If the file is small enough that you don't mind a little slurping, here's an easy way using grep. (This assumes that you want to print the entire line where the matches are found): 

my @list = grep /\btest\b/, <DATA>;
chomp @list;
print "$_\n" foreach @list;

__DATA__
This is only a test.
Here's a line that doesn't contain the trigger text.
This line contains test and test again.
Now you see it, now you don't.
Testing one two three.
Test or not to test?

[download]

This passes a filehandle to grep, along with a simple regexp that tells it to find only those lines that contain the word "test" (rejecting words like 'testing').

For matches across multiple lines you have to set the $/ special variable to paragraph or slurp mode and use an /s modifier on your regexp.

In reply to Re: how can i search a text file for a string and print every occurence of that string by davido
in thread how can i search a text file for a string and print every occurence of that string by natty-dread

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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! —
  • 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:
    & &amp;
    < &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.