use strict;
use warnings;

seek DATA, 0, 0;
print while <DATA>;

__DATA__
[download]

Prints:

use strict;
use warnings;

seek DATA, 0, 0;
print while <DATA>;

__DATA__
[download]

Update Note that you must have either __END__ or __DATA__ at the end of the script (you may have data following that if you wish - it will be printed too).

Another way to do it in Linux:

use strict;
use warnings;
system("cat $0");
[download]

If your on a Windows box, change cat to type, and consider adding quotation marks (for the likely case of a filename with spaces in it):

use strict;
use warnings;
system("type \"$0\"");
[download]

You can have spaces in filenames on Linux (and Unix) too. And using qq// would avoid all that ugly escaping.

system(qq(cat "$0"));
[download]

--
<http://dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg

and
system('cat', $0);
would need no quoting at all =)

update: actually only system(cat => $0); really needs no quotes... isn't that elegant?

or just:

open SRC, '<', $0 or die;
print for <SRC>;
close SRC;
[download]

/usr/bin/perl $@
cat $1
[download]

package foo;
use Filter::Simple;
FILTER {
  $_ .= "\n;print qq{\n===SOURCE CODE===\n$_};";
};
1;
[download]

use foo;
use strict;
use warnings;
print "hello world";
[download]

use Acme::Echo 'after', src_fmt=>"Source of just-executed code:\n%s";
use strict;
use warnings;
print "hello world\n";
[download]

hello world
Source of just-executed code:
use strict;
use warnings;
print "hello world\n";
[download]

But that only prints part of the source. :)

---

DWIM is Perl's answer to Gödel

well, yeah :) .. well, prints the enitre thing between the 'use Acme::Echo' statement and the end or a 'no use Acme::Echo' .. which could be handy .. and could turn on,off,on,off as desired..

And in lines mode you'll lose some whitespace ... though it provided a challenging Filter::Simple and PPI task -- you can see i had trouble recursing into compound statements .. it's on my project list to revist ;)

You have a file called 'hello_world.pl' with the content you have shown. On the command promt you type perl hello_world.pl and get the printed hello world as a return.

Now you would like to know how to get the text of the program printed out, instead of the program executed. This depends on your operating system. On Unix/Linux you type cat hello_world.pl and on Windows you type type hello_world.pl.

For how to do these things from perl, see the other answers.

For those wondering, a simple Google search reveals the following site:

http://www.cliff.biffle.org/esoterica/hq9plus.html

to which brother ysth was cryptically referring to. See also http://en.wikipedia.org/wiki/HQ9+.

Alex / talexb / Toronto

"Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds