c:\@Work\Perl\monks>perl -wMstrict -le
"for my $string (qw(
50.10-d557_5 50.10-d557_8 50.10-d557_20 50.10-d557_123
)) {
my ($value) = $string =~ m{ _ (\d+) \z }xms;
print qq{'$string' -> '$value'};
}
"
'50.10-d557_5' -> '5'
'50.10-d557_8' -> '8'
'50.10-d557_20' -> '20'
'50.10-d557_123' -> '123'
Please see
perlre,
perlretut, and
perlrequick.
(Update: Also see articles in the Tutorials -> Pattern Matching, Regular Expressions, and Parsing section.)
Update: For completeness, here's code showing capture and use of matching/parsing success status, and also some edge-case and failing parse examples. Data::Dumper::Dumper(), which is core, can be used instead of non-core Data::Dump::dd().
c:\@Work\Perl\monks>perl -wMstrict -e
"use Data::Dump qw(dd);
;;
for my $string (qw(
50.10-d557_5 50.10-d557_8 50.10-d557_20 50.10-d557_123
_5 ___6 9_99_999_321
999_x 999_7x 999_ 999 _
)) {
my $got_value = my ($value) = $string =~ m{ _ (\d+) \z }xms;
dd $string, $value, $got_value;
if ($got_value) {
print qq{'$string' -> '$value' \n\n};
}
else {
print qq{'$string' parse failed \n\n};
}
}
"
("50.10-d557_5", 5, 1)
'50.10-d557_5' -> '5'
("50.10-d557_8", 8, 1)
'50.10-d557_8' -> '8'
("50.10-d557_20", 20, 1)
'50.10-d557_20' -> '20'
("50.10-d557_123", 123, 1)
'50.10-d557_123' -> '123'
("_5", 5, 1)
'_5' -> '5'
("___6", 6, 1)
'___6' -> '6'
("9_99_999_321", 321, 1)
'9_99_999_321' -> '321'
("999_x", undef, 0)
'999_x' parse failed
("999_7x", undef, 0)
'999_7x' parse failed
("999_", undef, 0)
'999_' parse failed
(999, undef, 0)
'999' parse failed
("_", undef, 0)
'_' parse failed
Give a man a fish: <%-{-{-{-<
