How can I find a 'Document contains no data' problem?

[Anonymous Monk]

I have a html page which refers to a cgi script written in perl. However, when I click on the 'Send' button on this page, I get the message 'Document contained no data'. What could be wrong?

I have already checked the path for perl in the cgi script.

Also the path for the perl cgi script in the html page also seems to be right?

What other things can I check?

Any help would be deeply appreciated.

Originally posted as a Categorized Question.

[extremely]

Document contains no data is a pretty clear indicator that your program exited early. Like other have said, check your error logs, add the lovely use CGI::CARP qw(fatalsToBrowser); to hopefully get SOME data to the browser.

Also, if it's a basic perl script cgi try perl -cw filename.cgi and see if it complains about a simple error that might bomb it out.

I had this happen once with a 45kb script with scads of modules. I had -w and use strict; and CGI and Carp and all that jazz going, no errors in the log, no compile errors, nothin. After hours, literally, I noticed that I had absentmindedly put an exit(0); where a much more reasonable return(0); should have been. =) It happens...

[steveAZ98]

First check your permissions for the script, make sure it's executable. ie chmod 755 scriptname in the unix world.

Then check that your script is sending back the content type ie. Content-type: text/html\n\n

Then check that your webserver is configured for the directory of where your script lives. ie. if your webserver is configured for cgi scripts in /cgi-bin and your calling /bin/script

If all those are correct, check the error logs of that website. Any errors in opening files, file permissions etc. should be there. Maybe you want to check this first as it will give you a better idea of where to start.

HTH

Also, try using use CGI::Carp qw/fatalstoBrowser/ to get any error messages to appear in the browser window.
Contributed by davorg -- Q&AEditors

[rgl]

Another common problem is the mismatch in the left and right brackets! unequal no. of ( & ) or { & }. rgl

Originally posted as a Categorized Answer.

[cei]

One that kills me sometimes when I'm not paying attention: make sure your script is using line breaks that match the system your server is running. I often write my perl in BBEdit on my Mac, but I have to save with DOS or UNIX linebreaks for them to run properly on a server. When I don't the "Document contained no data" is the error it gives me.

[Anonymous Monk]

I had to have print "Status: 302\n"; before the Location: This was the only solution.