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ankit
Asked: 2011-01-25 19:13:33 +0800 CST

Setup PHP Permission under Apache

  • 772

what i am trying to acomplish is to have a php page execute a shell command and display the output on the web page.

the code for the page is something along the lines of 

<?php
echo shell_exec('ls -l /code');
?>

when i load up this page all i see is blank. yet when i execute it from the command line i see the command being executed and the output printed.

I am sure its something to do with the permissions and i am hoping someone can point me the right way.

this is what I see in the httpd log file

ls: cannot access /gateway_code: Permission denied
ls: cannot access /gateway_code: Permission denied

BTW the directory /code is set to "Read only" for the user "apache"

thanks! -ankit

linux php file-permissions

3 Answers

  1. Check your base directory restriction. Php doesn't have permission to access /bin/ls. Instead of adding /bin directory to the base directory restriction list copy /bin/ls over to the folder /code.

    If you really have to do this.

    • 0

  2. BTW the directory /code is set to "Read only" for the user "apache"

    That's your interpretation of the way the permissions have been set - it would have been a lot more useful if you'd told us what the permissions actually are.

    I suspect the directory is not executable by the apache uid. Or there maybe MAC/ACL issues in play here - but you've provided no details of which Linux distribution this is, nor how the permissions are set up.

    • 0

  3. The first thing to do is make PHP give you a better answer than just a blank page. You can redirect stderr to stdout using 2>&1 such that the error message will be printed with echo.

    <?php
echo shell_exec('ls -l /code 2>&1');
?>

    Next, make sure that whatever process is running your php script (ie. apache) has execute permissions on the directory you're trying to list. If you don't mind being heavy-handed, you can easily determine whether permissions are the problem by just giving rwx access to everybody.

    > chmod 777 code

    And finally, make sure that you're specifying the right path. In your question you say that you're trying to list the contents of /code -- is it really your intention to be listing a root level directory? If the code folder is in the same directory as your script, you might have better luck with a relative path.

    echo shell_exec('ls -l ./code 2>&1');
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