Perl – If string contains text?

If you just need to search for one string within another, use the index function (or rindex if you want to start scanning from the end of the string):

if (index($string, $substring) != -1) {
   print "'$string' contains '$substring'\n";
}

To search a string for a pattern match, use the match operator m//:

if ($string =~ m/pattern/) {  # the initial m is optional if "/" is the delimiter
    print "'$string' matches the pattern\n";       
}