Perl substring FAQ: How do I extract a substring from a string?
Solution: Use the Perl substr function. The general substr syntax looks like this:
$my_substring = substr($full_string, $start_pos, $length);
Perl substring example (substr)
A more specific Perl substring example is shown in the following code, where I extract the
$lastname strings from the
$name = "alvin alexander"; $firstname = substr($name, 0, 5); $lastname = substr($name, 6, 9); print "first name: $firstname\n"; print "last name: $lastname\n";
If I take that code and place it in a file named
sub.pl, and then run it through the Perl interpreter, the output looks like this:
$ perl sub.pl first name: alvin last name: alexander
Perl substr - things to remember
The most important thing to remember is that the starting position is a zero-based number, so when I grabbed my first name from the string, like this:
$firstname = substr($name, 0, 5);
I used the number
0 as my starting position, as that represents the first character in the string.