use strict;
use warnings;

my @all_lines = <DATA>;

# get the lines that match the word 'number'
my @lines = grep /number/, @all_lines;

print "Lines that matched\n";
print for @lines;

# get and highlight the lines that match the word 'number'
my @bold = map { $_ =~ /number/ and s/number/<b>number<\/b>/g ? $_ : (
+); } @all_lines;

print "\nHighlighted word\n";
print for @bold;

__DATA__
number....................
.....................
......number..............
.........................
..................number
[download]

outputs:

Lines that matched
number....................
......number..............
..................number

Highlighted word
<b>number</b>....................
......<b>number</b>..............
..................<b>number</b>
[download]