Re: String Match Use of $1 Uninitialized

[kennethk]

The issue is that you are not capturing any text from your regular expression in the second case, so that sets all the captured groups to undef. Which strings are captured is controlled by parentheses in your regular expression - see perlre, perlretut. For example, of you wanted to capture the letters 'AIR' from your string into the $1 buffer, you might use:

my $line = "PID: AIR-LAP1142N-A-K9   ,  VID: V01,  SN: FTX1332SC15";
$line =~ m/(AIR)-LAP1142N-A-K9/;
print $1 . "\n";

[spickles]

Gentlemen:

Makes a lot of sense now. Thanks for that. The docs I was reading weren't from perlretut and didn't make the function of grouping apparent.

Regards,
Scott

[ikegami]

Putting stuff in $1 is called capturing. While parens also do grouping, it's usually done using (?: ... ). For example, /abc(?:def|ghi)/.