use warnings;
use strict;

my $nLines = 0;
while (<DATA>) {
    $nLines = 5 if /kjkjkjkj/;
    print if $nLines-- > 0;
}
__DATA__
1asdfasdf
2asdfasdf
3kjkjkjkjkj
4asdfasdf
5asdfasdf
6asdfasdf
7asdfasdf
8asdfasdf
9asdfasdf
10asdfasdf