my ( $from, $srvrip ) = $remainder =~ m/<=\s*(\S+)[^[]+\[([^\]]+);
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If that's not just a cut-and-paste tyop (no terminating / for the m//), then your Perl implementation is seriously deficient since Perl has had the  \S character class (complement of \s) since 4.? at least (to the best of my recollection).

Update: I just noticed that the Solaris Perl 5.8.4 compiler is complaining about both  \S and  \s (big-S and little-s) classes. Well, the comment still applies.