What about:

    @echo off
    set myvar=&quot;the list: &quot;
    for /r %%i in (*.doc) DO call :concat %%i
    echo %myvar%
    goto :eof
    
    :concat
    set myvar=%myvar% %1;
    goto :eof


Based on Rubens&#39; solution, you need to enable Delayed Expansion of env variables (type &quot;help setlocal&quot; or &quot;help cmd&quot;) so that the var is correctly evaluated in the loop:

    @echo off
    setlocal enabledelayedexpansion
    set myvar=the list: 
    for /r %%i In (*.sql) DO set myvar=!myvar! %%i,
    echo %myvar%

Also consider the following restriction ([MSDN][1]):

&gt; The maximum individual environment
&gt; variable size is 8192bytes.

 

  [1]: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/ntcmds_shelloverview.mspx?mfr=true

Note that the variables `@fname` or `@ext` can be simply concatenated. This:

    forfiles /S /M *.pdf /C &quot;CMD /C REN @path @fname_old.@ext&quot;

renames all PDF files to &quot;filename_old.pdf&quot;

I had this weird experience with problem number 10 on [Project Euler][1] (great site by the way). The assignment was to calculate the sum of all the prime numbers below two million.

I used an int for the sum, and my algorith produced an answer, but when i pasted it to verify the answer, it was wrong.

It turned out that the result was too big to fit in an int, but wouldn&#39;t this cause an overflow error or something? Instead, it just returned a value far off from the real answer.

When I changed the type to long, everything was hunky dory.


  [1]: http://projecteuler.net/

No overflow exception for int in C#?

I generally use `cout` and `cerr` to write text to the console. However sometimes I find it easier to use the good old `printf` statement. I use it when I need to format the output. 

One example of where I would use this is:

    // Lets assume that I&#39;m printing coordinates... 
    printf(&quot;(%d,%d)\n&quot;, x, y);

    // To do the same thing as above using cout....
    cout &lt;&lt; &quot;(&quot; &lt;&lt; x &lt;&lt; &quot;,&quot; &lt;&lt; y &lt;&lt; &quot;)&quot; &lt;&lt; endl;

I know I can format output using `cout` but I already know how to use the `printf`. Is there any reason I shouldn&#39;t use the `printf` statement?

Should I use printf in my C++ code?

I have a directory for which I want to list all the `.doc` files with a `;`.

I know the following batch command echos all the files:
    
    for /r %%i In (*.doc) DO echo %%i

But now I want to put them all in a variable, add a `;` in between and echo them all at once.  
How can I do that?

    set myvar=&quot;the list: &quot;
    for /r %%i In (*.doc) DO &lt;what?&gt;
    echo %myvar%

How to concatenate strings in a Windows batch file?

I have a directory for which I want to list all the <code>.doc</code> files with a <code>;</code>.
I know the following batch command echos all the files:
<pre><code class="hljs language-bash">for /r %%i In (*.doc) DO echo %%i
</code></pre>
But now I want to put them all in a variable, add a <code>;</code> in between and echo them all at once. 
How can I do that?
<pre><code class="hljs language-bash">set myvar="the list: "
for /r %%i In (*.doc) DO &#x3C;what?>
echo %myvar%
</code></pre>

How do I run a PowerShell script?

  * I have a script named myscript.ps1
  * I have all the necessary frameworks installed
  * I set that [execution policy][1] thing
  * I have followed the instructions on [this MSDN help page][2]
    and am trying to run it like so:
    `powershell.exe &#39;C:\my_path\yada_yada\run_import_script.ps1&#39;` (with or without `--noexit`)

which returns exactly nothing, except that the file name is output.

No error, no message, nothing. Oh, when I add `-noexit`, the same thing happens, but I remain within PowerShell and have to exit manually.

The .ps1 file is supposed to run a program and return the error level dependent on that program&#39;s output. But I&#39;m quite sure I&#39;m not even getting there yet.

What am I doing wrong?

  [1]: https://stackoverflow.com/questions/10635/why-dont-my-powershell-scripts-run
  [2]: http://technet.microsoft.com/en-us/library/ee176949.aspx


How to run a PowerShell script

I am running a PowerShell script from within a batch file. The script fetches a web page and checks whether the page&#39;s content is the string &quot;OK&quot;.

The PowerShell script returns an error level to the batch script.

The batch script is executed by [ScriptFTP][1], an FTP automation program. If an error occurs, I can have ScriptFTP send the full console output to the administrator via E-Mail.

In the PowerShell script, I would like to output the return value from the web site if it is not &quot;OK&quot;, so the error message gets included in the console output, and thus in the status mail.

I am new to PowerShell and not sure which output function to use for this. I can see three:

  * Write-Host
  * Write-Output
  * Write-Error

What would be the right thing to use to write to the Windows equivalent of `stdout`?


  [1]: http://www.scriptftp.com

How to output something in PowerShell

I know that the `color bf` command sets the colors of the whole command line window but I wanted to to print one single line in a different color.

How to echo with different colors in the Windows command line

How do I determine a mapped drive&#39;s actual path?

So if I have a mapped drive on a machine called &quot;Z&quot; how can I using .NET determine the machine and path for the mapped folder?

The code can assume it&#39;s running on the machine with the mapped drive.


I looked at Path, Directory, FileInfo objects, but can&#39;t seem to find anything.

I also looked for existing questions, but could not find what I&#39;m looking for.


How do I determine a mapped drive&#39;s actual path?

How do I get the current username in Windows PowerShell?



I have an Excel VBA macro which I need to run when accessing the file from a batch file, but not every time I open it (hence not using the open file event). Is there a way to run the macro from the command line or batch file? I&#39;m not familiar with such a command.

Assume a Windows NT environment.

Way to run Excel macros from command line or batch file?

How would you implement logical operators in DOS Batch files?

Logical operators (&quot;and&quot;, &quot;or&quot;) in DOS batch

Is it possible in Windows batch file to call more than one command in a **single** `FOR` loop? Let&#39;s say for example I want to print the file name and after delete it:

    @ECHO OFF
    FOR /r %%X IN (*.txt) DO (ECHO %%X DEL %%X)
    REM the line above is invalid syntax.

I know in this case I could solve it by doing two distinct FOR loops: one for showing the name and one for deleting the file, but is it possible to do it in one loop only?


Windows batch: call more than one command in a FOR loop?

I need to assign the output of a program to a variable using a MS batch file.

So in GNU Bash shell I would use `VAR=$(application arg0 arg1)`. I need a similar behavior in Windows using a batch file.

Something like `set VAR=application arg0 arg1`.

Assign output of a program to a variable using a MS batch file

I want append to a string so that every time I loop over it, it will add &quot;test&quot; to the string.


Like in `PHP` you would do:
    
    $teststr = &quot;test1\n&quot;
    $teststr .= &quot;test2\n&quot;
    echo = &quot;$teststr&quot;
Returns:
 
    test1
    test2
    
But I need to do this in a shell script

How do you append to an already existing string?

Is there a C++ Standard Template Library class that provides efficient string concatenation functionality, similar to C#&#39;s [StringBuilder][1] or Java&#39;s [StringBuffer][2]?


  [1]: http://msdn.microsoft.com/en-us/library/system.text.stringbuilder.aspx
  [2]: http://java.sun.com/j2se/1.5.0/docs/api/java/lang/StringBuffer.html

C++ equivalent of StringBuffer/StringBuilder?

I am creating a computed column across fields of which some are potentially null.

The problem is that if any of those fields is null, the entire computed column will be null. I understand from the Microsoft documentation that this is expected and can be turned off via the setting SET CONCAT_NULL_YIELDS_NULL. However, there I don&#39;t want to change this default behavior because I don&#39;t know its implications on other parts of SQL Server.

Is there a way for me to just check if a column is null and only append its contents within the computed column formula if its not null?

SQL Server String Concatenation with Null

I have this code:

    a = &quot;xyz&quot;  
    g = &quot;abcd &quot; &amp; a  

After running it, the value of `g` is `abcd xyz`.

However, I want quotes around the value of `a` in `g`. After running the code, `g` should be `abcd &quot;xyz&quot;` instead.

How can I accomplish this?

Adding quotes to a string in VBScript

In VB.NET, is there any advantage to using `&amp;` to concatenate strings instead of `+`?

For example

    Dim x as String = &quot;hello&quot; + &quot; there&quot;

vs.

    Dim x as String = &quot;hello&quot; &amp; &quot; there&quot;

Yes, I know for a lot of string concatenations I&#39;d want to use `StringBuilder`, but this is more of a general question.


Content Type	Original Author	Original Content on Stackoverflow
Question	Fortega	View Question on Stackoverflow
Solution 1 - Windows	Rubens Farias	View Answer on Stackoverflow
Solution 2 - Windows	devio	View Answer on Stackoverflow
Solution 3 - Windows	Pierre	View Answer on Stackoverflow

How to concatenate strings in a Windows batch file?

Windows Problem Overview

Windows Solutions

Solution 1 - Windows

Solution 2 - Windows

Solution 3 - Windows

Should I use printf in my C++ code?

No overflow exception for int in C#?

Attributions