PHP Exec Not running, but command works ok!

Question

I have the following script to take an uploaded PDF in PHP and call ImageMagik/Ghostscript to convert to images of specified size.

$tmp = exec("convert \"{$strPDF}\" -resize 500X500 \"{$strOut}\"", $results);

However, this doesnt seem to work. No errors in the log file and no errors on screen. If I do the following,

$tmp = exec("convert \"{$strPDF}\" -resize 500X500 \"{$strOut}\"", $results); 
echo ("convert \"{$strPDF}\" -resize 500X500 \"{$strOut}\"");

And I paste the output into a command prompt it works fine (It takes around 6-10 seconds - My max_execution_time is at 600.

Any suggestions on why this might not be working?

This is Windows, IIS 7 and PHP5.

Edit: I'm having the same issue in both CentOS and Windows. Both have ImageMagik and Ghostscript installed.

Edit Edit the below still fails.

$handle = popen("convert \"{$strPDF}\" -resize 500X500 \"{$strOut}\"","r");
        echo "'$handle'; " . gettype($handle) . "\n";
        $read = fread($handle, 2096);
        echo $read;
        pclose($handle);

You are asking for trouble by putting variables directly in the command line. **CLI Injection** is as dangerous, if not more dangerous than *SQL Injection*. Use [`escapeshellarg()`](http://php.net/escapeshellarg). — Andrew Moore, Sep 06 '10 at 14:47
Try using popen instead of exec and read the output (with fgets) — Milan Babuškov, Sep 06 '10 at 15:24
@Milan Babuškov Same issue. :( Updated main post with code. — LiamB, Sep 06 '10 at 15:33

score 10 · Answer 1 · edited May 23 '17 at 12:24

10

Try adding 2>&1 to the end of your command. I found it here.

exec('some_command 2>&1', $output);
print_r($output);  // to see the respond to your command

edited May 23 '17 at 12:24

Community

1
1

answered Dec 28 '14 at 21:27

user

101
1
3

score 3 · Accepted Answer · answered Sep 06 '10 at 14:40

3

in php.ini maybe this function exec declare under

disable_functions

or if you run in

safe mode

This function is disabled when PHP is running in safe mode.

answered Sep 06 '10 at 14:40

Haim Evgi

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(safe_mode = Off and disable_functions = ) So doesnt look like it is that. – LiamB Sep 06 '10 at 14:50
maybe permission on this file or this directory – Haim Evgi Sep 06 '10 at 14:52

score 1 · Answer 3 · answered Sep 06 '10 at 15:47

1

Could it be an issue with your PATH variable ?

You might want to try and run

<?php
echo exec('cmd.exe /c echo %path%');
?>

both in the command line and from IIS and compare their outputs.

answered Sep 06 '10 at 15:47

Arc

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Might help if you try using absolute paths in this case (especially if even "cmd.exe" does not execute). – Arc Sep 09 '10 at 12:05

PHP Exec Not running, but command works ok!

3 Answers3

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