Programs & Examples On #.class file

Class files are the format used by the Java Virtual Machine.

How can I compile a Java program in Eclipse without running it?

Right click on Yourproject(in project Explorer)-->Build Project

It will compile all files in your project and updates your build folder, all without running.

How to change already compiled .class file without decompile?

Sometime we need to compile one single file out of thousand files to fix the problem. In such a case, One can create same folder structure like class path, decompile the file into java or copy java file from source code. Make required changes, compile one particular file into class with all dependency/classes in place and finally replace the class file. Finally restart the container. Once war is exploded file will not be replaced.

How to group an array of objects by key

function groupBy(data, property) {
  return data.reduce((acc, obj) => {
    const key = obj[property];
    if (!acc[key]) {
      acc[key] = [];
    }
    acc[key].push(obj);
    return acc;
  }, {});
}
groupBy(people, 'age');

Get Maven artifact version at runtime

To follow up the answer above, for a .war artifact, I found I had to apply the equivalent configuration to maven-war-plugin, rather than maven-jar-plugin:

<plugin>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.1</version>
    <configuration>
        <archive>                   
            <manifest>
                <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
            </manifest>
        </archive>
    </configuration>
</plugin>

This added the version information to MANIFEST.MF in the project's .jar (included in WEB-INF/lib of the .war)

How to type a new line character in SQL Server Management Studio

Either char(13) or char(10) would work. But it is recommended to use char(13) + char(10)

  • char(10) = \n - new line
  • char(13) = \r - go to the beginning of the line

How to copy directory recursively in python and overwrite all?

In Python 3.8 the dirs_exist_ok keyword argument was added to shutil.copytree():

dirs_exist_ok dictates whether to raise an exception in case dst or any missing parent directory already exists.

So, the following will work in recent versions of Python, even if the destination directory already exists:

shutil.copytree(src, dest, dirs_exist_ok=True)  # 3.8+ only!

One major benefit is that it's more flexible than distutils.dir_util.copy_tree() as it takes additional arguments on files to ignore, etc. There is also a draft PEP (PEP 632, associated discussion), which suggests that distutils may be deprecated and then removed in future versions of Python 3.

Row count with PDO

A quick one liner to get the first entry returned. This is nice for very basic queries.

<?php
$count = current($db->query("select count(*) from table")->fetch());
?>

Reference

100% width in React Native Flexbox

Style ={{width : "100%"}}

try this:

StyleSheet generated: {
  "width": "80%",
  "textAlign": "center",
  "marginTop": 21.8625,
  "fontWeight": "bold",
  "fontSize": 16,
  "color": "rgb(24, 24, 24)",
  "fontFamily": "Trajan Pro",
  "textShadowColor": "rgba(255, 255, 255, 0.2)",
  "textShadowOffset": {
    "width": 0,
    "height": 0.5
  }
}

Java properties UTF-8 encoding in Eclipse

If the properties are for XML or HTML, it's safest to use XML entities. They're uglier to read, but it means that the properties file can be treated as straight ASCII, so nothing will get mangled.

Note that HTML has entities that XML doesn't, so I keep it safe by using straight XML: http://www.w3.org/TR/html4/sgml/entities.html

How does @synchronized lock/unlock in Objective-C?

Actually

{
  @synchronized(self) {
    return [[myString retain] autorelease];
  }
}

transforms directly into:

// needs #import <objc/objc-sync.h>
{
  objc_sync_enter(self)
    id retVal = [[myString retain] autorelease];
  objc_sync_exit(self);
  return retVal;
}

This API available since iOS 2.0 and imported using...

#import <objc/objc-sync.h>

Send XML data to webservice using php curl

After Struggling a bit with Arzoo International flight API, I've finally found the solution and the code simply works absolutely great with me. Here are the complete working code:

//Store your XML Request in a variable
    $input_xml = '<AvailRequest>
            <Trip>ONE</Trip>
            <Origin>BOM</Origin>
            <Destination>JFK</Destination>
            <DepartDate>2013-09-15</DepartDate>
            <ReturnDate>2013-09-16</ReturnDate>
            <AdultPax>1</AdultPax>
            <ChildPax>0</ChildPax>
            <InfantPax>0</InfantPax>
            <Currency>INR</Currency>
            <PreferredClass>E</PreferredClass>
            <Eticket>true</Eticket>
            <Clientid>777ClientID</Clientid>
            <Clientpassword>*Your API Password</Clientpassword>
            <Clienttype>ArzooINTLWS1.0</Clienttype>
            <PreferredAirline></PreferredAirline>
    </AvailRequest>';

Now I've made a little changes in the above curl_setopt declaration as follows:

    $url = "http://59.162.33.102:9301/Avalability";

        //setting the curl parameters.
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
// Following line is compulsary to add as it is:
        curl_setopt($ch, CURLOPT_POSTFIELDS,
                    "xmlRequest=" . $input_xml);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 300);
        $data = curl_exec($ch);
        curl_close($ch);

        //convert the XML result into array
        $array_data = json_decode(json_encode(simplexml_load_string($data)), true);

        print_r('<pre>');
        print_r($array_data);
        print_r('</pre>');

That's it the code works absolutely fine for me. I really appreciate @hakre & @Lucas For their wonderful support.

Import text file as single character string

It seems your solution is not much ugly. You can use functions and make it proffesional like these ways

  • first way
new.function <- function(filename){
  readChar(filename, file.info(filename)$size)
}

new.function('foo.txt')
  • second way
new.function <- function(){
  filename <- 'foo.txt'
  return (readChar(filename, file.info(filename)$size))
}

new.function()

Should I always use a parallel stream when possible?

The Stream API was designed to make it easy to write computations in a way that was abstracted away from how they would be executed, making switching between sequential and parallel easy.

However, just because its easy, doesn't mean its always a good idea, and in fact, it is a bad idea to just drop .parallel() all over the place simply because you can.

First, note that parallelism offers no benefits other than the possibility of faster execution when more cores are available. A parallel execution will always involve more work than a sequential one, because in addition to solving the problem, it also has to perform dispatching and coordinating of sub-tasks. The hope is that you'll be able to get to the answer faster by breaking up the work across multiple processors; whether this actually happens depends on a lot of things, including the size of your data set, how much computation you are doing on each element, the nature of the computation (specifically, does the processing of one element interact with processing of others?), the number of processors available, and the number of other tasks competing for those processors.

Further, note that parallelism also often exposes nondeterminism in the computation that is often hidden by sequential implementations; sometimes this doesn't matter, or can be mitigated by constraining the operations involved (i.e., reduction operators must be stateless and associative.)

In reality, sometimes parallelism will speed up your computation, sometimes it will not, and sometimes it will even slow it down. It is best to develop first using sequential execution and then apply parallelism where

(A) you know that there's actually benefit to increased performance and

(B) that it will actually deliver increased performance.

(A) is a business problem, not a technical one. If you are a performance expert, you'll usually be able to look at the code and determine (B), but the smart path is to measure. (And, don't even bother until you're convinced of (A); if the code is fast enough, better to apply your brain cycles elsewhere.)

The simplest performance model for parallelism is the "NQ" model, where N is the number of elements, and Q is the computation per element. In general, you need the product NQ to exceed some threshold before you start getting a performance benefit. For a low-Q problem like "add up numbers from 1 to N", you will generally see a breakeven between N=1000 and N=10000. With higher-Q problems, you'll see breakevens at lower thresholds.

But the reality is quite complicated. So until you achieve experthood, first identify when sequential processing is actually costing you something, and then measure if parallelism will help.

How to empty a char array?

using

  memset(members, 0, 255);

in general

  memset(members, 0, sizeof members);

if the array is in scope, or

  memset(members, 0, nMembers * (sizeof members[0]) );

if you only have the pointer value, and nMembers is the number of elements in the array.


EDIT Of course, now the requirement has changed from the generic task of clearing an array to purely resetting a string, memset is overkill and just zeroing the first element suffices (as noted in other answers).


EDIT In order to use memset, you have to include string.h.

Undefined reference to `sin`

You have compiled your code with references to the correct math.h header file, but when you attempted to link it, you forgot the option to include the math library. As a result, you can compile your .o object files, but not build your executable.

As Paul has already mentioned add "-lm" to link with the math library in the step where you are attempting to generate your executable.

In the comment, linuxD asks:

Why for sin() in <math.h>, do we need -lm option explicitly; but, not for printf() in <stdio.h>?

Because both these functions are implemented as part of the "Single UNIX Specification". This history of this standard is interesting, and is known by many names (IEEE Std 1003.1, X/Open Portability Guide, POSIX, Spec 1170).

This standard, specifically separates out the "Standard C library" routines from the "Standard C Mathematical Library" routines (page 277). The pertinent passage is copied below:

Standard C Library

The Standard C library is automatically searched by cc to resolve external references. This library supports all of the interfaces of the Base System, as defined in Volume 1, except for the Math Routines.

Standard C Mathematical Library

This library supports the Base System math routines, as defined in Volume 1. The cc option -lm is used to search this library.

The reasoning behind this separation was influenced by a number of factors:

  1. The UNIX wars led to increasing divergence from the original AT&T UNIX offering.
  2. The number of UNIX platforms added difficulty in developing software for the operating system.
  3. An attempt to define the lowest common denominator for software developers was launched, called 1988 POSIX.
  4. Software developers programmed against the POSIX standard to provide their software on "POSIX compliant systems" in order to reach more platforms.
  5. UNIX customers demanded "POSIX compliant" UNIX systems to run the software.

The pressures that fed into the decision to put -lm in a different library probably included, but are not limited to:

  1. It seems like a good way to keep the size of libc down, as many applications don't use functions embedded in the math library.
  2. It provides flexibility in math library implementation, where some math libraries rely on larger embedded lookup tables while others may rely on smaller lookup tables (computing solutions).
  3. For truly size constrained applications, it permits reimplementations of the math library in a non-standard way (like pulling out just sin() and putting it in a custom built library.

In any case, it is now part of the standard to not be automatically included as part of the C language, and that's why you must add -lm.

Installation failed with message Invalid File

Click Build tab ---> Clean Project

Click Build tab ---> Build APK

Run.

Getting selected value of a combobox

You have to cast the selected item to your custom class (ComboboxItem) Try this:

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox cmb = (ComboBox)sender;
            int selectedIndex = cmb.SelectedIndex;
            string selectedText = this.comboBox1.Text;
            string selectedValue = ((ComboboxItem)cmb.SelectedItem).Value.ToString();

ComboboxItem selectedCar = (ComboboxItem)cmb.SelectedItem;
MessageBox.Show(String.Format("Index: [{0}] CarName={1}; Value={2}", selectedIndex, selectedCar.Text, selecteVal));        

}

App.Config file in console application C#

You can add a reference to System.Configuration in your project and then:

using System.Configuration;

then

string sValue = ConfigurationManager.AppSettings["BatchFile"];

with an app.config file like this:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
   <appSettings>
       <add key="BatchFile" value="blah.bat" />
   </appSettings>
</configuration>

what is the use of Eval() in asp.net

While binding a databound control, you can evaluate a field of the row in your data source with eval() function.

For example you can add a column to your gridview like that :

<asp:BoundField DataField="YourFieldName" />

And alternatively, this is the way with eval :

<asp:TemplateField>
<ItemTemplate>
        <asp:Label ID="lbl" runat="server" Text='<%# Eval("YourFieldName") %>'>
        </asp:Label>
</ItemTemplate>
</asp:TemplateField>

It seems a little bit complex, but it's flexible, because you can set any property of the control with the eval() function :

<asp:TemplateField>
    <ItemTemplate>
        <asp:HyperLink ID="HyperLink1" runat="server" 
          NavigateUrl='<%# "ShowDetails.aspx?id="+Eval("Id") %>' 
          Text='<%# Eval("Text", "{0}") %>'></asp:HyperLink>
    </ItemTemplate>
</asp:TemplateField>

How to import spring-config.xml of one project into spring-config.xml of another project?

<import resource="classpath*:spring-config.xml" /> 

This is the most suitable one for class path configuration. Particularly when you are searching for the .xml files in a different project which is in your class path.

Cassandra cqlsh - connection refused

Had same problem recently after downgrade from Cassandra 3.0 to Cassandra 2.2 on ArchLinux.

Unlike above solutions my problem wasn't in .cassandra, but version 3.0 left its configuration in /var/lib/cassandra directory.

Following commands solved my problem:

sudo rm -R /var/lib/cassandra
sudo rm -R /var/log/cassandra
sudo rm -R /usr/share/cassandra

Then i installed cassandra and everything worked again :)

width:auto for <input> fields

The only option I can think of is using width:100%. If you want to have a padding on the input field too, than just place a container label around it, move the formatting to that label instead, while also specify the padding to the label. Input fields are rigid.

Found shared references to a collection org.hibernate.HibernateException

Consider an entity:

public class Foo{
private<user> user;
/* with getters and setters */
}

And consider an Business Logic class:

class Foo1{
List<User> user = new ArrayList<>();
user = foo.getUser();
}

Here the user and foo.getUser() share the same reference. But saving the two references creates a conflict.

The proper usage should be:

class Foo1 {
List<User> user = new ArrayList<>();
user.addAll(foo.getUser);
}

This avoids the conflict.

Determining Referer in PHP

We have only single option left after reading all the fake referrer problems: i.e. The page we desire to track as referrer should be kept in session, and as ajax called then checking in session if it has referrer page value and doing the action other wise no action.

While on the other hand as he request any different page then make the referrer session value to null.

Remember that session variable is set on desire page request only.

#1273 - Unknown collation: 'utf8mb4_unicode_ci' cPanel

If you are using PHP7, then you would need a PHP script like this one in order to migrate your collation:

<!DOCTYPE html>
<html>
<head>
  <title>DB-Convert</title>
  <style>
    body { font-family:"Courier New", Courier, monospace; }
  </style>
</head>
<body>

<h1>Convert your Database to utf8_general_ci!</h1>

<form action="db-convert.php" method="post">
  dbname: <input type="text" name="dbname"><br>
  dbuser: <input type="text" name="dbuser"><br>
  dbpass: <input type="text" name="dbpassword"><br>
  <input type="submit">
</form>

</body>
</html>
<?php
if ($_POST) {
  $dbname = $_POST['dbname'];
  $dbuser = $_POST['dbuser'];
  $dbpassword = $_POST['dbpassword'];

  $mysqli = new mysqli('db',$dbuser,$dbpassword);
  if ($mysqli -> connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
    exit();
  }
  $mysqli -> select_db($dbname);
  $result= $mysqli->query('show tables');
  while($tables = $result->fetch_array) {
          foreach ($tables as $key => $value) {
           $mysqli->query("ALTER TABLE $value CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci");
     }}
  echo "<script>alert('The collation of your database has been successfully changed!');</script>";
}

?>

Could not reserve enough space for object heap

I know there are a lot of answers here already, but none of them helped me. In the end I opened the file /etc/elasticsearch/jvm.options and changed:

-Xms2G
-Xmx2G

to

-Xms256M
-Xmx256M

That solved it for me. Hopefully this helps someone else here.

What is the command for cut copy paste a file from one directory to other directory

use the xclip which is command line interface to X selections

install

apt-get install xclip

usage

echo "test xclip " > /tmp/test.xclip
xclip -i < /tmp/test.xclip
xclip -o > /tmp/test.xclip.out

cat /tmp/test.xclip.out   # "test xclip"

enjoy.

What is a tracking branch?

TL;DR Remember, all git branches are themselves used for tracking the history of a set of files. Therefore, isn't every branch actually a "tracking branch", because that's what these branches are used for: to track the history of files over time. Thus we should probably be calling normal git "branches", "tracking-branches", but we don't. Instead we shorten their name to just "branches".

So that's partly why the term "tracking-branches" is so terribly confusing: to the uninitiated it can easily mean 2 different things.

In git the term "Tracking-branch" is a short name for the more complete term: "Remote-tracking-branch".

It's probably better at first if you substitute the more formal terms until you get more comfortable with these concepts.

Let's rephrase your question to this:

What is a "Remote-tracking-branch?"

The key word here is 'Remote', so skip down to where you get confused and I'll describe what a Remote Tracking branch is and how it's used.


To better understand git terminology, including branches and tracking, which can initially be very confusing, I think it's easiest if you first get crystal clear on what git is and the basic structure of how it works. Without a solid understand like this I promise you'll get lost in the many details, as git has lots of complexity; (translation: lots of people use it for very important things).

The following is an introduction/overview, but you might find this excellent article also informative.


WHAT GIT IS, AND WHAT IT'S FOR

A git repository is like a family photo album: It holds historical snapshots showing how things were in past times. A "snapshot" being a recording of something, at a given moment in time.

A git repository is not limited to holding human family photos. It, rather can be used to record and organize anything that is evolving or changing over time.

The basic idea is to create a book so we can easily look backwards in time,

  • to compare past times, with now, or other moments in time, and
  • to re-create the past.

When you get mired down in the complexity and terminology, try to remember that a git repository is first and foremost, a repository of snapshots, and just like a photo album, it's used to both store and organize these snapshots.


SNAPSHOTS AND TRACKING

tracked - to follow a person or animal by looking for proof that they have been somewhere (dictionary.cambridge.org)

In git, "your project" refers to a directory tree of files (one or more, possibly organized into a tree structure using sub-directories), which you wish to keep a history of.

Git, via a 3 step process, records a "snapshot" of your project's directory tree at a given moment in time.

Each git snapshot of your project, is then organized by "links" pointing to previous snapshots of your project.

One by one, link-by-link, we can look backwards in time to find any previous snapshot of you, or your heritage.

For example, we can start with today's most recent snapshot of you, and then using a link, seek backwards in time, for a photo of you taken perhaps yesterday or last week, or when you were a baby, or even who your mother was, etc.

This is refereed to as "tracking; in this example it is tracking your life, or seeing where you have left a footprint, and where you have come from.


COMMITS

A commit is similar to one page in your photo album with a single snapshot, in that its not just the snapshot contained there, but also has the associated meta information about that snapshot. It includes:

  • an address or fixed place where we can find this commit, similar to its page number,
  • one snapshot of your project (of your file directory tree) at a given moment in time,
  • a caption or comment saying what the snapshot is of, or for,
  • the date and time of that snapshot,
  • who took the snapshot, and finally,
  • one, or more, links backwards in time to previous, related snapshots like to yesterday's snapshot, or to our parent or parents. In other words "links" are similar to pointers to the page numbers of other, older photos of myself, or when I am born to my immediate parents.

A commit is the most important part of a well organized photo album.


THE FAMILY TREE OVER TIME, WITH BRANCHES AND MERGES

Disambiguation: "Tree" here refers not to a file directory tree, as used above, but rather to a family tree of related parent and child commits over time.

The git family tree structure is modeled on our own, human family trees.

In what follows to help understand links in a simple way, I'll refer to:

  • a parent-commit as simply a "parent", and
  • a child-commit as simply a "child" or "children" if plural.

You should understand this instinctively, as it is based on the tree of life:

  • A parent might have one or more children pointing back in time at them, and
  • children always have one or more parents they point to.

Thus all commits except brand new commits, (you could say "juvenile commits"), have one or more children pointing back at them.

  • With no children are pointing to a parent, then this commit is only a "growing tip", or where the next child will be born from.

  • With just one child pointing at a parent, this is just a simple, single parent <-- child relationship.

Line diagram of a simple, single parent chain linking backwards in time:

(older) ... <--link1-- Commit1 <--link2-- Commit2 <--link3-- Commit3 (newest)

BRANCHES

branch - A "branch" is an active line of development. The most recent commit on a branch is referred to as the tip of that branch. The tip of the branch is referenced by a branch head, which moves forward as additional development is done on the branch. A single Git repository can track an arbitrary number of branches, but your working tree is associated with just one of them (the "current" or "checked out" branch), and HEAD points to that branch. (gitglossary)

A git branch also refers to two things:

  • a name given to a growing tip, (an identifier), and
  • the actual branch in the graph of links between commits.

More than one child pointing --at a--> parent, is what git calls "branching".

NOTE: In reality any child, of any parent, weather first, second, or third, etc., can be seen as their own little branch, with their own growing tip. So a branch is not necessarily a long thing with many nodes, rather it is a little thing, created with just one or more commits from a given parent.

The first child of a parent might be said to be part of that same branch, whereas the successive children of that parent are what are normally called "branches".

In actuality, all children (not just the first) branch from it's parent, or you could say link, but I would argue that each link is actually the core part of a branch.

Formally, a git "branch" is just a name, like 'foo' for example, given to a specific growing tip of a family hierarchy. It's one type of what they call a "ref". (Tags and remotes which I'll explain later are also refs.)

ref - A name that begins with refs/ (e.g. refs/heads/master) that points to an object name or another ref (the latter is called a symbolic ref). For convenience, a ref can sometimes be abbreviated when used as an argument to a Git command; see gitrevisions(7) for details. Refs are stored in the repository.

The ref namespace is hierarchical. Different subhierarchies are used for different purposes (e.g. the refs/heads/ hierarchy is used to represent local branches). There are a few special-purpose refs that do not begin with refs/. The most notable example is HEAD. (gitglossary)

(You should take a look at the file tree inside your .git directory. It's where the structure of git is saved.)

So for example, if your name is Tom, then commits linked together that only include snapshots of you, might be the branch we name "Tom".

So while you might think of a tree branch as all of it's wood, in git a branch is just a name given to it's growing tips, not to the whole stick of wood leading up to it.

The special growing tip and it's branch which an arborist (a guy who prunes fruit trees) would call the "central leader" is what git calls "master".

The master branch always exists.

Line diagram of: Commit1 with 2 children (or what we call a git "branch"):

                parent      children

                        +-- Commit <-- Commit <-- Commit (Branch named 'Tom')
                       /
                      v
(older) ... <-- Commit1 <-- Commit                       (Branch named 'master')    

Remember, a link only points from child to parent. There is no link pointing the other way, i.e. from old to new, that is from parent to child.

So a parent-commit has no direct way to list it's children-commits, or in other words, what was derived from it.


MERGING

Children have one or more parents.

  • With just one parent this is just a simple parent <-- child commit.

  • With more than one parent this is what git calls "merging". Each child can point back to more than one parent at the same time, just as in having both a mother AND father, not just a mother.

Line diagram of: Commit2 with 2 parents (or what we call a git "merge", i.e. Procreation from multiple parents):

                parents     child

           ... <-- Commit
                        v
                         \
(older) ... <-- Commit1 <-- Commit2  

REMOTE

This word is also used to mean 2 different things:

  • a remote repository, and
  • the local alias name for a remote repository, i.e. a name which points using a URL to a remote repository.

remote repository - A repository which is used to track the same project but resides somewhere else. To communicate with remotes, see fetch or push. (gitglossary)

(The remote repository can even be another git repository on our own computer.) Actually there are two URLS for each remote name, one for pushing (i.e. uploading commits) and one for pulling (i.e. downloading commits) from that remote git repository.

A "remote" is a name (an identifier) which has an associated URL which points to a remote git repository. (It's been described as an alias for a URL, although it's more than that.)

You can setup multiple remotes if you want to pull or push to multiple remote repositories.

Though often you have just one, and it's default name is "origin" (meaning the upstream origin from where you cloned).

origin - The default upstream repository. Most projects have at least one upstream project which they track. By default origin is used for that purpose. New upstream updates will be fetched into remote-tracking branches named origin/name-of-upstream-branch, which you can see using git branch -r. (gitglossary)

Origin represents where you cloned the repository from.
That remote repository is called the "upstream" repository, and your cloned repository is called the "downstream" repository.

upstream - In software development, upstream refers to a direction toward the original authors or maintainers of software that is distributed as source code wikipedia

upstream branch - The default branch that is merged into the branch in question (or the branch in question is rebased onto). It is configured via branch..remote and branch..merge. If the upstream branch of A is origin/B sometimes we say "A is tracking origin/B". (gitglossary)

This is because most of the water generally flows down to you.
From time to time you might push some software back up to the upstream repository, so it can then flow down to all who have cloned it.

REMOTE TRACKING BRANCH

A remote-tracking-branch is first, just a branch name, like any other branch name.

It points at a local growing tip, i.e. a recent commit in your local git repository.

But note that it effectively also points to the same commit in the remote repository that you cloned the commit from.

remote-tracking branch - A ref that is used to follow changes from another repository. It typically looks like refs/remotes/foo/bar (indicating that it tracks a branch named bar in a remote named foo), and matches the right-hand-side of a configured fetch refspec. A remote-tracking branch should not contain direct modifications or have local commits made to it. (gitglossary)

Say the remote you cloned just has 2 commits, like this: parent42 <== child-of-4, and you clone it and now your local git repository has the same exact two commits: parent4 <== child-of-4.
Your remote tracking branch named origin now points to child-of-4.

Now say that a commit is added to the remote, so it looks like this: parent42 <== child-of-4 <== new-baby. To update your local, downstream repository you'll need to fetch new-baby, and add it to your local git repository. Now your local remote-tracking-branch points to new-baby. You get the idea, the concept of a remote-tracking-branch is simply to keep track of what had previously been the tip of a remote branch that you care about.


TRACKING IN ACTION

First we begin tracking a file with git.

enter image description here

Here are the basic commands involved with file tracking:

$ mkdir mydir &&  cd mydir &&  git init             # create a new git repository

$ git branch                                        # this initially reports no branches
                                                    #  (IMHO this is a bug!)

$ git status -bs       # -b = branch; -s = short    # master branch is empty
## No commits yet on master

# ...
$ touch foo                                         # create a new file

$ vim foo                                           # modify it (OPTIONAL)


$ git add         foo; commit -m 'your description'  # start tracking foo 
$ git rm  --index foo; commit -m 'your description'  # stop  tracking foo 
$ git rm          foo; commit -m 'your description'  # stop  tracking foo & also delete foo

REMOTE TRACKING IN ACTION

$ git pull    # Essentially does:  get fetch; git merge    # to update our clone

There is much more to learn about fetch, merge, etc, but this should get you off in the right direction I hope.

rails simple_form - hidden field - create?

= f.input_field :title, as: :hidden, value: "some value"

Is also an option. Note, however, that it skips any wrapper defined for your form builder.

PRINT statement in T-SQL

Query Analyzer buffers messages. The PRINT and RAISERROR statements both use this buffer, but the RAISERROR statement has a WITH NOWAIT option. To print a message immediately use the following:

RAISERROR ('Your message', 0, 1) WITH NOWAIT

RAISERROR will only display 400 characters of your message and uses a syntax similar to the C printf function for formatting text.

Please note that the use of RAISERROR with the WITH NOWAIT option will flush the message buffer, so all previously buffered information will be output also.

Drop rows containing empty cells from a pandas DataFrame

Pythonic + Pandorable: df[df['col'].astype(bool)]

Empty strings are falsy, which means you can filter on bool values like this:

df = pd.DataFrame({
    'A': range(5),
    'B': ['foo', '', 'bar', '', 'xyz']
})
df
   A    B
0  0  foo
1  1     
2  2  bar
3  3     
4  4  xyz
df['B'].astype(bool)                                                                                                                      
0     True
1    False
2     True
3    False
4     True
Name: B, dtype: bool

df[df['B'].astype(bool)]                                                                                                                  
   A    B
0  0  foo
2  2  bar
4  4  xyz

If your goal is to remove not only empty strings, but also strings only containing whitespace, use str.strip beforehand:

df[df['B'].str.strip().astype(bool)]
   A    B
0  0  foo
2  2  bar
4  4  xyz

Faster than you Think

.astype is a vectorised operation, this is faster than every option presented thus far. At least, from my tests. YMMV.

Here is a timing comparison, I've thrown in some other methods I could think of.

enter image description here

Benchmarking code, for reference:

import pandas as pd
import perfplot

df1 = pd.DataFrame({
    'A': range(5),
    'B': ['foo', '', 'bar', '', 'xyz']
})

perfplot.show(
    setup=lambda n: pd.concat([df1] * n, ignore_index=True),
    kernels=[
        lambda df: df[df['B'].astype(bool)],
        lambda df: df[df['B'] != ''],
        lambda df: df[df['B'].replace('', np.nan).notna()],  # optimized 1-col
        lambda df: df.replace({'B': {'': np.nan}}).dropna(subset=['B']),  
    ],
    labels=['astype', "!= ''", "replace + notna", "replace + dropna", ],
    n_range=[2**k for k in range(1, 15)],
    xlabel='N',
    logx=True,
    logy=True,
    equality_check=pd.DataFrame.equals)

Call JavaScript function on DropDownList SelectedIndexChanged Event:

First Method: (Tested)

Code in .aspx.cs:

 protected void Page_Load(object sender, EventArgs e)
    {
        ddl.SelectedIndexChanged += new EventHandler(ddl_SelectedIndexChanged);
        if (!Page.IsPostBack)
        {
            ddl.Attributes.Add("onchange", "CalcTotalAmt();");
        }
    }

    protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
    {
       //Your Code
    }

JavaScript function: return true from your JS function

   function CalcTotalAmt() 
 {
//Your Code
 }

.aspx code:

<asp:DropDownList ID="ddl" runat="server"  AutoPostBack="true">
        <asp:ListItem Text="a" Value="a"></asp:ListItem>
         <asp:ListItem Text="b" Value="b"></asp:ListItem>
        </asp:DropDownList>

Second Method: (Tested)

Code in .aspx.cs:

protected void Page_Load(object sender, EventArgs e)
        {
            if (Request.Params["__EVENTARGUMENT"] != null && Request.Params["__EVENTARGUMENT"].Equals("ddlchange"))
                ddl_SelectedIndexChanged(sender, e);
            if (!Page.IsPostBack)
            {
                ddl.Attributes.Add("onchange", "CalcTotalAmt();");
            }
        }

        protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
        {
            //Your Code
        }

JavaScript function: return true from your JS function

function CalcTotalAmt() {
         //Your Code
     __doPostBack("ctl00$MainContent$ddl","ddlchange");
 }

.aspx code:

<asp:DropDownList ID="ddl" runat="server"  AutoPostBack="true">
        <asp:ListItem Text="a" Value="a"></asp:ListItem>
         <asp:ListItem Text="b" Value="b"></asp:ListItem>
        </asp:DropDownList>

Curl to return http status code along with the response

This is a way to retrieve the body "AND" the status code and format it to a proper json or whatever format works for you. Some may argue it's the incorrect use of write format option but this works for me when I need both body and status code in my scripts to check status code and relay back the responses from server.

curl -X GET -w "%{stderr}{\"status\": \"%{http_code}\", \"body\":\"%{stdout}\"}"  -s -o - “https://github.com” 2>&1

run the code above and you should get back a json in this format:

{
"status" : <status code>,
"body" : <body of response>
}

with the -w write format option, since stderr is printed first, you can format your output with the var http_code and place the body of the response in a value (body) and follow up the enclosing using var stdout. Then redirect your stderr output to stdout and you'll be able to combine both http_code and response body into a neat output

Java compiler level does not match the version of the installed Java project facet

In Eclipse, right click on your project, go to Maven> Update projetc. Wait and the error will disappear. This is already configured correctly the version of Java for this project.

enter image description here

Use of Custom Data Types in VBA

Sure you can:

Option Explicit

'***** User defined type
Public Type MyType
     MyInt As Integer
     MyString As String
     MyDoubleArr(2) As Double
End Type

'***** Testing MyType as single variable
Public Sub MyFirstSub()
    Dim MyVar As MyType

    MyVar.MyInt = 2
    MyVar.MyString = "cool"
    MyVar.MyDoubleArr(0) = 1
    MyVar.MyDoubleArr(1) = 2
    MyVar.MyDoubleArr(2) = 3

    Debug.Print "MyVar: " & MyVar.MyInt & " " & MyVar.MyString & " " & MyVar.MyDoubleArr(0) & " " & MyVar.MyDoubleArr(1) & " " & MyVar.MyDoubleArr(2)
End Sub

'***** Testing MyType as an array
Public Sub MySecondSub()
    Dim MyArr(2) As MyType
    Dim i As Integer

    MyArr(0).MyInt = 31
    MyArr(0).MyString = "VBA"
    MyArr(0).MyDoubleArr(0) = 1
    MyArr(0).MyDoubleArr(1) = 2
    MyArr(0).MyDoubleArr(2) = 3
    MyArr(1).MyInt = 32
    MyArr(1).MyString = "is"
    MyArr(1).MyDoubleArr(0) = 11
    MyArr(1).MyDoubleArr(1) = 22
    MyArr(1).MyDoubleArr(2) = 33
    MyArr(2).MyInt = 33
    MyArr(2).MyString = "cool"
    MyArr(2).MyDoubleArr(0) = 111
    MyArr(2).MyDoubleArr(1) = 222
    MyArr(2).MyDoubleArr(2) = 333

    For i = LBound(MyArr) To UBound(MyArr)
        Debug.Print "MyArr: " & MyArr(i).MyString & " " & MyArr(i).MyInt & " " & MyArr(i).MyDoubleArr(0) & " " & MyArr(i).MyDoubleArr(1) & " " & MyArr(i).MyDoubleArr(2)
    Next
End Sub

How to inherit constructors?

public class BaseClass
{
    public BaseClass(params int[] parameters)
    {

    }   
}

public class ChildClass : BaseClass
{
    public ChildClass(params int[] parameters)
        : base(parameters)
    {

    }
}

Scroll to a specific Element Using html

<!-- HTML -->
<a href="#google"></a>
<div id="google"></div>

/*CSS*/
html { scroll-behavior: smooth; } 

Additionally, you can add html { scroll-behavior: smooth; } to your CSS to create a smooth scroll.

How do I see the extensions loaded by PHP?

Are you looking for a particular extension? In your phpinfo();, just hit Ctrl+F in your web browser, type in the first 3-4 letters of the extension you're looking for, and it should show you whether or not its loaded.

Usually in phpinfo() it doesn't show you all the loaded extensions in one location, it has got a separate section for each loaded extension where it shows all of its variables, file paths, etc, so if there is no section for your extension name it probably means it isn't loaded.

Alternatively you can open your php.ini file and use the Ctrl+F method to find your extension, and see if its been commented out (usually by a semicolon near the start of the line).

Is there a css cross-browser value for "width: -moz-fit-content;"?

I use these:

.right {display:table; margin:-18px 0 0 auto;}
.center {display:table; margin:-18px auto 0 auto;}

Update multiple columns in SQL

update T1
set T1.COST2=T1.TOT_COST+2.000,
T1.COST3=T1.TOT_COST+2.000,
T1.COST4=T1.TOT_COST+2.000,
T1.COST5=T1.TOT_COST+2.000,
T1.COST6=T1.TOT_COST+2.000,
T1.COST7=T1.TOT_COST+2.000,
T1.COST8=T1.TOT_COST+2.000,
T1.COST9=T1.TOT_COST+2.000,
T1.COST10=T1.TOT_COST+2.000,
T1.COST11=T1.TOT_COST+2.000,
T1.COST12=T1.TOT_COST+2.000,
T1.COST13=T1.TOT_COST+2.000
from DBRMAST T1 
inner join DBRMAST t2 on t2.CODE=T1.CODE

How to select first child with jQuery?

Use the :first-child selector.

In your example...

$('div.alldivs div:first-child')

This will also match any first child descendents that meet the selection criteria.

While :first matches only a single element, the :first-child selector can match more than one: one for each parent. This is equivalent to :nth-child(1).

For the first matched only, use the :first selector.

Alternatively, Felix Kling suggested using the direct descendent selector to get only direct children...

$('div.alldivs > div:first-child')

How can I strip first and last double quotes?

To remove the first and last characters, and in each case do the removal only if the character in question is a double quote:

import re

s = re.sub(r'^"|"$', '', s)

Note that the RE pattern is different than the one you had given, and the operation is sub ("substitute") with an empty replacement string (strip is a string method but does something pretty different from your requirements, as other answers have indicated).

Preferred way of loading resources in Java

Well, it partly depends what you want to happen if you're actually in a derived class.

For example, suppose SuperClass is in A.jar and SubClass is in B.jar, and you're executing code in an instance method declared in SuperClass but where this refers to an instance of SubClass. If you use this.getClass().getResource() it will look relative to SubClass, in B.jar. I suspect that's usually not what's required.

Personally I'd probably use Foo.class.getResourceAsStream(name) most often - if you already know the name of the resource you're after, and you're sure of where it is relative to Foo, that's the most robust way of doing it IMO.

Of course there are times when that's not what you want, too: judge each case on its merits. It's just the "I know this resource is bundled with this class" is the most common one I've run into.

Error to run Android Studio

Check if your Java JDK is installed correctly

dpkg --list | grep -i jdk

If not, install JDK

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update && sudo apt-get install oracle-java8-installer

After the installation you have to enable the jdk

update-alternatives --display java

Check if Ubuntu uses Java JDK 8

java -version

If all went right the answer should be something like this:

java version "1.8.0_91"
Java(TM) SE Runtime Environment (build 1.8.0_91-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)

Check what compiler is used

javac -version

It should show something like this

javac 1.8.0_91

Finally, add JAVA_HOME to the environment variable

Edit /etc/environment and add JAVA_HOME=/usr/lib/jvm/java-8-oracle to the end of the file

sudo nano /etc/environment

Append to the end of the file

JAVA_HOME=/usr/lib/jvm/java-8-oracle

You will then have to reboot, you can do this from the terminal with:

sudo reboot

In case you want to remove the JDK

sudo apt-get remove oracle-java8-installer

What's the best way to set a single pixel in an HTML5 canvas?

Since different browsers seems to prefer different methods, maybe it would make sense to do a smaller test with all three methods as a part of the loading process to find out which is best to use and then use that throughout the application?

Clear dropdown using jQuery Select2

You should use this one :

   $('#remote').val(null).trigger("change");

Meaning of end='' in the statement print("\t",end='')?

See the documentation for the print function: print()

The content of end is printed after the thing you want to print. By default it contains a newline ("\n") but it can be changed to something else, like an empty string.

Hibernate: How to set NULL query-parameter value with HQL?

This is not a Hibernate specific issue (it's just SQL nature), and YES, there IS a solution for both SQL and HQL:

@Peter Lang had the right idea, and you had the correct HQL query. I guess you just needed a new clean run to pick up the query changes ;-)

The below code absolutely works and it is great if you keep all your queries in orm.xml

from CountryDTO c where ((:status is null and c.status is null) or c.status = :status) and c.type =:type

If your parameter String is null then the query will check if the row's status is null as well. Otherwise it will resort to compare with the equals sign.

Notes:

The issue may be a specific MySql quirk. I only tested with Oracle.

The above query assumes that there are table rows where c.status is null

The where clause is prioritized so that the parameter is checked first.

The parameter name 'type' may be a reserved word in SQL but it shouldn't matter since it is replaced before the query runs.

If you needed to skip the :status where_clause altogether; you can code like so:

from CountryDTO c where (:status is null or c.status = :status) and c.type =:type

and it is equivalent to:

sql.append(" where ");
if(status != null){
  sql.append(" c.status = :status and ");
}
sql.append(" c.type =:type ");

Min width in window resizing

You can set min-width property of CSS for body tag. Since this property is not supported by IE6, you can write like:

body{
   min-width:1000px;        /* Suppose you want minimum width of 1000px */
   width: auto !important;  /* Firefox will set width as auto */
   width:1000px;            /* As IE6 ignores !important it will set width as 1000px; */
}

Or:

body{
   min-width:1000px; // Suppose you want minimum width of 1000px
   _width: expression( document.body.clientWidth > 1000 ? "1000px" : "auto" ); /* sets max-width for IE6 */
}

Align div with fixed position on the right side

You can simply do this:

.test {
  position: -webkit-sticky; /* Safari */
  position: sticky;
  right: 0;
}

Oracle SQL: Use sequence in insert with Select Statement

I tested and the script run ok!

INSERT INTO HISTORICAL_CAR_STATS (HISTORICAL_CAR_STATS_ID, YEAR,MONTH,MAKE,MODEL,REGION,AVG_MSRP,COUNT) 
WITH DATA AS
(
    SELECT '2010' YEAR,'12' MONTH ,'ALL' MAKE,'ALL' MODEL,REGION,sum(AVG_MSRP*COUNT)/sum(COUNT) AVG_MSRP,sum(Count) COUNT
    FROM HISTORICAL_CAR_STATS
    WHERE YEAR = '2010' AND MONTH = '12'
    AND MAKE != 'ALL' GROUP BY REGION
)
SELECT MY_SEQ.NEXTVAL, YEAR,MONTH,MAKE,MODEL,REGION,AVG_MSRP,COUNT
FROM DATA;

you can read this article to understand more! http://www.orafaq.com/wiki/ORA-02287

Where is the visual studio HTML Designer?

Another way of setting the default to the HTML web forms editor is:

  1. At the top menu in Visual Studio go to File > New > File
  2. Select HTML Page
  3. In the lower right corner of the New File dialog on the Open button there is a down arrow
  4. Click it and you should see an option Open With
  5. Select HTML (Web Forms) Editor
  6. Click Set as Default
  7. Press OK

Screenshot showing how to get to the "Open With" dialog box when creating a new file.

In Jenkins, how to checkout a project into a specific directory (using GIT)

It's worth investigating the Pipeline plugin. With the plugin you can checkout multiple VCS projects into relative directory paths. Beforehand creating a directory per VCS checkout. Then issue commands to the newly checked out VCS workspace. In my case I am using git. But you should get the idea.

node{
    def exists = fileExists 'foo'
    if (!exists){
        new File('foo').mkdir()
    }
    dir ('foo') {
        git branch: "<ref spec>", changelog: false, poll: false, url: '<clone url>'
        ......
    }
    def exists = fileExists 'bar'
    if (!exists){
        new File('bar').mkdir()
    }
    dir ('bar') {
        git branch: "<ref spec>", changelog: false, poll: false, url: '<clone url>'
        ......
    }
    def exists = fileExists 'baz'
    if (!exists){
        new File('baz').mkdir()
    }
    dir ('baz') {
        git branch: "<ref spec>", changelog: false, poll: false, url: '<clone url>'
        ......
    }
}

SQL injection that gets around mysql_real_escape_string()

TL;DR

mysql_real_escape_string() will provide no protection whatsoever (and could furthermore munge your data) if:

  • MySQL's NO_BACKSLASH_ESCAPES SQL mode is enabled (which it might be, unless you explicitly select another SQL mode every time you connect); and

  • your SQL string literals are quoted using double-quote " characters.

This was filed as bug #72458 and has been fixed in MySQL v5.7.6 (see the section headed "The Saving Grace", below).

This is another, (perhaps less?) obscure EDGE CASE!!!

In homage to @ircmaxell's excellent answer (really, this is supposed to be flattery and not plagiarism!), I will adopt his format:

The Attack

Starting off with a demonstration...

mysql_query('SET SQL_MODE="NO_BACKSLASH_ESCAPES"'); // could already be set
$var = mysql_real_escape_string('" OR 1=1 -- ');
mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');

This will return all records from the test table. A dissection:

  1. Selecting an SQL Mode

    mysql_query('SET SQL_MODE="NO_BACKSLASH_ESCAPES"');
    

    As documented under String Literals:

    There are several ways to include quote characters within a string:

    • A “'” inside a string quoted with “'” may be written as “''”.

    • A “"” inside a string quoted with “"” may be written as “""”.

    • Precede the quote character by an escape character (“\”).

    • A “'” inside a string quoted with “"” needs no special treatment and need not be doubled or escaped. In the same way, “"” inside a string quoted with “'” needs no special treatment.

    If the server's SQL mode includes NO_BACKSLASH_ESCAPES, then the third of these options—which is the usual approach adopted by mysql_real_escape_string()—is not available: one of the first two options must be used instead. Note that the effect of the fourth bullet is that one must necessarily know the character that will be used to quote the literal in order to avoid munging one's data.

  2. The Payload

    " OR 1=1 -- 
    

    The payload initiates this injection quite literally with the " character. No particular encoding. No special characters. No weird bytes.

  3. mysql_real_escape_string()

    $var = mysql_real_escape_string('" OR 1=1 -- ');
    

    Fortunately, mysql_real_escape_string() does check the SQL mode and adjust its behaviour accordingly. See libmysql.c:

    ulong STDCALL
    mysql_real_escape_string(MYSQL *mysql, char *to,const char *from,
                 ulong length)
    {
      if (mysql->server_status & SERVER_STATUS_NO_BACKSLASH_ESCAPES)
        return escape_quotes_for_mysql(mysql->charset, to, 0, from, length);
      return escape_string_for_mysql(mysql->charset, to, 0, from, length);
    }
    

    Thus a different underlying function, escape_quotes_for_mysql(), is invoked if the NO_BACKSLASH_ESCAPES SQL mode is in use. As mentioned above, such a function needs to know which character will be used to quote the literal in order to repeat it without causing the other quotation character from being repeated literally.

    However, this function arbitrarily assumes that the string will be quoted using the single-quote ' character. See charset.c:

    /*
      Escape apostrophes by doubling them up
    
    // [ deletia 839-845 ]
    
      DESCRIPTION
        This escapes the contents of a string by doubling up any apostrophes that
        it contains. This is used when the NO_BACKSLASH_ESCAPES SQL_MODE is in
        effect on the server.
    
    // [ deletia 852-858 ]
    */
    
    size_t escape_quotes_for_mysql(CHARSET_INFO *charset_info,
                                   char *to, size_t to_length,
                                   const char *from, size_t length)
    {
    // [ deletia 865-892 ]
    
        if (*from == '\'')
        {
          if (to + 2 > to_end)
          {
            overflow= TRUE;
            break;
          }
          *to++= '\'';
          *to++= '\'';
        }
    

    So, it leaves double-quote " characters untouched (and doubles all single-quote ' characters) irrespective of the actual character that is used to quote the literal! In our case $var remains exactly the same as the argument that was provided to mysql_real_escape_string()—it's as though no escaping has taken place at all.

  4. The Query

    mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');
    

    Something of a formality, the rendered query is:

    SELECT * FROM test WHERE name = "" OR 1=1 -- " LIMIT 1
    

As my learned friend put it: congratulations, you just successfully attacked a program using mysql_real_escape_string()...

The Bad

mysql_set_charset() cannot help, as this has nothing to do with character sets; nor can mysqli::real_escape_string(), since that's just a different wrapper around this same function.

The problem, if not already obvious, is that the call to mysql_real_escape_string() cannot know with which character the literal will be quoted, as that's left to the developer to decide at a later time. So, in NO_BACKSLASH_ESCAPES mode, there is literally no way that this function can safely escape every input for use with arbitrary quoting (at least, not without doubling characters that do not require doubling and thus munging your data).

The Ugly

It gets worse. NO_BACKSLASH_ESCAPES may not be all that uncommon in the wild owing to the necessity of its use for compatibility with standard SQL (e.g. see section 5.3 of the SQL-92 specification, namely the <quote symbol> ::= <quote><quote> grammar production and lack of any special meaning given to backslash). Furthermore, its use was explicitly recommended as a workaround to the (long since fixed) bug that ircmaxell's post describes. Who knows, some DBAs might even configure it to be on by default as means of discouraging use of incorrect escaping methods like addslashes().

Also, the SQL mode of a new connection is set by the server according to its configuration (which a SUPER user can change at any time); thus, to be certain of the server's behaviour, you must always explicitly specify your desired mode after connecting.

The Saving Grace

So long as you always explicitly set the SQL mode not to include NO_BACKSLASH_ESCAPES, or quote MySQL string literals using the single-quote character, this bug cannot rear its ugly head: respectively escape_quotes_for_mysql() will not be used, or its assumption about which quote characters require repeating will be correct.

For this reason, I recommend that anyone using NO_BACKSLASH_ESCAPES also enables ANSI_QUOTES mode, as it will force habitual use of single-quoted string literals. Note that this does not prevent SQL injection in the event that double-quoted literals happen to be used—it merely reduces the likelihood of that happening (because normal, non-malicious queries would fail).

In PDO, both its equivalent function PDO::quote() and its prepared statement emulator call upon mysql_handle_quoter()—which does exactly this: it ensures that the escaped literal is quoted in single-quotes, so you can be certain that PDO is always immune from this bug.

As of MySQL v5.7.6, this bug has been fixed. See change log:

Functionality Added or Changed

Safe Examples

Taken together with the bug explained by ircmaxell, the following examples are entirely safe (assuming that one is either using MySQL later than 4.1.20, 5.0.22, 5.1.11; or that one is not using a GBK/Big5 connection encoding):

mysql_set_charset($charset);
mysql_query("SET SQL_MODE=''");
$var = mysql_real_escape_string('" OR 1=1 /*');
mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');

...because we've explicitly selected an SQL mode that doesn't include NO_BACKSLASH_ESCAPES.

mysql_set_charset($charset);
$var = mysql_real_escape_string("' OR 1=1 /*");
mysql_query("SELECT * FROM test WHERE name = '$var' LIMIT 1");

...because we're quoting our string literal with single-quotes.

$stmt = $pdo->prepare('SELECT * FROM test WHERE name = ? LIMIT 1');
$stmt->execute(["' OR 1=1 /*"]);

...because PDO prepared statements are immune from this vulnerability (and ircmaxell's too, provided either that you're using PHP=5.3.6 and the character set has been correctly set in the DSN; or that prepared statement emulation has been disabled).

$var  = $pdo->quote("' OR 1=1 /*");
$stmt = $pdo->query("SELECT * FROM test WHERE name = $var LIMIT 1");

...because PDO's quote() function not only escapes the literal, but also quotes it (in single-quote ' characters); note that to avoid ircmaxell's bug in this case, you must be using PHP=5.3.6 and have correctly set the character set in the DSN.

$stmt = $mysqli->prepare('SELECT * FROM test WHERE name = ? LIMIT 1');
$param = "' OR 1=1 /*";
$stmt->bind_param('s', $param);
$stmt->execute();

...because MySQLi prepared statements are safe.

Wrapping Up

Thus, if you:

  • use native prepared statements

OR

  • use MySQL v5.7.6 or later

OR

  • in addition to employing one of the solutions in ircmaxell's summary, use at least one of:

    • PDO;
    • single-quoted string literals; or
    • an explicitly set SQL mode that does not include NO_BACKSLASH_ESCAPES

...then you should be completely safe (vulnerabilities outside the scope of string escaping aside).

Is there any advantage of using map over unordered_map in case of trivial keys?

Significant differences that have not really been adequately mentioned here:

  • map keeps iterators to all elements stable, in C++17 you can even move elements from one map to the other without invalidating iterators to them (and if properly implemented without any potential allocation).
  • map timings for single operations are typically more consistent since they never need large allocations.
  • unordered_map using std::hash as implemented in the libstdc++ is vulnerable to DoS if fed with untrusted input (it uses MurmurHash2 with a constant seed - not that seeding would really help, see https://emboss.github.io/blog/2012/12/14/breaking-murmur-hash-flooding-dos-reloaded/).
  • Being ordered enables efficient range searches, e.g. iterate over all elements with key = 42.

Convert Word doc, docx and Excel xls, xlsx to PDF with PHP

Step 1. Install "Apache_OpenOffice_4.1.2" in your system Step 2. Download "unoconv" library from github or any where else.

-> C:\Program Files (x86)\OpenOffice 4\program\python.exe = Path of open office install directory

-> D:\wamp\www\doc_to_pdf\libobasis4.4-pyuno\unoconv = Path of library folder

-> D:/wamp/www/doc_to_pdf/files/'.$pdf_File_name.' = path and file name of pdf

-> D:/wamp/www/doc_to_pdf/files/'.$doc_file_name = Path of your document file.

If pdf not created than last step is Go to ->Control Panel\All Control Panel Items\Administrative Tools-> services-> find "wampapache" -> right click and click on property -> click on logon tab Than check checkbox of allow service to interact with desktop

Create sample .php file and put below code and run on wamp or xampp server

$result = exec('"C:\Program Files (x86)\OpenOffice 4\program\python.exe" D:\wamp\www\doc_to_pdf\libobasis4.4-pyuno\unoconv -f pdf -o D:/wamp/www/doc_to_pdf/files/'.$pdf_File_name.' D:/wamp/www/doc_to_pdf/files/'.$doc_file_name);

This code working for me in windows-8 operating system

Function names in C++: Capitalize or not?

It all depends on your definition of correct. There are many ways in which you can evaluate your coding style. Readability is an important one (for me). That is why I would use the my_function way of writing function names and variable names.

Class not registered Error

My problem and the solution

  1. I have a 32 bit third party dll which I have installed in 2008 R2 machine which is 64 bit.

  2. I have a wcf service created in .net 4.5 framework which calls the 32 bit third party dll for process. Now I have build property set to target 'any' cpu and deployed it to the 64 bit machine.

  3. When Ii tried to invoke the wcf service got error "80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG"

  4. Now Ii used ProcMon.exe to trace the com registry issue and identified that the process is looking for the registry entry at HKLM\CLSID and HKCR\CLSID where there is no entry.

  5. Came to know that Microsoft will not register the 32 bit com components to the paths HKLM\CLSID, HKCR\CLSID in 64 bit machine rather it places the entry in HKLM\Wow6432Node\CLSID and HKCR\Wow6432Node\CLSID paths.

  6. Now the conflict is 64 bit process trying to invoke 32 bit process in 64 bit machine which will look for the registry entry in HKLM\CLSID, HKCR\CLSID. The solution is we have to force the 64 bit process to look at the registry entry at HKLM\Wow6432Node\CLSID and HKCR\Wow6432Node\CLSID.

  7. This can be achieved by configuring the wcf service project properties to target to 'X86' machine instead of 'Any'.

  8. After deploying the 'X86' version to the 2008 R2 server got the issue "System.BadImageFormatException: Could not load file or assembly"

  9. Solution to this badimageformatexception is setting the 'Enable32bitApplications' to 'True' in IIS Apppool properties for the right apppool.

GitHub: invalid username or password

If like me you just updated your password and ran git push to run into this issue, then there's a super easy fix.

For Mac users only. You need to delete your OSX Keychain access entries for GitHub. You can do it via terminal by running the following commands.

Deleting your credentials via the command line

Through the command line, you can use the credential helper directly to erase the keychain entry.

To do this, type the following command:

git credential-osxkeychain erase
host=github.com
protocol=https

# [Now Press Return]

If it's successful, nothing will print out. To test that it works, try and clone a repository from GitHub or run your previous action again like in my case git push. If you are prompted for a password, the keychain entry was deleted.

Java String remove all non numeric characters

For the Android folks coming here for Kotlin

val dirtyString = " Account Balance: $-12,345.67"
val cleanString = dirtyString.replace("[^\\d.]".toRegex(), "")

Output:

cleanString = "12345.67"

This could then be safely converted toDouble(), toFloat() or toInt() if needed

Composer - the requested PHP extension mbstring is missing from your system

I set the PHPRC variable and uncommented zend_extension=php_opcache.dll in php.ini and all works well.

A Simple AJAX with JSP example

You are doing mistake in "configuration_page.jsp" file. here in this file , function loadXMLDoc() 's line number 2 should be like this:

var config=document.getElementsByName('configselect').value;

because you have declared only the name attribute in your <select> tag. So you should get this element by name.

After correcting this, it will run without any JavaScript error

How can I put strings in an array, split by new line?

For anyone trying to display cronjobs in a crontab and getting frustrated on how to separate each line, use explode:

$output = shell_exec('crontab -l');
$cron_array = explode(chr(10),$output);

using '\n' doesnt seem to work but chr(10) works nicely :D

hope this saves some one some headaches.

Android: Tabs at the BOTTOM

Yes, see: link, but he used xml layouts, not activities to create new tab, so put his xml code (set paddingTop for FrameLayout - 0px) and then write the code:

public class SomeActivity extends ActivityGroup {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  setContentView(R.layout.main);

    TabHost tab_host = (TabHost) findViewById(R.id.edit_item_tab_host); 

    tab_host.setup(this.getLocalActivityManager());

    TabSpec ts1 = tab_host.newTabSpec("TAB_DATE"); 
    ts1.setIndicator("tab1"); 
    ts1.setContent(new Intent(this, Registration.class)); 
    tab_host.addTab(ts1); 

    TabSpec ts2 = tab_host.newTabSpec("TAB_GEO"); 
    ts2.setIndicator("tab2"); 
    ts2.setContent(new Intent(this, Login.class)); 
    tab_host.addTab(ts2); 

    TabSpec ts3 = tab_host.newTabSpec("TAB_TEXT"); 
    ts3.setIndicator("tab3"); 
    ts3.setContent(new Intent(this, Registration.class)); 
    tab_host.addTab(ts3); 

    tab_host.setCurrentTab(0);      


}

}

curl error 18 - transfer closed with outstanding read data remaining

I had this problem working with pycurl and I solved it using

c.setopt(pycurl.HTTP_VERSION, pycurl.CURL_HTTP_VERSION_1_0) 

like Eric Caron says.

.htaccess or .htpasswd equivalent on IIS?

I've never used it but Trilead, a free ISAPI filter which enables .htaccess based control, looks like what you want.

Some dates recognized as dates, some dates not recognized. Why?

In your case it is probably taking them in DD-MM-YY format, not MM-DD-YY.

Escaping single quotes in JavaScript string for JavaScript evaluation

That worked for me.

string address=senderAddress.Replace("'", "\\'");

Convert seconds to HH-MM-SS with JavaScript?

below is the given code which will convert seconds into hh-mm-ss format:

var measuredTime = new Date(null);
measuredTime.setSeconds(4995); // specify value of SECONDS
var MHSTime = measuredTime.toISOString().substr(11, 8);

Get alternative method from Convert seconds to HH-MM-SS format in JavaScript

Create a file if one doesn't exist - C

If fptr is NULL, then you don't have an open file. Therefore, you can't freopen it, you should just fopen it.

FILE *fptr;
fptr = fopen("scores.dat", "rb+");
if(fptr == NULL) //if file does not exist, create it
{
    fptr = fopen("scores.dat", "wb");
}

note: Since the behavior of your program varies depending on whether the file is opened in read or write modes, you most probably also need to keep a variable indicating which is the case.

A complete example

int main()
{
    FILE *fptr;
    char there_was_error = 0;
    char opened_in_read  = 1;
    fptr = fopen("scores.dat", "rb+");
    if(fptr == NULL) //if file does not exist, create it
    {
        opened_in_read = 0;
        fptr = fopen("scores.dat", "wb");
        if (fptr == NULL)
            there_was_error = 1;
    }
    if (there_was_error)
    {
        printf("Disc full or no permission\n");
        return EXIT_FAILURE;
    }
    if (opened_in_read)
        printf("The file is opened in read mode."
               " Let's read some cached data\n");
    else
        printf("The file is opened in write mode."
               " Let's do some processing and cache the results\n");
    return EXIT_SUCCESS;
}

Removing u in list

[u'{email:[email protected],gem:0}', u'{email:test,gem:0}', u'{email:test,gem:0}', u'{email:test,gem:0}', u'{email:test,gem:0}', u'{email:test1,gem:0}']

'u' denotes unicode characters. We can easily remove this with map function on the final list element

map(str, test)

Another way is when you are appending it to the list

test.append(str(a))

Using malloc for allocation of multi-dimensional arrays with different row lengths

2-D Array Dynamic Memory Allocation

int **a,i;

// for any number of rows & columns this will work
a = (int **)malloc(rows*sizeof(int *));
for(i=0;i<rows;i++)
    *(a+i) = (int *)malloc(cols*sizeof(int));

Vertically centering Bootstrap modal window

To add vertical modal centering to bootstrap modal.js I added this at the end of the Modal.prototype.show function:

var $modalDialog = $('.modal-dialog'),
        modalHeight = $modalDialog.height(),
        browserHeight = window.innerHeight;

    $modalDialog.css({'margin-top' : modalHeight >= browserHeight ? 0 : (browserHeight - modalHeight)/2});

passing several arguments to FUN of lapply (and others *apply)

You can do it in the following way:

 myfxn <- function(var1,var2,var3){
      var1*var2*var3

    }

    lapply(1:3,myfxn,var2=2,var3=100)

and you will get the answer:

[[1]] [1] 200

[[2]] [1] 400

[[3]] [1] 600

A url resource that is a dot (%2E)

It is not possible. §2.3 says that "." is an unreserved character and that "URIs that differ in the replacement of an unreserved character with its corresponding percent-encoded US-ASCII octet are equivalent". Therefore, /%2E%2E/ is the same as /../, and that will get normalized away.

(This is a combination of an answer by bobince and a comment by slowpoison.)

Which command do I use to generate the build of a Vue app?

If you run into problems with your path, maybe you need to change the assetPublicPath in your config/index.js file to your sub-directory:

http://vuejs-templates.github.io/webpack/backend.html

How to clear the JTextField by clicking JButton

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        textfield.setText("");
        //textfield.setText(null); //or use this
    }
});

Also See
How to Use Buttons

Insert default value when parameter is null

Try an if statement ...

if @value is null 
    insert into t (value) values (default)
else
    insert into t (value) values (@value)

Creating an empty list in Python

list() is inherently slower than [], because

  1. there is symbol lookup (no way for python to know in advance if you did not just redefine list to be something else!),

  2. there is function invocation,

  3. then it has to check if there was iterable argument passed (so it can create list with elements from it) ps. none in our case but there is "if" check

In most cases the speed difference won't make any practical difference though.

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

Personally, I prefer changing the method signature to:

public ResponseEntity<?>

This gives the advantage of possibly returning an error message as single item for services which, when ok, return a list of items.

When returning I don't use any type (which is unused in this case anyway):

return new ResponseEntity<>(entities, HttpStatus.OK);

Going to a specific line number using Less in Unix

For editing this is possible in nano via +n from command line, e.g.,

nano +16 file.txt

To open file.txt to line 16.

Standardize data columns in R

Realizing that the question is old and one answer is accepted, I'll provide another answer for reference.

scale is limited by the fact that it scales all variables. The solution below allows to scale only specific variable names while preserving other variables unchanged (and the variable names could be dynamically generated):

library(dplyr)

set.seed(1234)
dat <- data.frame(x = rnorm(10, 30, .2), 
                  y = runif(10, 3, 5),
                  z = runif(10, 10, 20))
dat

dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
dat2

which gives me this:

> dat
          x        y        z
1  29.75859 3.633225 14.56091
2  30.05549 3.605387 12.65187
3  30.21689 3.318092 13.04672
4  29.53086 3.079992 15.07307
5  30.08582 3.437599 11.81096
6  30.10121 4.621197 17.59671
7  29.88505 4.051395 12.01248
8  29.89067 4.829316 12.58810
9  29.88711 4.662690 19.92150
10 29.82199 3.091541 18.07352

and

> dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
> dat2
          x          y           z
1  29.75859 -0.3004815 -0.06016029
2  30.05549 -0.3423437 -0.72529604
3  30.21689 -0.7743696 -0.58772361
4  29.53086 -1.1324181  0.11828039
5  30.08582 -0.5946582 -1.01827752
6  30.10121  1.1852038  0.99754666
7  29.88505  0.3283513 -0.94806607
8  29.89067  1.4981677 -0.74751378
9  29.88711  1.2475998  1.80753470
10 29.82199 -1.1150515  1.16367556

EDIT 1 (2016): Addressed Julian's comment: the output of scale is Nx1 matrix so ideally we should add an as.vector to convert the matrix type back into a vector type. Thanks Julian!

EDIT 2 (2019): Quoting Duccio A.'s comment: For the latest dplyr (version 0.8) you need to change dplyr::funcs with list, like dat %>% mutate_each_(list(~scale(.) %>% as.vector), vars=c("y","z"))

EDIT 3 (2020): Thanks to @mj_whales: the old solution is deprecated and now we need to use mutate_at.

What does 'corrupted double-linked list' mean

This might be caused due to different reasons, some user have mentioned other possibilities and I add my case:

I got this error when using multi-threading (both std::pthread and std::thread) and the error occurred because I forgot to lock a variable which multi threads may change at the same time. this error comes randomly in some runs but not all because ... you know accident between to threads is random.

That variable in my case was a global std::vector which I tried to push_back() something into it in a function called by threads.. and then I used a std::mutex and never got this error again.

may help some

Change the color of a bullet in a html list?

I managed this without adding markup, but instead using li:before. This obviously has all the limitations of :before (no old IE support), but it seems to work with IE8, Firefox and Chrome after some very limited testing. It's working in our controller environment, wondering if anyone could check this. The bullet style is also limited by what's in unicode.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <style type="text/css">
    li {
      list-style: none;
    }

    li:before {
      /* For a round bullet */
      content:'\2022';
      /* For a square bullet */
      /*content:'\25A0';*/
      display: block;
      position: relative;
      max-width: 0px;
      max-height: 0px;
      left: -10px;
      top: -0px;
      color: green;
      font-size: 20px;
    }
  </style>
</head>

<body>
  <ul>
    <li>foo</li>
    <li>bar</li>
  </ul>
</body>
</html>

How do I make a "div" button submit the form its sitting in?

To keep the scripting in one place rather than using onClick in the HTML tag, add the following code to your script block:

$('#id-of-the-button').click(function() {document.forms[0].submit()});

Which assumes you just have the one form on the page.

How do I call a function twice or more times consecutively?

from itertools import repeat, starmap

results = list(starmap(do, repeat((), 3)))

See the repeatfunc recipe from the itertools module that is actually much more powerful. If you need to just call the method but don't care about the return values you can use it in a for loop:

for _ in starmap(do, repeat((), 3)): pass

but that's getting ugly.

Errno 10061 : No connection could be made because the target machine actively refused it ( client - server )

Using the examples from: https://docs.python.org/3.2/library/socketserver.html I determined that I needed to set the HOST port to the machine I had the server program running on. So TCPServer on 192.168.0.1 HOST = TCPServer IP 192.168.0.1 then I had to set the TCPClient side to point to the TCPServer IP. So the TCPClient HOST value = 192.168.0.1 - Sorry, that's the best I can describe it.

How do I include image files in Django templates?

/media directory under project root

Settings.py

BASE_DIR = os.path.dirname(os.path.dirname(__file__))
MEDIA_URL = '/media/'
MEDIA_ROOT = os.path.join(BASE_DIR, 'media')

urls.py

    urlpatterns += patterns('django.views.static',(r'^media/(?P<path>.*)','serve',{'document_root':settings.MEDIA_ROOT}), )

template

<img src="{{MEDIA_URL}}/image.png" > 

What causes imported Maven project in Eclipse to use Java 1.5 instead of Java 1.6 by default and how can I ensure it doesn't?

One more possible reason if you are using Tycho and Maven to build bundles, that you have wrong execution environment (Bundle-RequiredExecutionEnvironment) in the manifest file (manifest.mf) defined. For example:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Engine Plug-in
Bundle-SymbolicName: com.foo.bar
Bundle-Version: 4.6.5.qualifier
Bundle-Activator: com.foo.bar.Activator
Bundle-Vendor: Foobar Technologies Ltd.
Require-Bundle: org.eclipse.core.runtime,
 org.jdom;bundle-version="1.0.0",
 org.apache.commons.codec;bundle-version="1.3.0",
 bcprov-ext;bundle-version="1.47.0"
Bundle-RequiredExecutionEnvironment: JavaSE-1.5
Export-Package: ...
...
Import-Package: ...
...

In my case everything else was ok. The compiler plugins (normal maven and tycho as well) were set correctly, still m2 generated old compliance level because of the manifest. I thought I share the experience.

Access images inside public folder in laravel

In my case it worked perfectly

<img style="border-radius: 50%;height: 50px;width: 80px;"  src="<?php echo asset("storage/TeacherImages/{$teacher->profilePic}")?>">

this is used to display image from folder i hope this will help someone looking for this type of code

How to clear an EditText on click?

Be careful when setting text with an onClick listener on the field you are setting the text. I was doing this and setting the text to an empty string. This was causing the pointer to come up to indicate where my cursor was, which will normally go away after a few seconds. When I did not wait for it to go away before leaving my page causing finish() to be called, it would cause a memory leak and crash my app. Took me a while to figure out what was causing the crash on this one..

Anyway, I would recommend using selectAll() in your on click listener rather than setText() if you can. This way, once the text is selected, the user can start typing and all of the previous text will be cleared.

pic of the suspect pointer: http://i.stack.imgur.com/juJnt.png

How do I convert the date from one format to another date object in another format without using any deprecated classes?

tl;dr

LocalDate.parse( 
    "January 08, 2017" , 
    DateTimeFormatter.ofPattern( "MMMM dd, uuuu" , Locale.US ) 
).format( DateTimeFormatter.BASIC_ISO_DATE ) 

Using java.time

The Question and other Answers use troublesome old date-time classes, now legacy, supplanted by the java.time classes.

You have date-only values, so use a date-only class. The LocalDate class represents a date-only value without time-of-day and without time zone.

String input = "January 08, 2017";
Locale l = Locale.US ;
DateTimeFormatter f = DateTimeFormatter.ofPattern( "MMMM dd, uuuu" , l );
LocalDate ld = LocalDate.parse( input , f );

Your desired output format is defined by the ISO 8601 standard. For a date-only value, the “expanded” format is YYYY-MM-DD such as 2017-01-08 and the “basic” format that minimizes the use of delimiters is YYYYMMDD such as 20170108.

I strongly suggest using the expanded format for readability. But if you insist on the basic format, that formatter is predefined as a constant on the DateTimeFormatter class named BASIC_ISO_DATE.

String output = ld.format( DateTimeFormatter.BASIC_ISO_DATE );

See this code run live at IdeOne.com.

ld.toString(): 2017-01-08

output: 20170108


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Can I edit an iPad's host file?

No, you can't change iPad's host file(without jailbreak), but can workaround.

Here is my scenario:

  • Mac OS X, with IP 192.168.2.1, running a web app
  • iPad, the device you would like to test the web app
  • Charles (for Mac), enables HTTP proxy for your iPad

I am going to test the web app running in my Mac via iPad, but I can't access directly to it.

The solution works for me:

  • Firstly, make sure that your server and iPad are in the same local network.
  • Then, set up Charles proxy, in the menu "Proxy > Proxy Settings...", fill in Port(mostly 8888) and toggle Enable transparent HTTP proxying.

enter image description here


  • Setup proxy setting in iPad.

enter image description here

Now you can visit your web app in iPad.

Of course you can use other proxy tools like Squid or Varnish in Linux, or fiddler in Wondows.

Remove the last three characters from a string

I read through all these, but wanted something a bit more elegant. Just to remove a certain number of characters from the end of a string:

string.Concat("hello".Reverse().Skip(3).Reverse());

output:

"he"

Java 8 lambdas, Function.identity() or t->t

In your example there is no big difference between str -> str and Function.identity() since internally it is simply t->t.

But sometimes we can't use Function.identity because we can't use a Function. Take a look here:

List<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);

this will compile fine

int[] arrayOK = list.stream().mapToInt(i -> i).toArray();

but if you try to compile

int[] arrayProblem = list.stream().mapToInt(Function.identity()).toArray();

you will get compilation error since mapToInt expects ToIntFunction, which is not related to Function. Also ToIntFunction doesn't have identity() method.

Bootstrap Align Image with text

i am a new bee ;p . And i faced the same problem. And the solution is BS Media objects. please see the code..

<div class="media">
   <div class="media-left media-top">
    <img src="something.png" alt="@l!" class="media-object" width="20" height="50"/>
    </div>
   <div class="media-body">
      <h2 class="media-heading">Beside Image</h2>
   </div>
</div>

error: pathspec 'test-branch' did not match any file(s) known to git

You can also get this error with any version of git if the remote branch was created after your last clone/fetch and your local repo doesn't know about it yet. I solved it by doing a git fetch first which "tells" your local repo about all the remote branches.

git fetch
git checkout test-branch

copy all files and folders from one drive to another drive using DOS (command prompt)

try this command, xcopy c:\ (file or directory path) F:\ /e. If you want more details refer this site [[http://www.computerhope.com/xcopyhlp.htm]]

Assigning a variable NaN in python without numpy

Use float("nan"):

>>> float("nan")
nan

Operation is not valid due to the current state of the object, when I select a dropdown list

From http://codecorner.galanter.net/2012/06/04/solution-for-operation-is-not-valid-due-to-the-current-state-of-the-object-error/

Issue happens because Microsoft Security Update MS11-100 limits number of keys in Forms collection during HTTP POST request. To alleviate this problem you need to increase that number.

This can be done in your application Web.Config in the <appSettings> section (create the section directly under <configuration> if it doesn’t exist). Add 2 lines similar to the lines below to the section:

<add key="aspnet:MaxHttpCollectionKeys" value="2000" />
<add key="aspnet:MaxJsonDeserializerMembers" value="2000" />

The above example set the limit to 2000 keys. This will lift the limitation and the error should go away.

jQuery select all except first

_x000D_
_x000D_
$(document).ready(function(){_x000D_
_x000D_
  $(".btn1").click(function(){_x000D_
          $("div.test:not(:first)").hide();_x000D_
  });_x000D_
_x000D_
  $(".btn2").click(function(){_x000D_
           $("div.test").show();_x000D_
          $("div.test:not(:first):not(:last)").hide();_x000D_
  });_x000D_
_x000D_
  $(".btn3").click(function(){_x000D_
          $("div.test").hide();_x000D_
          $("div.test:not(:first):not(:last)").show();_x000D_
  });_x000D_
_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<button class="btn1">Hide All except First</button>_x000D_
<button class="btn2">Hide All except First & Last</button>_x000D_
<button class="btn3">Hide First & Last</button>_x000D_
_x000D_
<br/>_x000D_
_x000D_
<div class='test'>First</div>_x000D_
<div class='test'>Second</div>_x000D_
<div class='test'>Third</div>_x000D_
<div class='test'>Last</div>
_x000D_
_x000D_
_x000D_

Why does ++[[]][+[]]+[+[]] return the string "10"?

Step by steps of that, + turn value to a number and if you add to an empty array +[]...as it's empty and is equal to 0, it will

So from there, now look into your code, it's ++[[]][+[]]+[+[]]...

And there is plus between them ++[[]][+[]] + [+[]]

So these [+[]] will return [0] as they have an empty array which gets converted to 0 inside the other array...

So as imagine, the first value is a 2-dimensional array with one array inside... so [[]][+[]] will be equal to [[]][0] which will return []...

And at the end ++ convert it and increase it to 1...

So you can imagine, 1 + "0" will be "10"...

Why does return the string “10”?

Can't import Numpy in Python

The following command worked for me:

python.exe -m pip install numpy

php timeout - set_time_limit(0); - don't work

Checkout this, This is from PHP MANUAL, This may help you.

If you're using PHP_CLI SAPI and getting error "Maximum execution time of N seconds exceeded" where N is an integer value, try to call set_time_limit(0) every M seconds or every iteration. For example:

<?php

require_once('db.php');

$stmt = $db->query($sql);

while ($row = $stmt->fetchRow()) {
    set_time_limit(0);
    // your code here
}

?>

I can't access http://localhost/phpmyadmin/

Or it could be that Skype is running on the same port (it does by default).

Disable Skype or configure Skype to use another port

AlertDialog styling - how to change style (color) of title, message, etc

You need to define a Theme for your AlertDialog and reference it in your Activity's theme. The attribute is alertDialogTheme and not alertDialogStyle. Like this:

<style name="Theme.YourTheme" parent="@android:style/Theme.Holo">
    ...
    <item name="android:alertDialogTheme">@style/YourAlertDialogTheme</item>
</style>

<style name="YourAlertDialogTheme">
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
    <item name="android:windowMinWidthMajor">@android:dimen/dialog_min_width_major</item>
    <item name="android:windowMinWidthMinor">@android:dimen/dialog_min_width_minor</item>
    <item name="android:windowTitleStyle">...</item>
    <item name="android:textAppearanceMedium">...</item>
    <item name="android:borderlessButtonStyle">...</item>
    <item name="android:buttonBarStyle">...</item>
</style>

You'll be able to change color and text appearance for the title, the message and you'll have some control on the background of each area. I wrote a blog post detailing the steps to style an AlertDialog.

Displaying better error message than "No JSON object could be decoded"

For my particular version of this problem, I went ahead and searched the function declaration of load_json_file(path) within the packaging.py file, then smuggled a print line into it:

def load_json_file(path):
    data = open(path, 'r').read()
    print data
    try:
        return Bunch(json.loads(data))
    except ValueError, e:
        raise MalformedJsonFileError('%s when reading "%s"' % (str(e),
                                                               path))

That way it would print the content of the json file before entering the try-catch, and that way – even with my barely existing Python knowledge – I was able to quickly figure out why my configuration couldn't read the json file.
(It was because I had set up my text editor to write a UTF-8 BOM … stupid)

Just mentioning this because, while maybe not a good answer to the OP's specific problem, this was a rather quick method in determining the source of a very oppressing bug. And I bet that many people will stumble upon this article who are searching a more verbose solution for a MalformedJsonFileError: No JSON object could be decoded when reading …. So that might help them.

How to extract string following a pattern with grep, regex or perl

The regular expression would be:

.+name="([^"]+)"

Then the grouping would be in the \1

Appending to an object

How about storing the alerts as records in an array instead of properties of a single object ?

var alerts = [ 
    {num : 1, app:'helloworld',message:'message'},
    {num : 2, app:'helloagain',message:'another message'} 
]

And then to add one, just use push:

alerts.push({num : 3, app:'helloagain_again',message:'yet another message'});

How to check for a Null value in VB.NET

If you are using a strongly-typed dataset then you should do this:

If Not ediTransactionRow.Ispay_id1Null Then
    'Do processing here
End If

You are getting the error because a strongly-typed data set retrieves the underlying value and exposes the conversion through the property. For instance, here is essentially what is happening:

Public Property pay_Id1 Then
   Get
     return DirectCast(me.GetValue("pay_Id1", short)
   End Get
   'Abbreviated for clarity
End Property

The GetValue method is returning DBNull which cannot be converted to a short.

Convert SVG to PNG in Python

I did not find any of the answers satisfactory. All the mentioned libraries have some problem or the other like Cairo dropping support for python 3.6 (they dropped Python 2 support some 3 years ago!). Also, installing the mentioned libraries on the Mac was a pain.

Finally, I found the best solution was svglib + reportlab. Both installed without a hitch using pip and first call to convert from svg to png worked beautifully! Very happy with the solution.

Just 2 commands do the trick:

from svglib.svglib import svg2rlg
from reportlab.graphics import renderPM
drawing = svg2rlg("my.svg")
renderPM.drawToFile(drawing, "my.png", fmt="PNG")

Are there any limitations with these I should be aware of?

Couldn't process file resx due to its being in the Internet or Restricted zone or having the mark of the web on the file

None of the above worked.

  • The "Unblock" option is not present in the explorer properties.
  • Recreating file, adding folder (and resx file) to Tools->Options->Trust Settings does not work.

The solution was to copy the project locally (from the network drive).

A reference to the dll could not be added

I have the same problem with importing WinSCard.dll in my project. I deal with that importing directly from dll like this:

[DllImport("winscard.dll")]
public static extern int SCardEstablishContext(int dwScope, int pvReserved1, int pvReserved2, ref int phContext);

[DllImport("winscard.dll")]
public static extern int SCardReleaseContext(int phContext);

You could add this to separate project and then add a reference from your main project.

Performing SQL queries on an Excel Table within a Workbook with VBA Macro

Building on Joan-Diego Rodriguez's routine with Jordi's approach and some of Jacek Kotowski's code - This function converts any table name for the active workbook into a usable address for SQL queries.

Note to MikeL: Addition of "[#All]" includes headings avoiding problems you reported.

Function getAddress(byVal sTableName as String) as String 

    With Range(sTableName & "[#All]")
        getAddress= "[" & .Parent.Name & "$" & .Address(False, False) & "]"
    End With

End Function

How can I create an Asynchronous function in Javascript?

MDN has a good example on the use of setTimeout preserving "this".

Like the following:

function doSomething() {
    // use 'this' to handle the selected element here
}

$(".someSelector").each(function() {
    setTimeout(doSomething.bind(this), 0);
});

writing a batch file that opens a chrome URL

@ECHO OFF
"c:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --app="https://tweetdeck.twitter.com/"

@ECHO OFF
"c:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --app="https://web.whatsapp.com/"

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

The following steps are to reset the password for a user in case you forgot, this would also solve your mentioned error.

First, stop your MySQL:

sudo /etc/init.d/mysql stop

Now start up MySQL in safe mode and skip the privileges table:

sudo mysqld_safe --skip-grant-tables &

Login with root:

mysql -uroot

And assign the DB that needs to be used:

use mysql;

Now all you have to do is reset your root password of the MySQL user and restart the MySQL service:

update user set password=PASSWORD("YOURPASSWORDHERE") where User='root';

flush privileges;

quit and restart MySQL:

quit

sudo /etc/init.d/mysql stop sudo /etc/init.d/mysql start Now your root password should be working with the one you just set, check it with:

mysql -u root -p

How to create a date and time picker in Android?

Use this function it will enable you to pic date and time one by one then set it to global variable date. No library no XML.

Calendar date;
public void showDateTimePicker() {
   final Calendar currentDate = Calendar.getInstance();
   date = Calendar.getInstance();
   new DatePickerDialog(context, new DatePickerDialog.OnDateSetListener() {
       @Override
       public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
            date.set(year, monthOfYear, dayOfMonth);
            new TimePickerDialog(context, new TimePickerDialog.OnTimeSetListener() {
                @Override
                public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                    date.set(Calendar.HOUR_OF_DAY, hourOfDay);
                    date.set(Calendar.MINUTE, minute);
                    Log.v(TAG, "The choosen one " + date.getTime());
                }
            }, currentDate.get(Calendar.HOUR_OF_DAY), currentDate.get(Calendar.MINUTE), false).show();
       }
   }, currentDate.get(Calendar.YEAR), currentDate.get(Calendar.MONTH), currentDate.get(Calendar.DATE)).show();
}

How can I pad an int with leading zeros when using cout << operator?

cout.fill('*');
cout << -12345 << endl; // print default value with no field width
cout << setw(10) << -12345 << endl; // print default with field width
cout << setw(10) << left << -12345 << endl; // print left justified
cout << setw(10) << right << -12345 << endl; // print right justified
cout << setw(10) << internal << -12345 << endl; // print internally justified

This produces the output:

-12345
****-12345
-12345****
****-12345
-****12345

How do I tokenize a string in C++?

Seems odd to me that with all us speed conscious nerds here on SO no one has presented a version that uses a compile time generated look up table for the delimiter (example implementation further down). Using a look up table and iterators should beat std::regex in efficiency, if you don't need to beat regex, just use it, its standard as of C++11 and super flexible.

Some have suggested regex already but for the noobs here is a packaged example that should do exactly what the OP expects:

std::vector<std::string> split(std::string::const_iterator it, std::string::const_iterator end, std::regex e = std::regex{"\\w+"}){
    std::smatch m{};
    std::vector<std::string> ret{};
    while (std::regex_search (it,end,m,e)) {
        ret.emplace_back(m.str());              
        std::advance(it, m.position() + m.length()); //next start position = match position + match length
    }
    return ret;
}
std::vector<std::string> split(const std::string &s, std::regex e = std::regex{"\\w+"}){  //comfort version calls flexible version
    return split(s.cbegin(), s.cend(), std::move(e));
}
int main ()
{
    std::string str {"Some people, excluding those present, have been compile time constants - since puberty."};
    auto v = split(str);
    for(const auto&s:v){
        std::cout << s << std::endl;
    }
    std::cout << "crazy version:" << std::endl;
    v = split(str, std::regex{"[^e]+"});  //using e as delim shows flexibility
    for(const auto&s:v){
        std::cout << s << std::endl;
    }
    return 0;
}

If we need to be faster and accept the constraint that all chars must be 8 bits we can make a look up table at compile time using metaprogramming:

template<bool...> struct BoolSequence{};        //just here to hold bools
template<char...> struct CharSequence{};        //just here to hold chars
template<typename T, char C> struct Contains;   //generic
template<char First, char... Cs, char Match>    //not first specialization
struct Contains<CharSequence<First, Cs...>,Match> :
    Contains<CharSequence<Cs...>, Match>{};     //strip first and increase index
template<char First, char... Cs>                //is first specialization
struct Contains<CharSequence<First, Cs...>,First>: std::true_type {}; 
template<char Match>                            //not found specialization
struct Contains<CharSequence<>,Match>: std::false_type{};

template<int I, typename T, typename U> 
struct MakeSequence;                            //generic
template<int I, bool... Bs, typename U> 
struct MakeSequence<I,BoolSequence<Bs...>, U>:  //not last
    MakeSequence<I-1, BoolSequence<Contains<U,I-1>::value,Bs...>, U>{};
template<bool... Bs, typename U> 
struct MakeSequence<0,BoolSequence<Bs...>,U>{   //last  
    using Type = BoolSequence<Bs...>;
};
template<typename T> struct BoolASCIITable;
template<bool... Bs> struct BoolASCIITable<BoolSequence<Bs...>>{
    /* could be made constexpr but not yet supported by MSVC */
    static bool isDelim(const char c){
        static const bool table[256] = {Bs...};
        return table[static_cast<int>(c)];
    }   
};
using Delims = CharSequence<'.',',',' ',':','\n'>;  //list your custom delimiters here
using Table = BoolASCIITable<typename MakeSequence<256,BoolSequence<>,Delims>::Type>;

With that in place making a getNextToken function is easy:

template<typename T_It>
std::pair<T_It,T_It> getNextToken(T_It begin,T_It end){
    begin = std::find_if(begin,end,std::not1(Table{})); //find first non delim or end
    auto second = std::find_if(begin,end,Table{});      //find first delim or end
    return std::make_pair(begin,second);
}

Using it is also easy:

int main() {
    std::string s{"Some people, excluding those present, have been compile time constants - since puberty."};
    auto it = std::begin(s);
    auto end = std::end(s);
    while(it != std::end(s)){
        auto token = getNextToken(it,end);
        std::cout << std::string(token.first,token.second) << std::endl;
        it = token.second;
    }
    return 0;
}

Here is a live example: http://ideone.com/GKtkLQ

How to draw a custom UIView that is just a circle - iPhone app

Would I just override the drawRect method?

Yes:

- (void)drawRect:(CGRect)rect
{
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextAddEllipseInRect(ctx, rect);
    CGContextSetFillColor(ctx, CGColorGetComponents([[UIColor blueColor] CGColor]));
    CGContextFillPath(ctx);
}

Also, would it be okay to change the frame of that view within the class itself?

Ideally not, but you could.

Or do I need to change the frame from a different class?

I'd let the parent control that.

Check if input is number or letter javascript

You can use the isNaN function to determine if a value does not convert to a number. Example as below:

function checkInp()
{
  var x=document.forms["myForm"]["age"].value;
  if (isNaN(x)) 
  {
    alert("Must input numbers");
    return false;
  }
}

How to export and import a .sql file from command line with options?

mysqldump will not dump database events, triggers and routines unless explicitly stated when dumping individual databases;

mysqldump -uuser -p db_name --events --triggers --routines > db_name.sql

How to simulate POST request?

This should help if you need a publicly exposed website but you're on a dev pc. Also to answer (I can't comment yet): "How do I post to an internal only running development server with this? – stryba "

NGROK creates a secure public URL to a local webserver on your development machine (Permanent URLs available for a fee, temporary for free).
1) Run ngrok.exe to open command line (on desktop)
2) Type ngrok.exe http 80 to start a tunnel,
3) test by browsing to the displayed web address which will forward and display the local default 80 page on your dev pc

Then use some of the tools recommended above to POST to your ngrok site ('https://xxxxxx.ngrok.io') to test your local code.

https://ngrok.com/

Aborting a shell script if any command returns a non-zero value

The if statements in your example are unnecessary. Just do it like this:

dosomething1 || exit 1

If you take Ville Laurikari's advice and use set -e then for some commands you may need to use this:

dosomething || true

The || true will make the command pipeline have a true return value even if the command fails so the the -e option will not kill the script.

How to detect the device orientation using CSS media queries?

I would go for aspect-ratio, it offers way more possibilities.

/* Exact aspect ratio */
@media (aspect-ratio: 2/1) {
    ...
}

/* Minimum aspect ratio */
@media (min-aspect-ratio: 16/9) {
    ...
}

/* Maximum aspect ratio */
@media (max-aspect-ratio: 8/5) {
    ...
}

Both, orientation and aspect-ratio depend on the actual size of the viewport and have nothing todo with the device orientation itself.

Read more: https://dev.to/ananyaneogi/useful-css-media-query-features-o7f

How to import other Python files?

If the function defined is in a file x.py:

def greet():
    print('Hello! How are you?')

In the file where you are importing the function, write this:

from x import greet

This is useful if you do not wish to import all the functions in a file.

insert data into database using servlet and jsp in eclipse

String user = request.getParameter("uname");
out.println(user); 
String pass = request.getParameter("pass");
out.println(pass); 
Class.forName( "com.mysql.jdbc.Driver" );
Connection conn = DriverManager.getConnection( "jdbc:mysql://localhost:3306/rental","root","root" ) ;
out.println("hello");
Statement st = conn.createStatement();
String sql = "insert into login (user,pass) values('" + user + "','" + pass + "')";
st.executeUpdate(sql);

Assign keyboard shortcut to run procedure

According to Microsoft's documentation

  1. On the Tools menu, point to Macro, and then click Macros.

  2. In the Macro name box, enter the name of the macro you want to assign to a keyboard shortcut key.

  3. Click Options.

  4. If you want to run the macro by pressing a keyboard shortcut key, enter a letter in the Shortcut key box. You can use CTRL+ letter (for lowercase letters) or CTRL+SHIFT+ letter (for uppercase letters), where letter is any letter key on the keyboard. The shortcut key cannot use a number or special character, such as @ or #.

    Note: The shortcut key will override any equivalent default Microsoft Excel shortcut keys while the workbook that contains the macro is open.

  5. If you want to include a description of the macro, type it in the Description box.

  6. Click OK.

  7. Click Cancel.

What is the correct target for the JAVA_HOME environment variable for a Linux OpenJDK Debian-based distribution?

Updated answer that will solve your problem and also just a general good how-to for installing Oracle Java 7 on Ubuntu can be found here: http://www.wikihow.com/Install-Oracle-Java-on-Ubuntu-Linux

Define variable to use with IN operator (T-SQL)

As no one mentioned it before, starting from Sql Server 2016 you can also use json arrays and OPENJSON (Transact-SQL):

declare @filter nvarchar(max) = '[1,2]'

select *
from dbo.Test as t
where
    exists (select * from openjson(@filter) as tt where tt.[value] = t.id)

You can test it in sql fiddle demo

You can also cover more complicated cases with json easier - see Search list of values and range in SQL using WHERE IN clause with SQL variable?

LINQ to read XML

Or, if you want a more general approach - i.e. for nesting up to "levelN":

void Main()
{
    XElement rootElement = XElement.Load(@"c:\events\test.xml");

    Console.WriteLine(GetOutline(0, rootElement));  
}

private string GetOutline(int indentLevel, XElement element)
{
    StringBuilder result = new StringBuilder();

    if (element.Attribute("name") != null)
    {
        result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
    }

    foreach (XElement childElement in element.Elements())
    {
        result.Append(GetOutline(indentLevel + 1, childElement));
    }

    return result.ToString();
}

How can I send an inner <div> to the bottom of its parent <div>?

Here is way to avoid absolute divs and tables if you know parent's height:

<div class="parent">
    <div class="child"> <a href="#">Home</a>
    </div>
</div>

CSS:

.parent {
    line-height:80px;
    border: 1px solid black;
}
.child {
    line-height:normal;
    display: inline-block;
    vertical-align:bottom;
    border: 1px solid red;
}

JsFiddle:

Example

Adding a line break in MySQL INSERT INTO text

You can simply replace all \n with <br/> tag so that when page is displayed then it breaks line.

UPDATE table SET field = REPLACE(field, '\n', '<br/>')

"Could not load type [Namespace].Global" causing me grief

I had this issue when deploying on prod server only. In my other environments it works... I just deleted stuff in the bin folder then republish and it work after that.

What's the most efficient way to erase duplicates and sort a vector?

If you are looking for performance and using std::vector, I recommend the one that this documentation link provides.

std::vector<int> myvector{10,20,20,20,30,30,20,20,10};             // 10 20 20 20 30 30 20 20 10
std::sort(myvector.begin(), myvector.end() );
const auto& it = std::unique (myvector.begin(), myvector.end());   // 10 20 30 ?  ?  ?  ?  ?  ?
                                                                   //          ^
myvector.resize( std::distance(myvector.begin(),it) ); // 10 20 30

Uncaught SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode

This means that you must declare strict mode by writing "use strict" at the beginning of the file or the function to use block-scope declarations.

EX:

function test(){
    "use strict";
    let a = 1;
} 

How to putAll on Java hashMap contents of one to another, but not replace existing keys and values?

Java 8 solution using Map#merge

As of you can use Map#merge(K key, V value, BiFunction remappingFunction) which merges a value into the Map using remappingFunction in case the key is already found in the Map you want to put the pair into.

// using lambda
newMap.forEach((key, value) -> map.merge(key, value, (oldValue, newValue) -> oldValue));
// using for-loop
for (Map.Entry<Integer, String> entry: newMap.entrySet()) {
    map.merge(entry.getKey(), entry.getValue(), (oldValue, newValue) -> oldValue);
}

The code iterates the newMap entries (key and value) and each one is merged into map through the method merge. The remappingFunction is triggered in case of duplicated key and in that case it says that the former (original) oldValue value will be used and not rewritten.

With this solution, you don't need a temporary Map.


Let's have an example of merging newMap entries into map and keeping the original values in case of the duplicated antry.

Map<Integer, String> newMap = new HashMap<>();
newMap.put(2, "EVIL VALUE");                         // this will NOT be merged into
newMap.put(4, "four");                               // this WILL be merged into
newMap.put(5, "five");                               // this WILL be merged into

Map<Integer, String> map = new HashMap<>();
map.put(1, "one");
map.put(2, "two");
map.put(3, "three");

newMap.forEach((k, v) -> map.merge(k, v, (oldValue, newValue) -> oldValue));

map.forEach((k, v) -> System.out.println(k + " " + v));
1 one
2 two
3 three
4 four
5 five

How to use a wildcard in the classpath to add multiple jars?

If you mean that you have an environment variable named CLASSPATH, I'd say that's your mistake. I don't have such a thing on any machine with which I develop Java. CLASSPATH is so tied to a particular project that it's impossible to have a single, correct CLASSPATH that works for all.

I set CLASSPATH for each project using either an IDE or Ant. I do a lot of web development, so each WAR and EAR uses their own CLASSPATH.

It's ignored by IDEs and app servers. Why do you have it? I'd recommend deleting it.

How do I create a sequence in MySQL?

If You need sth different than AUTO_INCREMENT you can still use triggers.

jQuery set checkbox checked

Taking all of the proposed answers and applying them to my situation - trying to check or uncheck a checkbox based on a retrieved value of true (should check the box) or false (should not check the box) - I tried all of the above and found that using .prop("checked", true) and .prop("checked", false) were the correct solution.

I can't add comments or up answers yet, but I felt this was important enough to add to the conversation.

Here is the longhand code for a fullcalendar modification that says if the retrieved value "allDay" is true, then check the checkbox with ID "even_allday_yn":

if (allDay)
{
    $( "#even_allday_yn").prop('checked', true);
}
else
{
    $( "#even_allday_yn").prop('checked', false);
}

React Router Pass Param to Component

If you want to pass props to a component inside a route, the simplest way is by utilizing the render, like this:

<Route exact path="/details/:id" render={(props) => <DetailsPage globalStore={globalStore} {...props} /> } />

You can access the props inside the DetailPage using:

this.props.match
this.props.globalStore

The {...props} is needed to pass the original Route's props, otherwise you will only get this.props.globalStore inside the DetailPage.

Decompile Python 2.7 .pyc

UPDATE (2019-04-22) - It sounds like you want to use uncompyle6 nowadays rather than the answers I had mentioned originally.

This sounds like it works: http://code.google.com/p/unpyc/

Issue 8 says it supports 2.7: http://code.google.com/p/unpyc/updates/list

UPDATE (2013-09-03) - As noted in the comments and in other answers, you should look at https://github.com/wibiti/uncompyle2 or https://github.com/gstarnberger/uncompyle instead of unpyc.

Replace string in text file using PHP

Does this work:

$msgid = $_GET['msgid'];

$oldMessage = '';

$deletedFormat = '';

//read the entire string
$str=file_get_contents('msghistory.txt');

//replace something in the file string - this is a VERY simple example
$str=str_replace($oldMessage, $deletedFormat,$str);

//write the entire string
file_put_contents('msghistory.txt', $str);

Transform DateTime into simple Date in Ruby on Rails

I recently wrote a gem to simplify this process and to neaten up your views, etc etc.

Check it out at: http://github.com/platform45/easy_dates

Adding hours to JavaScript Date object?

You can use the momentjs http://momentjs.com/ Library.

var moment = require('moment');
foo = new moment(something).add(10, 'm').toDate();

Java using enum with switch statement

This should work in the way that you describe. What error are you getting? If you could pastebin your code that would help.

http://download.oracle.com/javase/tutorial/java/javaOO/enum.html

EDIT: Are you sure you want to define a static enum? That doesn't sound right to me. An enum is much like any other object. If your code compiles and runs but gives incorrect results, this would probably be why.

Ruby: Easiest Way to Filter Hash Keys?

This is a one line to solve the complete original question:

params.select { |k,_| k[/choice/]}.values.join('\t')

But most the solutions above are solving a case where you need to know the keys ahead of time, using slice or simple regexp.

Here is another approach that works for simple and more complex use cases, that is swappable at runtime

data = {}
matcher = ->(key,value) { COMPLEX LOGIC HERE }
data.select(&matcher)

Now not only this allows for more complex logic on matching the keys or the values, but it is also easier to test, and you can swap the matching logic at runtime.

Ex to solve the original issue:

def some_method(hash, matcher) 
  hash.select(&matcher).values.join('\t')
end

params = { :irrelevant => "A String",
           :choice1 => "Oh look, another one",
           :choice2 => "Even more strings",
           :choice3 => "But wait",
           :irrelevant2 => "The last string" }

some_method(params, ->(k,_) { k[/choice/]}) # => "Oh look, another one\\tEven more strings\\tBut wait"
some_method(params, ->(_,v) { v[/string/]}) # => "Even more strings\\tThe last string"

Having a UITextField in a UITableViewCell

I had been avoiding this by calling a method to run [cell.contentView bringSubviewToFront:textField] every time my cells appeared, but then I discovered this relatively simple technique:

cell.accessoryView = textField;

Doesn't seem to have the same background-overpasting issue, and it aligns itself on its own (somewhat). Also, the textLabel auto-truncates to avoid overflowing into (or under) it, which is handy.

Android checkbox style

Perhaps you want something like:

<style name="CustomActivityTheme" parent="@android:style/Theme.Holo">
    <item name="android:checkboxStyle">@style/customCheckBoxStyle</item>
</style>

<style name="customCheckBoxStyle" parent="@android:style/Widget.CompoundButton.CheckBox">
    <item name="android:textColor">@android:color/black</item>
</style>

Note, the textColor item.

SELECT COUNT in LINQ to SQL C#

Like that

var purchCount = (from purchase in myBlaContext.purchases select purchase).Count();

or even easier

var purchCount = myBlaContext.purchases.Count()

Having trouble setting working directory

Maybe it is the case that you have your path in couple of lines, you used enter to make it? If so, then part of you paths might look like that "/\nData/" instead of "/Data/", which causes the problem. Just set it to be in one line and issue is solved!

In Python, how do I split a string and keep the separators?

If you have only 1 separator, you can employ list comprehensions:

text = 'foo,bar,baz,qux'  
sep = ','

Appending/prepending separator:

result = [x+sep for x in text.split(sep)]
#['foo,', 'bar,', 'baz,', 'qux,']
# to get rid of trailing
result[-1] = result[-1].strip(sep)
#['foo,', 'bar,', 'baz,', 'qux']

result = [sep+x for x in text.split(sep)]
#[',foo', ',bar', ',baz', ',qux']
# to get rid of trailing
result[0] = result[0].strip(sep)
#['foo', ',bar', ',baz', ',qux']

Separator as it's own element:

result = [u for x in text.split(sep) for u in (x, sep)]
#['foo', ',', 'bar', ',', 'baz', ',', 'qux', ',']
results = result[:-1]   # to get rid of trailing

Cannot authenticate into mongo, "auth fails"

It appears the problem is that a user created via the method described in the mongo docs does not have permission to connect to the default database (test), even if that user was created with the "userAdminAnyDatabase" and "dbAdminAnyDatabase" roles.

Why is my CSS bundling not working with a bin deployed MVC4 app?

Just for history:

Check that all mentioned less/css files in bundle have Build Action = "Content".

There is no error if some files from bundle missing on destination server.

Integration Testing POSTing an entire object to Spring MVC controller

I think most of these solutions are far too complicated. I assume that in your test controller you have this

 @Autowired
 private ObjectMapper objectMapper;

If its a rest service

@Test
public void test() throws Exception {
   mockMvc.perform(post("/person"))
          .contentType(MediaType.APPLICATION_JSON)
          .content(objectMapper.writeValueAsString(new Person()))
          ...etc
}

For spring mvc using a posted form I came up with this solution. (Not really sure if its a good idea yet)

private MultiValueMap<String, String> toFormParams(Object o, Set<String> excludeFields) throws Exception {
    ObjectReader reader = objectMapper.readerFor(Map.class);
    Map<String, String> map = reader.readValue(objectMapper.writeValueAsString(o));

    MultiValueMap<String, String> multiValueMap = new LinkedMultiValueMap<>();
    map.entrySet().stream()
            .filter(e -> !excludeFields.contains(e.getKey()))
            .forEach(e -> multiValueMap.add(e.getKey(), (e.getValue() == null ? "" : e.getValue())));
    return multiValueMap;
}



@Test
public void test() throws Exception {
  MultiValueMap<String, String> formParams = toFormParams(new Phone(), 
  Set.of("id", "created"));

   mockMvc.perform(post("/person"))
          .contentType(MediaType.APPLICATION_FORM_URLENCODED)
          .params(formParams))
          ...etc
}

The basic idea is to - first convert object to json string to get all the field names easily - convert this json string into a map and dump it into a MultiValueMap that spring expects. Optionally filter out any fields you dont want to include (Or you could just annotate fields with @JsonIgnore to avoid this extra step)

Get client IP address via third party web service

    $.ajax({
        url: '//freegeoip.net/json/',
        type: 'POST',
        dataType: 'jsonp',
        success: function(location) {
            alert(location.ip);
        }
    });

This will work https too

CSS Disabled scrolling

Try using the following code snippet. This should solve your issue.

body, html { 
    overflow-x: hidden; 
    overflow-y: auto;
}

COALESCE with Hive SQL

If customer primary contact medium is email, if email is null then phonenumber, and if phonenumber is also null then address. It would be written using COALESCE as

coalesce(email,phonenumber,address) 

while the same in hive can be achieved by chaining together nvl as

nvl(email,nvl(phonenumber,nvl(address,'n/a')))

Resolving MSB3247 - Found conflicts between different versions of the same dependent assembly

As mentioned here, you need to remove the unused references and the warnings will go.

How can I convert a DateTime to an int?

Do you want an 'int' that looks like 20110425171213? In which case you'd be better off ToString with the appropriate format (something like 'yyyyMMddHHmmss') and then casting the string to an integer (or a long, unsigned int as it will be way more than 32 bits).

If you want an actual numeric value (the number of seconds since the year 0) then that's a very different calculation, e.g.

result = second
result += minute * 60
result += hour * 60 * 60
result += day * 60 * 60 * 24 

etc.

But you'd be better off using Ticks.

Java HashMap performance optimization / alternative

If the arrays in your posted hashCode are bytes, then you will likely end up with lots of duplicates.

a[0] + a[1] will always be between 0 and 512. adding the b's will always result in a number between 0 and 768. multiply those and you get an upper limit of 400,000 unique combinations, assuming your data is perfectly distributed among every possible value of each byte. If your data is at all regular, you likely have far less unique outputs of this method.

How to set up datasource with Spring for HikariCP?

I have recently migrated from C3P0 to HikariCP in a Spring and Hibernate based project and it was not as easy as I had imagined and here I am sharing my findings.

For Spring Boot see my answer here

I have the following setup

  • Spring 4.3.8+
  • Hiberante 4.3.8+
  • Gradle 2.x
  • PostgreSQL 9.5

Some of the below configs are similar to some of the answers above but, there are differences.

Gradle stuff

In order to pull in the right jars, I needed to pull in the following jars

//latest driver because *brettw* see https://github.com/pgjdbc/pgjdbc/pull/849
compile 'org.postgresql:postgresql:42.2.0'
compile('com.zaxxer:HikariCP:2.7.6') {
    //they are pulled in separately elsewhere
    exclude group: 'org.hibernate', module: 'hibernate-core'
}

// Recommended to use HikariCPConnectionProvider by Hibernate in 4.3.6+    
compile('org.hibernate:hibernate-hikaricp:4.3.8.Final') {
        //they are pulled in separately elsewhere, to avoid version conflicts
        exclude group: 'org.hibernate', module: 'hibernate-core'
        exclude group: 'com.zaxxer', module: 'HikariCP'
}

// Needed for HikariCP logging if you use log4j
compile('org.slf4j:slf4j-simple:1.7.25')  
compile('org.slf4j:slf4j-log4j12:1.7.25') {
    //log4j pulled in separately, exclude to avoid version conflict
    exclude group: 'log4j', module: 'log4j'
}

Spring/Hibernate based configs

In order to get Spring & Hibernate to make use of Hikari Connection pool, you need to define the HikariDataSource and feed it into sessionFactory bean as shown below.

<!-- HikariCP Database bean -->
<bean id="dataSource" class="com.zaxxer.hikari.HikariDataSource" destroy-method="close">
    <constructor-arg ref="hikariConfig" />
</bean>

<!-- HikariConfig config that is fed to above dataSource -->
<bean id="hikariConfig" class="com.zaxxer.hikari.HikariConfig">
        <property name="poolName" value="SpringHikariPool" />
        <property name="dataSourceClassName" value="org.postgresql.ds.PGSimpleDataSource" />
        <property name="maximumPoolSize" value="20" />
        <property name="idleTimeout" value="30000" />

        <property name="dataSourceProperties">
            <props>
                <prop key="serverName">localhost</prop>
                <prop key="portNumber">5432</prop>
                <prop key="databaseName">dbname</prop>
                <prop key="user">dbuser</prop>
                <prop key="password">dbpassword</prop>
            </props>
        </property>
</bean>

<bean class="org.springframework.orm.hibernate4.LocalSessionFactoryBean" id="sessionFactory">
        <!-- Your Hikari dataSource below -->
        <property name="dataSource" ref="dataSource"/>
        <!-- your other configs go here -->
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.connection.provider_class">org.hibernate.hikaricp.internal.HikariCPConnectionProvider</prop>
                <!-- Remaining props goes here -->
            </props>
        </property>
 </bean>

Once the above are setup then, you need to add an entry to your log4j or logback and set the level to DEBUG to see Hikari Connection Pool start up.

Log4j1.2

<!-- Keep additivity=false to avoid duplicate lines -->
<logger additivity="false" name="com.zaxxer.hikari">
    <level value="debug"/>
    <!-- Your appenders goes here -->
</logger>

Logback

Via application.properties in Spring Boot

debug=true
logging.level.com.zaxxer.hikari.HikariConfig=DEBUG 

Using logback.xml

<logger name="com.zaxxer.hikari" level="DEBUG" additivity="false">
    <appender-ref ref="STDOUT" />
</logger>

With the above you should be all good to go! Obviously you need to customize the HikariCP pool configs in order to get the performance that it promises.

Split string and get first value only

You can do it:

var str = "Doctor Who,Fantasy,Steven Moffat,David Tennant";

var title = str.Split(',').First();

Also you can do it this way:

var index = str.IndexOf(",");
var title = index < 0 ? str : str.Substring(0, index);

How do I iterate over a range of numbers defined by variables in Bash?

These are all nice but seq is supposedly deprecated and most only work with numeric ranges.

If you enclose your for loop in double quotes, the start and end variables will be dereferenced when you echo the string, and you can ship the string right back to BASH for execution. $i needs to be escaped with \'s so it is NOT evaluated before being sent to the subshell.

RANGE_START=a
RANGE_END=z
echo -e "for i in {$RANGE_START..$RANGE_END}; do echo \\${i}; done" | bash

This output can also be assigned to a variable:

VAR=`echo -e "for i in {$RANGE_START..$RANGE_END}; do echo \\${i}; done" | bash`

The only "overhead" this should generate should be the second instance of bash so it should be suitable for intensive operations.

Read a zipped file as a pandas DataFrame

For "zip" files, you can use import zipfile and your code will be working simply with these lines:

import zipfile
import pandas as pd
with zipfile.ZipFile("Crime_Incidents_in_2013.zip") as z:
   with z.open("Crime_Incidents_in_2013.csv") as f:
      train = pd.read_csv(f, header=0, delimiter="\t")
      print(train.head())    # print the first 5 rows

And the result will be:

X,Y,CCN,REPORT_DAT,SHIFT,METHOD,OFFENSE,BLOCK,XBLOCK,YBLOCK,WARD,ANC,DISTRICT,PSA,NEIGHBORHOOD_CLUSTER,BLOCK_GROUP,CENSUS_TRACT,VOTING_PRECINCT,XCOORD,YCOORD,LATITUDE,LONGITUDE,BID,START_DATE,END_DATE,OBJECTID
0  -77.054968548763071,38.899775938598317,0925135...                                                                                                                                                               
1  -76.967309569035052,38.872119553647011,1003352...                                                                                                                                                               
2  -76.996184958456539,38.927921847721443,1101010...                                                                                                                                                               
3  -76.943077541353617,38.883686046653935,1104551...                                                                                                                                                               
4  -76.939209158039446,38.892278093281632,1125028...

How to set proxy for wget?

After trying many tutorials to configure my Ubuntu 16.04 LTS behind a authenticated proxy, it worked with these steps:

Edit /etc/wgetrc:

$ sudo nano /etc/wgetrc

Uncomment these lines:

#https_proxy = http://proxy.yoyodyne.com:18023/
#http_proxy = http://proxy.yoyodyne.com:18023/
#ftp_proxy = http://proxy.yoyodyne.com:18023/
#use_proxy = on

Change http://proxy.yoyodyne.com:18023/ to http://username:password@domain:port/

IMPORTANT: If it still doesn't work, check if your password has special characters, such as #, @, ... If this is the case, escape them (for example, replace passw@rd with passw%40rd).

Is it possible to pass parameters programmatically in a Microsoft Access update query?

I just tested this and it works in Access 2010.

Say you have a SELECT query with parameters:

PARAMETERS startID Long, endID Long;
SELECT Members.*
FROM Members
WHERE (((Members.memberID) Between [startID] And [endID]));

You run that query interactively and it prompts you for [startID] and [endID]. That works, so you save that query as [MemberSubset].

Now you create an UPDATE query based on that query:

UPDATE Members SET Members.age = [age]+1
WHERE (((Members.memberID) In (SELECT memberID FROM [MemberSubset])));

You run that query interactively and again you are prompted for [startID] and [endID] and it works well, so you save it as [MemberSubsetUpdate].

You can run [MemberSubsetUpdate] from VBA code by specifying [startID] and [endID] values as parameters to [MemberSubsetUpdate], even though they are actually parameters of [MemberSubset]. Those parameter values "trickle down" to where they are needed, and the query does work without human intervention:

Sub paramTest()
    Dim qdf As DAO.QueryDef
    Set qdf = CurrentDb.QueryDefs("MemberSubsetUpdate")
    qdf!startID = 1  ' specify
    qdf!endID = 2    '     parameters
    qdf.Execute
    Set qdf = Nothing
End Sub

Google Maps API v3: Can I setZoom after fitBounds?

I use this to ensure the zoom level does not exceed a set level so that I know satellite images will be available.

Add a listener to the zoom_changed event. This has the added benefit of controlling the zoom control on the UI also.

Only execute setZoom if you need to, so an if statement is preferable to Math.max or to Math.min

   google.maps.event.addListener(map, 'zoom_changed', function() { 
      if ( map.getZoom() > 19 ) { 
        map.setZoom(19); 
      } 
    });
    bounds = new google.maps.LatLngBounds( ... your bounds ... )
    map.fitBounds(bounds);

To prevent zooming out too far:

   google.maps.event.addListener(map, 'zoom_changed', function() { 
      if ( map.getZoom() < 6 ) { 
        map.setZoom(6); 
      } 
    });
    bounds = new google.maps.LatLngBounds( ... your bounds ... )
    map.fitBounds(bounds);

Fatal error in launcher: Unable to create process using ""C:\Program Files (x86)\Python33\python.exe" "C:\Program Files (x86)\Python33\pip.exe""

I wrote a script to patch those exe. But the best way is to fix distutil itself.

"""Fix "Fatal error in launcher: Unable to create process using ..." error. Put me besides those EXE made by pip. (They are made by distutils, and used by pip)"""
import re
import sys
import os
from glob import glob


script_path = os.path.dirname(os.path.realpath(__file__))
real_int_path = sys.executable
_t = script_path.rpartition(os.sep)[0] + os.sep + 'python.exe'
if script_path.lower().endswith('scripts') and os.path.isfile(_t):
    real_int_path = _t

print('real interpreter path: ' + real_int_path)
print()

for i in glob('*.exe'):
    with open(i, 'rb+') as f:
        img = f.read()
        match = re.search(rb'#![a-zA-Z]:\\.+\.exe', img)
        if not match:
            print("can't fix file: " + i)
            continue
        int_path = match.group()[2:].decode()
        int_path_start = match.start() + 2
        int_path_end = match.end()

        if int_path.lower() == real_int_path.lower():
            continue
        print('fix interpreter path: %s in %s' % (int_path, i))
        f.seek(int_path_start)
        f.write(real_int_path.encode())
        f.write(img[int_path_end:])

How to import Swagger APIs into Postman?

  • Click on the orange button ("choose files")
  • Browse to the Swagger doc (swagger.yaml)
  • After selecting the file, a new collection gets created in POSTMAN. It will contain folders based on your endpoints.

You can also get some sample swagger files online to verify this(if you have errors in your swagger doc).

Setting focus to iframe contents

i had a similar problem where i was trying to focus on a txt area in an iframe loaded from another page. in most cases it work. There was an issue where it would fire in FF when the iFrame was loaded but before it was visible. so the focus never seemed to be set correctly.

i worked around this with a simular solution to cheeming's answer above

    var iframeID = document.getElementById("modalIFrame"); 
//focus the IFRAME element 
$(iframeID).focus(); 
//use JQuery to find the control in the IFRAME and set focus 
$(iframeID).contents().find("#emailTxt").focus(); 

JavaScript DOM remove element

In most browsers, there's a slightly more succinct way of removing an element from the DOM than calling .removeChild(element) on its parent, which is to just call element.remove(). In due course, this will probably become the standard and idiomatic way of removing an element from the DOM.

The .remove() method was added to the DOM Living Standard in 2011 (commit), and has since been implemented by Chrome, Firefox, Safari, Opera, and Edge. It was not supported in any version of Internet Explorer.

If you want to support older browsers, you'll need to shim it. This turns out to be a little irritating, both because nobody seems to have made a all-purpose DOM shim that contains these methods, and because we're not just adding the method to a single prototype; it's a method of ChildNode, which is just an interface defined by the spec and isn't accessible to JavaScript, so we can't add anything to its prototype. So we need to find all the prototypes that inherit from ChildNode and are actually defined in the browser, and add .remove to them.

Here's the shim I came up with, which I've confirmed works in IE 8.

(function () {
    var typesToPatch = ['DocumentType', 'Element', 'CharacterData'],
        remove = function () {
            // The check here seems pointless, since we're not adding this
            // method to the prototypes of any any elements that CAN be the
            // root of the DOM. However, it's required by spec (see point 1 of
            // https://dom.spec.whatwg.org/#dom-childnode-remove) and would
            // theoretically make a difference if somebody .apply()ed this
            // method to the DOM's root node, so let's roll with it.
            if (this.parentNode != null) {
                this.parentNode.removeChild(this);
            }
        };

    for (var i=0; i<typesToPatch.length; i++) {
        var type = typesToPatch[i];
        if (window[type] && !window[type].prototype.remove) {
            window[type].prototype.remove = remove;
        }
    }
})();

This won't work in IE 7 or lower, since extending DOM prototypes isn't possible before IE 8. I figure, though, that on the verge of 2015 most people needn't care about such things.

Once you've included them shim, you'll be able to remove a DOM element element from the DOM by simply calling

element.remove();

Can someone explain Microsoft Unity?

I just watched the 30 minute Unity Dependency Injection IoC Screencast by David Hayden and felt that was a good explaination with examples. Here is a snippet from the show notes:

The screencast shows several common usages of the Unity IoC, such as:

  • Creating Types Not In Container
  • Registering and Resolving TypeMappings
  • Registering and Resolving Named TypeMappings
  • Singletons, LifetimeManagers, and the ContainerControlledLifetimeManager
  • Registering Existing Instances
  • Injecting Dependencies into Existing Instances
  • Populating the UnityContainer via App.config / Web.config
  • Specifying Dependencies via Injection API as opposed to Dependency Attributes
  • Using Nested ( Parent-Child ) Containers

store return json value in input hidden field

If you use the JSON Serializer, you can simply store your object in string format as such

myHiddenText.value = JSON.stringify( myObject );

You can then get the value back with

myObject = JSON.parse( myHiddenText.value );

However, if you're not going to pass this value across page submits, it might be easier for you, and you'll save yourself a lot of serialization, if you just tuck it away as a global javascript variable.

How can I run a program from a batch file without leaving the console open after the program starts?

Here is my preferred solution. It is taken from an answer to a similar question.

Use a VBS Script to call the batch file:

Set WshShell = CreateObject("WScript.Shell")
WshShell.Run chr(34) & "C:\path\to\your\batchfile.bat" & Chr(34), 0
Set WshShell = Nothing

Copy the lines above to an editor and save the file with .VBS extension.

How does Django's Meta class work?

Answers that claim Django model's Meta and metaclasses are "completely different" are misleading answers.

The construction of Django model class objects, that is to say the object that stands for the class definition itself (yes, classes are also objects), are indeed controlled by a metaclass called ModelBase, and you can see that code here.

And one of the things that ModelBase does is to create the _meta attribute on every Django model which contains validation machinery, field details, save logic and so forth. During this operation, the stuff that is specified in the model's inner Meta class is read and used within that process.

So, while yes, in a sense Meta and metaclasses are different 'things', within the mechanics of Django model construction they are intimately related; understanding how they work together will deepen your insight into both at once.

This might be a helpful source of information to better understand how Django models employ metaclasses.

https://code.djangoproject.com/wiki/DevModelCreation

And this might help too if you want to better understand how objects work in general.

https://docs.python.org/3/reference/datamodel.html

How do I refresh a DIV content?

This one $("#yourDiv").load(" #yourDiv > *"); is the best if you are planning to just reload a <div>

Make sure to use an id and not a class. Also, remember to paste <script src="https://code.jquery.com/jquery-3.5.1.js"></script> in the <head> section of the html file, if you haven't already. In opposite case it won't work.

Display image at 50% of its "native" size

This should work:

img {
    max-width: 50%;
    height: auto;
}

excel VBA run macro automatically whenever a cell is changed

In an attempt to spot a change somewhere in a particular column (here in "W", i.e. "23"), I modified Peter Alberts' answer to:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Target.Column = 23 Then Exit Sub
    Application.EnableEvents = False             'to prevent endless loop
    On Error GoTo Finalize                       'to re-enable the events
    MsgBox "You changed a cell in column W, row " & Target.Row
    MsgBox "You changed it to: " & Target.Value
Finalize:
    Application.EnableEvents = True
End Sub

how to access downloads folder in android?

If you're using a shell, the filepath to the Download (no "s") folder is

/storage/emulated/0/Download

Including external jar-files in a new jar-file build with Ant

Two options, either reference the new jars in your classpath or unpack all classes in the enclosing jars and re-jar the whole lot! As far as I know packaging jars within jars is not recommeneded and you'll forever have the class not found exception!

Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of `ListView`

Assuming the renderDetailItem method has the following signature...

(rowData, sectionID, rowID, highlightRow) 

Try doing this...

<TouchableHighlight key={rowID} underlayColor='#dddddd'>

How to know Laravel version and where is it defined?

run php artisan --version from your console.

The version string is defined here:

https://github.com/laravel/framework/blob/master/src/Illuminate/Foundation/Application.php

/**
 * The Laravel framework version.
 *
 * @var string
 */
 const VERSION = '5.5-dev';

Replace specific text with a redacted version using Python

You can do it using named-entity recognition (NER). It's fairly simple and there are out-of-the-shelf tools out there to do it, such as spaCy.

NER is an NLP task where a neural network (or other method) is trained to detect certain entities, such as names, places, dates and organizations.

Example:

Sponge Bob went to South beach, he payed a ticket of $200!
I know, Michael is a good person, he goes to McDonalds, but donates to charity at St. Louis street.

Returns:

NER with spacy

Just be aware that this is not 100%!

Here are a little snippet for you to try out:

import spacy

phrases = ['Sponge Bob went to South beach, he payed a ticket of $200!', 'I know, Michael is a good person, he goes to McDonalds, but donates to charity at St. Louis street.']
nlp = spacy.load('en')
for phrase in phrases:
   doc = nlp(phrase)
   replaced = ""
   for token in doc:
      if token in doc.ents:
         replaced+="XXXX "
      else:
         replaced+=token.text+" "

Read more here: https://spacy.io/usage/linguistic-features#named-entities

You could, instead of replacing with XXXX, replace based on the entity type, like:

if ent.label_ == "PERSON":
   replaced += "<PERSON> "

Then:

import re, random

personames = ["Jack", "Mike", "Bob", "Dylan"]

phrase = re.replace("<PERSON>", random.choice(personames), phrase)

Take a full page screenshot with Firefox on the command-line

Firefox Screenshots is a new tool that ships with Firefox. It is not a developer tool, it is aimed at end-users of the browser.

To take a screenshot, click on the page actions menu in the address bar, and click "take a screenshot". If you then click "Save full page", it will save the full page, scrolling for you.


(source: mozilla.net)

iterate through a map in javascript

Don't use iterators to do this. Maintain your own loop by incrementing a counter in the callback, and recursively calling the operation on the next item.

$.each(myMap, function(_, arr) {
    processArray(arr, 0);
});

function processArray(arr, i) {
    if (i >= arr.length) return;

    setTimeout(function () {
        $('#variant').fadeOut("slow", function () {
            $(this).text(i + "-" + arr[i]).fadeIn("slow");

            // Handle next iteration
            processArray(arr, ++i);
        });
    }, 6000);
}

Though there's a logic error in your code. You're setting the same container to more than one different value at (roughly) the same time. Perhaps you mean for each one to update its own container.

AWS S3 - How to fix 'The request signature we calculated does not match the signature' error?

Just to add to the many different ways this can show up.

If you using safari on iOS and you are connected to the Safari Technology Preview console - you will see the same problem. If you disconnect from the console - the problem will go away.

Of course it makes troubleshooting other issues difficult but it is a 100% repro.

I am trying to figure out what I can change in STP to stop it from doing this but have not found it yet.

Sending HTML Code Through JSON

In PHP:

$data = "<html>....";
exit(json_encode($data));

Then you should use AJAX to retrieve the data and do what you want with it. I suggest using JQuery: http://api.jquery.com/jQuery.getJSON/

What does 'killed' mean when a processing of a huge CSV with Python, which suddenly stops?

Exit code 137 (128+9) indicates that your program exited due to receiving signal 9, which is SIGKILL. This also explains the killed message. The question is, why did you receive that signal?

The most likely reason is probably that your process crossed some limit in the amount of system resources that you are allowed to use. Depending on your OS and configuration, this could mean you had too many open files, used too much filesytem space or something else. The most likely is that your program was using too much memory. Rather than risking things breaking when memory allocations started failing, the system sent a kill signal to the process that was using too much memory.

As I commented earlier, one reason you might hit a memory limit after printing finished counting is that your call to counter.items() in your final loop allocates a list that contains all the keys and values from your dictionary. If your dictionary had a lot of data, this might be a very big list. A possible solution would be to use counter.iteritems() which is a generator. Rather than returning all the items in a list, it lets you iterate over them with much less memory usage.

So, I'd suggest trying this, as your final loop:

for key, value in counter.iteritems():
    writer.writerow([key, value])

Note that in Python 3, items returns a "dictionary view" object which does not have the same overhead as Python 2's version. It replaces iteritems, so if you later upgrade Python versions, you'll end up changing the loop back to the way it was.

How to download file from database/folder using php

here is the code to download file with how much % it is downloaded

<?php
$ch = curl_init();
$downloadFile = fopen( 'file name here', 'w' );
curl_setopt($ch, CURLOPT_URL, "file link here");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_BUFFERSIZE, 65536);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, 'downloadProgress'); 
curl_setopt($ch, CURLOPT_NOPROGRESS, false);
curl_setopt( $ch, CURLOPT_FILE, $downloadFile );
curl_exec($ch);
curl_close($ch);

function downloadProgress ($resource, $download_size, $downloaded_size, $upload_size, $uploaded_size) {

    if($download_size!=0){
    $percen= (($downloaded_size/$download_size)*100);
    echo $percen."<br>";

}

}
?>

How to use @Nullable and @Nonnull annotations more effectively?

What I do in my projects is to activate the following option in the "Constant conditions & exceptions" code inspection:
Suggest @Nullable annotation for methods that may possibly return null and report nullable values passed to non-annotated parameters Inspections

When activated, all non-annotated parameters will be treated as non-null and thus you will also see a warning on your indirect call:

clazz.indirectPathToA(null); 

For even stronger checks the Checker Framework may be a good choice (see this nice tutorial.
Note: I have not used that yet and there may be problems with the Jack compiler: see this bugreport

python numpy ValueError: operands could not be broadcast together with shapes

It's possible that the error didn't occur in the dot product, but after. For example try this

a = np.random.randn(12,1)
b = np.random.randn(1,5)
c = np.random.randn(5,12)
d = np.dot(a,b) * c

np.dot(a,b) will be fine; however np.dot(a, b) * c is clearly wrong (12x1 X 1x5 = 12x5 which cannot element-wise multiply 5x12) but numpy will give you

ValueError: operands could not be broadcast together with shapes (12,1) (1,5)

The error is misleading; however there is an issue on that line.

How to create cross-domain request?

In my experience the plugins worked with http but not with the latest httpClient. Also, configuring the CORS respsonse headers on the server wasn't really an option. So, I created a proxy.conf.json file to act as a proxy server.

Read more about this here: https://github.com/angular/angular-cli/blob/master/docs/documentation/stories/proxy.md

below is my prox.conf.json file

{
  "/posts": {
    "target": "https://example.com",
    "secure": true,
    "pathRewrite": {
    "^/posts": ""
  },
    "changeOrigin": true
  }
}

I placed the proxy.conf.json file right next the the package.json file in the same directory

then I modified the start command in the package.json file like below

"start": "ng serve --proxy-config proxy.conf.json"

now, the http call from my app component is as follows

return this._http.get('/posts/pictures?method=GetPictures')
.subscribe((returnedStuff) => {
  console.log(returnedStuff);
});

Lastly to run my app, I'd have to use npm start or ng serve --proxy-config proxy.conf.json

How to change an input button image using CSS?

Perhaps you could just import a .js file as well and have the image replacement there, in JavaScript.

How to force NSLocalizedString to use a specific language

I like best Mauro Delrio's method. I also have added the following in my Project_Prefix.pch

#import "Language.h"    
#define MyLocalizedString(key, alt) [Language get:key alter:alt]

So if you ever want to use the standard method (that uses NSLocalizedString) you can make a quick syntax substitution in all files.

Conditional Formatting (IF not empty)

This method works for Excel 2016, and calculates on cell value, so can be used on formula arrays (i.e. it will ignore blank cells that contain a formula).

  • Highlight the range.
  • Home > Conditional Formatting > New Rule > Use a Formula.
  • Enter "=LEN(#)>0" (where '#' is the upper-left-most cell in your range).
  • Alter the formatting to suit your preference.

Note: Len(#)>0 be altered to only select cell values above a certain length.

Note 2: '#' must not be an absolute reference (i.e. shouldn't contain '$').