running the same query without the WHERE t.fk = 3 clause, it would return the following result-set:

+------+--------+--------+
| fk   | Field1 | Field2 |
+------+--------+--------+
|    3 | ABC    | DEF    |
|    4 | GHI    | JKL    |
|    5 | NULL   | MNO    |
+------+--------+--------+
3 rows in set (0.01 sec)

Using OR & AND in COUNTIFS

i found i had to do something akin to

=(countifs (A1:A196,"yes", j1:j196, "agree") + (countifs (A1:A196,"no", j1:j196, "agree"))

How to make bootstrap 3 fluid layout without horizontal scrollbar

Apply to the body seems to get rid of the horizontal scrollbar

overflow-x: hidden;

Replace values in list using Python

ls = [x if (condition) else None for x in ls]

How to get the index of an item in a list in a single step?

If anyone wonders for the Array version, it goes like this:

int i = Array.FindIndex(yourArray, x => x == itemYouWant);

Center a column using Twitter Bootstrap 3

Try this code.

<body class="container">
    <div class="col-lg-1 col-lg-offset-10">
        <img data-src="holder.js/100x100" alt="" />
    </div>
</body>

Here I have used col-lg-1, and the offset should be 10 for properly centered the div on large devices. If you need it to center on medium-to-large devices then just change the lg to md and so on.

Convert an int to ASCII character

I suppose that

std::to_string(i)

could do the job, it's an overloaded function, it could be any numeric type such as int, double or float

How do I generate a random integer between min and max in Java?

Construct a Random object at application startup:

Random random = new Random();

Then use Random.nextInt(int):

int randomNumber = random.nextInt(max + 1 - min) + min;

Note that the both lower and upper limits are inclusive.

SQL - select distinct only on one column

Since you don't care, I chose the max ID for each number.

select tbl.* from tbl
inner join (
select max(id) as maxID, number from tbl group by number) maxID
on maxID.maxID = tbl.id

Query Explanation

 select 
    tbl.*  -- give me all the data from the base table (tbl) 
 from 
    tbl    
    inner join (  -- only return rows in tbl which match this subquery
        select 
            max(id) as maxID -- MAX (ie distinct) ID per GROUP BY below
        from 
            tbl 
        group by 
            NUMBER            -- how to group rows for the MAX aggregation
    ) maxID
        on maxID.maxID = tbl.id -- join condition ie only return rows in tbl 
                                -- whose ID is also a MAX ID for a given NUMBER

How to avoid "Permission denied" when using pip with virtualenv

I didn't create my virtualenv using sudo. So Sebastian's answer didn't apply to me. My project is called utils. I checked utils directory and saw this:

-rw-r--r--   1 macuser  staff   983  6 Jan 15:17 README.md
drwxr-xr-x   6 root     staff   204  6 Jan 14:36 utils.egg-info
-rw-r--r--   1 macuser  staff    31  6 Jan 15:09 requirements.txt

As you can see, utils.egg-info is owned by root not macuser. That is why it was giving me permission denied error. I also had to remove /Users/macuser/.virtualenvs/armoury/lib/python2.7/site-packages/utils.egg-link as it was created by root as well. I did pip install -e . again after removing those, and it worked.

ios Upload Image and Text using HTTP POST

Here is a Swift version. Note that if you do not want to send form data it is still important to send the empty form boundary. Flask in particular expects form data followed by file data and will not populate request.files without the first boundary.

  let composedData = NSMutableData()

  // Set content type header
  let BoundaryConstant = "--------------------------3d74a90a3bfb8696"
  let contentType = "multipart/form-data; boundary=\(BoundaryConstant)"
  request.setValue(contentType, forHTTPHeaderField: "Content-Type")

  // Empty form boundary
  composedData.appendData("--\(BoundaryConstant)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

  // Build multipart form to send image
  composedData.appendData("--\(BoundaryConstant)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("Content-Disposition: form-data; name=\"file\"; filename=\"image.jpg\"\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("Content-Type: image/jpeg\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData(rawData!)
  composedData.appendData("\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("--\(BoundaryConstant)--\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

  request.HTTPBody = composedData

  // Get content length
  let length = "\(composedData.length)"
  request.setValue(length, forHTTPHeaderField: "Content-Length")

SQL MERGE statement to update data

THE CORRECT WAY IS :

UPDATE test1
INNER JOIN test2 ON (test1.id = test2.id)
SET test1.data = test2.data

Html/PHP - Form - Input as array

HTML: Use names as

<input name="levels[level][]">
<input name="levels[build_time][]">

PHP:

$array = filter_input_array(INPUT_POST);
$newArray = array();
foreach (array_keys($array) as $fieldKey) {
    foreach ($array[$fieldKey] as $key=>$value) {
        $newArray[$key][$fieldKey] = $value;
    }
}  

$newArray will hold data as you want

Array ( 
  [0] => Array ( [level] => 1 [build_time] => 123 ) 
  [1] => Array ( [level] => 2 [build_time] => 456 )
)