You could also use the range (flip-flop) operator. The sample below will print lines from the line which starts with "head" (^ anchors to the start) to the one which ends with "tail" (\s*$ allows some white space after tail.)

#!/usr/bin/perl

use strict;
use warnings;

while(<DATA>)
{
  print if /^head/i../tail\s*$/i;
}


__DATA__
HEAD gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla tail gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus head bla bla gugus gugus tail
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus head
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
tail gugus gugus
[download]

Output

HEAD gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla tail gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus gugus bla bla gugus gugus
bla bla gugus head bla bla gugus gugus tail
[download]

Update
If you have the camel book, you can find a discussion on this starting on page 90 (2nd Edition).

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.