It seems to me that you are asking for something as simple as this.

my @ss = (
    'A',
    'B',
    'C',
    'AB',
    'CA',
    'ABC',
    'xABCx',
    'BxCxAx',
);

for my $s (@ss) {
    if ($s =~ /A/ && $s =~ /B/ && $s =~ /C/) {
        print "$s\n";
    }
}

[download]

Which outputs:

ABC
xABCx
BxCxAx

[download]

EDIT: This response is only to the first part of the OP's question. That is:

...if you have the strings:

$a='ABCAAAABBBCCCCCAAABBBCCC';
$b='ASRGRTGRT89579843rrrrrr';

and you wanted to pick only the string that contains A, B and C (namely $a)...

In reply to Re: Match only certain characters? by jffry
in thread Match only certain characters? by Anonymous Monk

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