exec() and phantomjs issue with absolute paths

Question

I'm using phantomJS for the purposes of programmatically taking screenshots of a webpage. My webserver runs on Linux 64 bit.

The Scenario

My test.php file

exec('./phantomjs --version', $o, $e);
print_r($o);
echo $e;

I open test.php in a browser. The out put I get is:

1.9.1 // version number
0 // exit code

This proves that I can run commands through exec() and phantomJS is working perfectly.

The Issue

Now when I replace the above code with:

exec('./phantomjs http://mywebsite.com/test.js', $o, $e);
print_r($o);
echo $e;

The output is:

Array ( ) // empty output
139 // exit code which on investigating turned out to be segmentation fault

I also tried:

exec('./phantomjs ./test.js', $o, $e); // since phantomjs and test.js are in same folder

but the result was the same (segfault)

test.js code:

var page = require('webpage').create();
var url = 'http://www.rediff.com/';
page.open(url, function (status) {
    phantom.exit();
});

This makes me believe that using the full path as the second argument of phantomJS is causing it to crash. Thus, the things that I'm wondering are:

Am I right in my assumption?
Or is it because of some restriction on my webserver which is blocking exec() from accessing the .js file through absolute URL?

I'd recommend using the full path both to phantomjs and the script you want to run, e.g. `/usr/local/bin/phantomjs /some/directory/test.js` — Niklas Lindblad, Sep 07 '13 at 14:38
Q1. Are you using SELinux? (e.g. it appears to be used by default with Centos) Q2. Does it work if you run php-cgi, instead of running it as a PHP module? — Darren Cook, Oct 03 '13 at 11:44

score 3 · Answer 1 · answered Feb 20 '14 at 17:42

3

After a lot of searching and testing I got it to work with following additions:

//throws a lot of errors because searching some libraries
$cmd = 'unset DYLD_LIBRARY_PATH ;';
$cmd.= ' /abs/path/to/phantomjs';
$cmd.= ' /abs/path/to/script.js';

//set environment variable to node source
putenv('PATH=/abs/path/to/node/bin/');

//now exec the cmd and pipe the errors to stdout
exec($cmd.' 2>&1', $output);

//and output the results
print_r($output);

I'm not the best server admin, so I can not explain everything in detail, but the lines above generate an pdf. Yeah.

answered Feb 20 '14 at 17:42

paul

488
5
16

1

unsetting DYLD_LIBRARY_PATH worked for me too. If anyone knows WHY, i'm open for some explaining. But thanks for this! – Henrik Peinar Mar 10 '14 at 16:23
This was the only way I could get my project to run locally on OSX Mavericks (using MAMP). When running the same project remotely on an Ubuntu server, I didn't need any of this sorcery. – lewsid Oct 01 '14 at 20:38
This was also the solution for me on OSX Mavericks with MAMP. Interestingly it worked on Yosemite without unsetting DYLD_LIBRARY_PATH. Interested in the reasoning if anybody knows. – antriver Mar 21 '15 at 21:27

score 1 · Answer 2 · edited May 23 '17 at 11:53

I had a similar issue. PHP + PhantomJS Rasterize I found that phantomjs does not like running from an apache process. Try running your exec command from the command line:

php -r "exec('./phantomjs http://mywebsite.com/test.js', $o, $e); print_r($o); echo $e;"

If this works you have a few options:

1.) Some have suggested modifying sudoers to give no password sudo permissions for apache user to phantomjs binary

2.) Do like I did and run your script as a cron.

score 0 · Answer 3 · answered Oct 04 '13 at 18:42

0

Try to place test.js in folder where test.php located (when calling exec('./phantomjs ./test.js', $o, $e);) or use full path.

answered Oct 04 '13 at 18:42

Mikhail Gerasimov

36,989
16
116
159

As I pointed out in my post test.js and test.php are in the same folder already. Also I'm facing issues when I'm using full path. – 403 Forbidden Oct 24 '13 at 11:45

score 0 · Answer 4 · answered Dec 04 '15 at 02:50

I found the issue to be with selinux (which is now disabled by default on all production server builds as standard).

in file /etc/selinux/config find line containing:

SELINUX=

and change it to this:

SELINUX=disabled

run command (to take immediate effect without reboot)

/usr/sbin/setenforce 0