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).

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.