Anyone else have trouble with using exec() on a shared host?

[littlejim84]

Hello there.

I have reseller space using a shared hosting solution from UnitedHosting.co.uk

I have started to use the ImageMagick command through exec() on one of my clients sites, here is a cut down simplified bit of code that I execute:

exec("/usr/bin/convert /var/www/html/demo/mysite/images/uploaded/example.jpg -resize 120x120 /var/www/html/demo/mysite/images/uploaded/small_example.jpg");

I want this code to get a file and then resize with the prefix 'small_' on it.

Thing I seem to be noticing though, is it will work one minute, but then may not work at all at other times. Do you reckon this could be a problem with the shared hosting? Is there usually queues on running exec() commands on a shared host? Has anyone else had this problem? Does anyone know how I can get round it?

Any ideas/experiences/views would be much appriciated!
Little Jim

[spikeZ]

Hi Jim,
I am also fluffing about with Imagemagick and so far haven't managed to get exec() to do a darn thing!

I found that using the backtick operator worked for me.

so something like:

$image = `identify -verbose IM2`;

works fine.

[littlejim84]

Hello spikeZ, thanks for your reply.

I don't get what this backtick operator does? What is it meant to do? (A nice simple description would be wicked!)

[spikeZ]

Right then, the backtick operator attempts to run a shell exec command based on what is inside the ticks.

So in your script you have

exec("/usr/bin/convert /var/www/html/demo/mysite/images/uploaded/example.jpg -resize 120x120 /var/www/html/demo/mysite/images/uploaded/small_example.jpg");

wheras with a backtick operator it would be:

`/usr/bin/convert /var/www/html/demo/mysite/images/uploaded/example.jpg -resize 120x120 /var/www/html/demo/mysite/images/uploaded/small_example.jpg`;

Basically does the same thing as shell_exec and exec by attempting to execute the program or command it is given.

[littlejim84]

Ok, thanks for the explaination.

I suppose the next question would be, whats the benefits/reasons of using the backtick operator instead of the normal exec?

Many thanks again for your feedback.