extools/merge_lines.pl

   1 #!/usr/bin/perl -w
   2 use strict;
   3
   4 if (scalar @ARGV < 2) {
   5   die "Usage: $0 file1.txt file2.txt ...\n\n  Concatenate the nth line of each input file. All files\n  must be the same length.\n\n";
   6 }
   7
   8 my @fhs=();
   9 for my $file (@ARGV) {
  10   my $fh;
  11   open $fh, "<$file" or die "Can't read $file: $!\n";
  12   push @fhs, $fh;
  13 }
  14
  15 my $first = shift @fhs;
  16
  17 while(my $x = <$first>) {
  18   my $ind = 0;
  19   chomp $x;
  20   my @fields = ($x);
  21   for my $fh (@fhs) {
  22     $ind++;
  23     $x = <$fh>;
  24     die "ERROR: Mismatched number of lines: $ARGV[$ind]\n" unless $x;
  25     chomp $x;
  26     push @fields, $x;
  27   }
  28   print join ' ||| ', @fields;
  29   print "\n";
  30 }
  31 my $ind = 0;
  32 for my $fh (@fhs) {
  33   $ind++;
  34   my $x=<$fh>;
  35   die "ERROR: $ARGV[$ind] has extra lines!\n" if $x;
  36 }
  37
  38 exit 0;
  39
  40 for my $fh (@fhs) {
  41   close $fh;
  42 }
  43