Code: perl -i~ -nle ' BEGIN { %seen = ('tito-k.abcd.com' => 1, 'reta-k.abcd.com' => 1); } print unless $seen{$_}++; END { print "
pppp.abcd.com" unless $seen{"pppp.abcd.com"}' file [/quote] Hi, Its giving error. String found where operator expected at code line 1, near "nle ' BEGIN { %seen = ('" (Do you need to predeclare nle?) Bareword found where ...