Hello mavericknik,

I think you’re looking for something like this:

#! perl
use strict;
use warnings;

while (<DATA>)
{
    print "$1.$2\n" if m{ ^ \s* Pin: \s* ([^.]*?) \. (\S*) (?: \s+ out
+)? $ }x;
}

__DATA__
  Pin:  U343.IN1  in
  Pin:  U713.INP  out
  Pin:  U714.QN
[download]

Output:

18:14 >perl 1318_SoPW.pl
U713.INP
U714.QN

18:14 >
[download]

Update: Some notes:

• The /x modifier makes the regex easier to read.
• The character classes \s and \S represent whitespace and non-whitespace characters, respectively.
• There is no need to escape a . inside a character class.
• The *? quantifier is non-greedy, so if there’s a second . character in the string the literal \. will still match the first one.
• The (?: ...)? construct matches the contents optionally, and without capturing.

Hope that helps,