[[!meta title="How do I debug my scripts?"]]
Unfortunately, scripts.mit.edu does not support per-user error logs
(yet!), so debugging a recalcitrant CGI script may be a little
difficult. While the Scripts team hopes to add error logging in the
near future, here are some immediate ways you can convince your
scripts to give you more information:

-   You can view error logs in real time using the ‘logview’
    command on a Scripts server. Note that you need to be SSH’ed into
    the server that is serving your website, and not necessarily
    scripts.mit.edu server. You can determine what server you are being
    load-balanced to by checking the bottom of http://scripts.mit.edu
    and looking for “You are currently connected to XXX.mit.edu”
    server. This will not display all errors: in particular, if an
    error message spans multiple lines, you will only see the first
    line, and error messages with no data associated with your locker
    will also be hidden.

-   If you have a PHP script that is failing with no error output,
    you likely have error reporting turned off. Open or create a
    php.ini file in the same directory as the script, and in it ensure
    that “display\_errors = on” and “error\_reporting = E\_ALL \^
    E\_NOTICE”. This will cause errors to be displayed on the web
    page.

-   If you have some script that you know is writing information to
    stderr that you want to see, you can often run it directly from the
    command line via SSH to scripts and see if it outputs anything
    interesting. Nota bene: the configuration of the command line may
    be subtly different than that invoked from the web, for example,
    php from the command line will not load a php.ini file in the
    directory; you’ll need to manually add it with -c

-   If your FastCGI script is not working and you’re getting error
    messages like:
        [Fri Oct 29 20:31:04 2010] [notice] mod_fcgid: process
          /afs/athena.mit.edu/contrib/scripts/web_scripts/index.fcgi(15116)
          exit(communication error), terminated by calling exit(), return code: 121

    this probably means your index.fcgi is lacking the executable bit.
    You can set it using `chmod a+x index.fcgi`.