--first_program.pl-- use strict; #use warnings; open (F, "<", "test.out"); while(){ print "$_"; } -- second program-- use strict; use warnings; my $name = ''; my @id_list; open (STDIN,"perl first_program.pl|") || die "$!"; open (OUT, ">", "out.txt") || die "$!"; # chomp std line in while(my $line_in =){ chomp($line_in); my @line_array = split('\t',$line_in); my @subline_array = split('\|', $line_array[1]); @id_list = () unless ($name eq $line_array[0]); $name = $line_array[0] unless ($name eq $line_array[0]); next if (grep{$_ == $subline_array[3]}@id_list); push(@id_list,$subline_array[3]); print OUT "$line_in\n"; } #### mmenr hh|gg|kk|3445|uu|zzz 234 wwe we qw 233