Many ways... one is 
while(<DATA>) {
    chomp;
    print "$_ => @_\n" if @_= /(abc|xyz)(?=(?:...)*$)/g;
}
__DATA__
abcmmmnnn
mmmxyznnn
mabcmxyzm
xyzfooabc
__END__
abcmmmnnn => abc
mmmxyznnn => xyz
xyzfooabc => xyz abc

[download]

--shmem 

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

In reply to Re: cool regular expression needed for matching in columns by shmem
in thread cool regular expression needed for matching in columns by Ben Win Lue

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