Re: Regex pattern that fails when string contains a certain pattern

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1178340

use strict;
use warnings;

while(<DATA>)
  {
  print /^(?!.*_\d)/ ? "    matched $_" : "not matched $_";
  }

__DATA__
aa1.2
aa1_bb2
aa1_2
aa1_2bb
1aa
[download]

Your last test case '1aa' has no underscore and therefor by your rule should match.

Edit after your edit (I think)

/^(?!.*[-_]\d)/
[download]

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Re^2: Regex pattern that fails when string contains a certain pattern by hoppfrosch (Scribe) on Dec 22, 2016 at 09:47 UTC
Thanks!!! You're right: my specification was incomplete. Extended specification: Strings starting with a number should not be matched as well	[reply]
Re^3: Regex pattern that fails when string contains a certain pattern by tybalt89 (Monsignor) on Dec 22, 2016 at 09:51 UTC
`#!/usr/bin/perl # http://perlmonks.org/?node_id=1178340 use strict; use warnings; while(<DATA>) { print /^(?!.*(?:-\|_\|^)\d)/ ? " matched $_" : "not matched $_"; } __DATA__ aa1.2 aa1_bb2 aa1_2 aa1_2bb 1aa` [download]	[reply] [d/l]