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(). — Andrew Moore
– Andrew Moore, Commented Sep 6, 2010 at 14:47
Try using popen instead of exec and read the output (with fgets) — Milan Babuškov
– Milan Babuškov, Commented Sep 6, 2010 at 15:24
@Milan Babuškov Same issue. :( Updated main post with code. — LiamB
– LiamB, Commented Sep 6, 2010 at 15:33

Community · Accepted Answer · 2017-05-23 12:24:30Z

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, 2017 at 12:24

CommunityBot

11 silver badge

answered Dec 28, 2014 at 21:27

user

1011 silver badge3 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Haim Evgi · Accepted Answer · 2010-09-06 14:40:56Z

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 6, 2010 at 14:40

Haim Evgi

126k46 gold badges222 silver badges226 bronze badges

2 Comments

LiamB Over a year ago

(safe_mode = Off and disable_functions = ) So doesnt look like it is that.

Haim Evgi Over a year ago

maybe permission on this file or this directory

Arc · Accepted Answer · 2010-09-06 15:47:56Z

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 6, 2010 at 15:47

Arc

11.4k4 gold badges56 silver badges76 bronze badges

1 Comment

Arc Over a year ago

Might help if you try using absolute paths in this case (especially if even "cmd.exe" does not execute).

Collectives™ on Stack Overflow

PHP Exec Not running, but command works ok!

3 Answers 3

Comments

2 Comments

1 Comment

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

1 Comment

Linked

Related