Premature end of script headers

zitic has asked for the wisdom of the Perl Monks concerning the following question:

Hello!

#!/usr/bin/perl

use strict;
use warnings;

print "Content-type: text/html\n\n";

print '<html><head></head><body>'."\n";
print 'Some content here'."\n";
print '</body></html>'."\n";
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I just can't understand what exactly is wrong with this script. Browser receives message 'Internal server error' and apache error log has line 'Premature end of script headers'.

I understand that this error could be logical if I had missed following line:

print "Content-type: text/html\n\n";
[download]

So I'm really confused.

Comment on Premature end of script headers Select or Download Code

Replies are listed 'Best First'.
Re: Premature end of script headers by marto (Cardinal) on May 11, 2010 at 08:47 UTC
In addition to what Corion said, consider using the CGI module. See Ovid's CGI Course - Resurrected and Updated! for further details.	[reply]
Re: Premature end of script headers by Corion (Patriarch) on May 11, 2010 at 08:45 UTC
HTTP headers are delimited by `\r\n`, not `\n`.	[reply] [d/l] [select]
Re^2: Premature end of script headers by JavaFan (Canon) on May 11, 2010 at 13:05 UTC
Yes, and? The script isn't talking HTTP. HTTP is the protocol between the server and the browser. This is conversation between the server and a program. They are using the CGI protocol. I'm not aware of any server that doesn't know how to deal with "\n" being used instead of "\r\n" in the CGI protocol.	[reply]
Re: Premature end of script headers by Skriptke (Acolyte) on May 11, 2010 at 12:11 UTC
Many times the error "Premature end of script headers" occur not because, our heads are bad, but because a previous error written "\n\n" to the output before our "\n\n". Checks, file permissions, missing libraries, server config, etc ...	[reply]
Re^2: Premature end of script headers by moritz (Cardinal) on May 11, 2010 at 12:14 UTC
I'd like to add that it's often interesting to just start the script from the command line - often it's obvious from the output what the problem is. (Yes, you can run a CGI script without CGI. No, it won't kill any kittens.)	[reply]
Re^3: Premature end of script headers by Skriptke (Acolyte) on May 11, 2010 at 12:23 UTC
you're right, but in this case I vote for a bug in file permissions, without running the script on any site :-)	[reply]
Re: Premature end of script headers by Anonymous Monk on May 11, 2010 at 13:12 UTC
CGI Help Guide has a list of common errors to check	[reply]
Re: Premature end of script headers by zitic (Initiate) on May 11, 2010 at 14:00 UTC
Thank you all for your answers I finally figured out where the error really was. Turns out the script file had wrong extension. All I needed to do was to rename my_file.pl to my_file.cgi -- and it worked just fine!	[reply]
Re^2: Premature end of script headers by ww (Archbishop) on May 11, 2010 at 16:17 UTC
If so, that's an issue with how Apache is configured; not an issue with Perl itself.	[reply]