Hello GrandFather, Thank you so much for your great help! Really appreciate your great help! Best, Yue

#!/usr/bin/perl
use warnings;
use strict;


open my $TAB01, '<', 'tmp01_quick' or die "Cannot open 'donor_82_01.cs
+v' because: $!";
open my $TAB02, '<', 'tmp02_quick' or die "Cannot open 'tmp12' because
+: $!";
open my $OUT, '>', 'tmp12_01_QUICK' or die "Cannot open 'tmp12_01' bec
+ause: $!";


my $tmp11_QUICK = '';
my %peptides;

#open my $TAB01, '<', \$tmp01_quick;

while (<$TAB01>) {
    chomp;
    
    my ($peptide, $protein) = split /\t+/;
    next if $peptide !~ /\d/;
    
    #$peptides{$peptide} //= [];
    push @{$peptides{$peptide}}, $protein;
}

#open my $TAB02, '<', \$tmp02_quick;
#open my $OUT, '>', \$tmp11_QUICK;

while (<$TAB02>) {
    chomp;
    
    my ($peptide, $spectrum, $sequence) = split /\t+/;
    next if $peptide !~ /\d/;
    
    print $OUT "$peptide\t$_\t$spectrum\t$sequence\n" for @{$peptides{
+$peptide}};
}

close $OUT;

print $tmp11_QUICK;
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