Also, you can use \Q...\E to quote otherwise regex-meaningful characters. E.g. 

$p = "horraen=sumsel[13])\n";  # no backslashes required
$m = qr/\Qsumsel[13]\E/;  # actually in this case qr/\Qsumsel[13]/ is 
+enough
print $p;
if ( $p =~ /$m\)/ ) { print "yeah!\n"; }
else { print "why isn't it matching?\n"; }
__END__
horraen=sumsel[13])
yeah!

[download]
See also quotemeta.

the lowliest monk

In reply to Re: regexp matching with "\[" in the substring to be matched by tlm
in thread regexp matching with "\[" in the substring to be matched by ISAI student

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