#  $start = index($string, $look_for);

#  If you intend to search a string for multiple occurrences of the look-for substring, you can use the optional start position:

#  $start = index($string, $look_for, $start_position);


#!/usr/bin/perl -w

# Look for a substring with index.

$look_for = "then";

$start = index("First A, then B", $look_for);

print "$look_for starts at $start\n";