My feeling is that you are not seeing the error channel. Perhaps it is being logged in the error_log of teh web server.
try redirecting the channel by seting up a specific log for that specific PHP script.
I have not done this myself, but I have notes on it, from the setup of PHP on a webserver.
http://www.ict.griffith.edu.au/anthony/ ... /php.hints
Also have you tried running the PHP from command line to see what it does?
For example... "test.php"
Code: Select all
<?php
system("convert -verbose logo: -thumbnail '50x50>' result.png");
?>
now run it
Code: Select all
LOGO GIF 640x480 640x480+0+0 8-bit PseudoClass 256c 31.7KB 0.000u 0:00.009
logo:=>LOGO GIF 640x480 640x480+0+0 8-bit PseudoClass 256c 31.7KB 0.000u 0:00.000
logo:=>result.png GIF 640x480=>50x38 8-bit DirectClass 0.020u 0:00.020
STOP PRESS
Looking at the PHP function manual for system()
http://au.php.net/manual/en/function.system.php
Has a major Warning
With safe mode enabled, the command string is escaped with escapeshellcmd(). Thus, echo y | echo x becomes echo y \| echo x.
This means PHP in safe mode may be doing some very unexpected things with the arguments.
Try prepending "echo" to the start (or some other 'list command arguments' program) and see what the argument are actually being received.
ASIDE: it pays to look though comments!