Re: Regex to check for very large negative numbers

You claim that the regex m/-\d+\d+\d+\d+\d+\d+\d+\d+\d+\d+\d+.*\..*/ “always matches” — but it doesn’t!

#! perl
use strict;
use warnings;

while (<DATA>)
{
    chomp;
    print "$_ is a match\n" if /-\d+\d+\d+\d+\d+\d+\d+\d+\d+\d+\d+.*\.
+.*/;
}

__DATA__
-523566.00
-0.0013
0.0045
-32742987982758110638106318307132432131.0000
[download]

Output:

21:30 >perl 543_SoPW.pl
-32742987982758110638106318307132432131.0000 is a match

21:39 >
[download]

Perhaps the problem lies in how you’re testing the regex against the data?

Incidentally, you can write an equivalent regex more compactly using the {n,} quantifier, which will “Match at least n times” (see “Quantifiers” in Regular Expressions):

/-\d{11,}.*\..*/
[download]

as per the answers above by moritz and BillKSmith.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

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Re^2: Regex to check for very large negative numbers
by cspctec (Sexton) on Feb 26, 2013 at 12:55 UTC

Thanks for the help everyone. I think I have enough information to find a solution.

[reply]


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