Hi Monks,
I wanted your help to fix a couple of pattern matching regex that I have. My script: 
#!/usr/bin/perl
use strict;
use warnings;

my $s='IIIIIIIIIIIIIIIIIIIIIIIIIIOOOOOSSSSS';

if (0 == $s =~ tr/[IOSM]//c) {
    print "case1\n";
}

elsif (0 == $s =~ tr/[IOS]//c) {
    print "case2\n";
}

[download]

Can you tell me why it prints case1 although my string does not have M inside?

In reply to Pattern matching regex problem by Anonymous Monk

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