Check if PDFTOHTML is installed on server

Question

I'm trying to check before running a php script if pdftohtml is installed on server.

Is there a way to check if pdftohtml is installed on server (linux or mac) from within the code.

I'm looking for something similar to function_exists()

What have you tried so far? Where are you stuck? Anything wrong in using `file_exists`? — Nico Haase, Dec 08 '20 at 11:11
How to check with file_exists for something installed on server ? I'm stuck with how to do this .. :) — Szekelygobe, Dec 08 '20 at 11:15
I'm trying `shell_exec(phptohtml -v)` to return the version if installed , error if not. — Szekelygobe, Dec 08 '20 at 11:18
So, what have you tried so far? What are the requirements for your task? Find that binary anywhere? Why not let the user configure it? Why not install it using Composer to ensure that it is present? — Nico Haase, Dec 08 '20 at 11:18
@NicoHaase: I need to run a script, so I need to check bifore if PDFTOHTML is available. — Szekelygobe, Dec 08 '20 at 11:26
Look this link, I think it will help you: https://stackoverflow.com/questions/12424787/how-to-check-if-a-shell-command-exists-from-php — NRE, Dec 08 '20 at 11:26

score 1 · Accepted Answer · answered Dec 08 '20 at 11:27

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Perhaps, the following will solve your case:

$isInstalled = (bool) shell_exec('which pdftohtml');

which returns nothing if the program isn't found. But it will only work if it's installed globally (without specifying an absolute path). And returns a full path if it's there

answered Dec 08 '20 at 11:27

Fogus

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for some reason `shell_exec` it doesn't return a value. I also tried `shell_exec('pdftohtml -v')`. If I run the command in the terminal then it returns a value. – Szekelygobe Dec 08 '20 at 11:32
It seems `pdftohtml` doesn't exist on the server. Check something else: `shell_exec('which which')` – Fogus Dec 08 '20 at 11:34
If I run the command in terminal `which pdftohtml` then it returns the path `/usr/local/bin/pdftohtml` – Szekelygobe Dec 08 '20 at 11:35
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It may be related to a current user if you run php from another user. Run `whoami` from PHP and in the terminal. But if you run both as the same user, there should be something else. For example, `shell_exec` can be disabled. You may also run another function like `exec('which pdftohtml', $output, $result);` (there is a big chance it will be also disabled) – Fogus Dec 08 '20 at 11:40
Actually, if `shell_exec` is disabled, probably, you won't be able to run `pdftohtml` as well. Check `function_exists('shell_exec')`. Of course, you should see if it didn't exist when you ran `shell_exec` before, but maybe your script doesn't show errors and it was the end of your script. – Fogus Dec 08 '20 at 11:45
If I run other commands like `which which` it returns the path, doesn't return it for `pdftohtml`. If I run the script to transform pdf files to html it works, so there is a working `pdftohtml` installed on the server. interesting.... – Szekelygobe Dec 08 '20 at 11:45
You may also check (debug) how your script runs `pdftohtml` to transform what you need. There you should find the correct way of running it. And then use the same to check. E.g. replace all the params of `pdftohtml` to `-v`. Or something similar – Fogus Dec 08 '20 at 11:47

Check if PDFTOHTML is installed on server

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