@files = sort { my ($ad) = ( $a =~ /fwlog\.(\d+)\w+/ ); my ($bd) = ( $b =~ /fwlog\.(\d+)\w+/ ); $ad <=> $bd } @files; print join "\n", @files; OUTPUT: fwlog.1Mar2005.gz fwlog.2Mar2005.gz fwlog.3Mar2005.gz fwlog.4Mar2005.gz fwlog.5Mar2005.gz fwlog.6Mar2005.gz fwlog.7Mar2005.gz fwlog.8Mar2005.gz fwlog.9Mar2005.gz fwlog.14Mar2005.gz fwlog.15Mar2005.gz fwlog.16Mar2005.gz fwlog.17Mar2005.gz fwlog.18Mar2005.gz fwlog.19Mar2005.gz fwlog.20Mar2005.gz fwlog.21Mar2005.gz #### fwlogfwlog.14Mar2005.gz.Mar2005 fwlogfwlog.15Mar2005.gz.Mar2005 fwlogfwlog.16Mar2005.gz.Mar2005 fwlogfwlog.17Mar2005.gz.Mar2005 fwlogfwlog.18Mar2005.gz.Mar2005 fwlogfwlog.19Mar2005.gz.Mar2005 fwlogfwlog.1Mar2005.gz.Mar2005 fwlogfwlog.20Mar2005.gz.Mar2005 fwlogfwlog.21Mar2005.gz.Mar2005 fwlogfwlog.2Mar2005.gz.Mar2005 fwlogfwlog.3Mar2005.gz.Mar2005 fwlogfwlog.4Mar2005.gz.Mar2005 fwlogfwlog.5Mar2005.gz.Mar2005 fwlogfwlog.6Mar2005.gz.Mar2005 fwlogfwlog.7Mar2005.gz.Mar2005 fwlogfwlog.8Mar2005.gz.Mar2005 fwlogfwlog.9Mar2005.gz.Mar2005 #### fwlog.9Mar2005.gz fwlog.8Mar2005.gz fwlog.7Mar2005.gz fwlog.6Mar2005.gz fwlog.5Mar2005.gz fwlog.4Mar2005.gz fwlog.3Mar2005.gz fwlog.2Mar2005.gz fwlog.21Mar2005.gz fwlog.20Mar2005.gz fwlog.1Mar2005.gz fwlog.19Mar2005.gz fwlog.18Mar2005.gz fwlog.17Mar2005.gz fwlog.16Mar2005.gz fwlog.15Mar2005.gz fwlog.14Mar2005.gz