perl script for merging .tex files and BibTeX output into single .tex file

mergetex.pl

#!/usr/bin/perl

# mergetex.pl
#
# Script for merging tex files into a single monolithic file.  This
# script should make it easy to generate an ArXiV-friendly single
# .tex file from a paper that is broken into subfiles using LaTeX's
# \input{} command.
#
# USAGE:
#     ./mergetex.pl  [input]  [output]
#     ./mergetex.pl  mypaper.tex  mypaperMerged.tex
#
# mergetex takes two arguments, the [input] file and the [output]
# file into which the merged files should go.  It recursively
# searches [input] and adds any file given by uncommented \input{}
# commands.
#
# v0.1 by Anand Sarwate (asarwate@alum.mit.edu) with tips from Erin Rhode.
# Modified by Manu Sridharan to also merge in BibTeX output.

use IO::File;

if ( scalar(@ARGV) != 2) {
   die "Syntax Error : use 'mergetex.pl [input] [output]'"
}
$infile = shift;
$outfile = shift;
print "Generating tex file from $infile and storing in $outfile.\n";
my $outputfh = new IO::File($outfile, "w") or die "Could not open $outfile: $!\n";
my $inputfh = new IO::File($infile, "r") or die "Could not open $infile: $!\n";
parsetex($inputfh,$infile);
$outputfh->close();

sub parsetex {
  my $fh = shift;
  my $file = shift;
  print "Found $file.  Merging into $outfile.\n";
  while (<$fh>) {
    # strip out comments
    $decom = $_;
    $decom =~ s/^\%.*$/\%/;
    $decom =~ s/([^\\])\%.*$/\1\%/g;
    # search for lines with "\input{}"
    if ($decom =~ /\\input{(.*?)}/) {
      #get new file name
      if ($1 =~ /.tex/) {
        my $newfile = $1;
      } else {
	$newfile = $1 . ".tex";
      }
      # recurse to input new file
      my $newfh = new IO::File($newfile, "r") or die "Could not open $infile: $!\n";
      parsetex($newfh,$newfile);
    } elsif ($decom =~ /\\bibliography{(.*?)}/) {
        # try to input the .bbl file; if it doesn't exist, just copy
        # the file
        my $bblfile = $infile;
        $bblfile =~ s/\.tex/.bbl/g;
        my $bblfh;
        if ($bblfh = new IO::File($bblfile, "r")) {
            parsetex($bblfh,$bblfile);
        } else {
            $outputfh->print($decom);
        }
    }
    else {
      $outputfh->print($decom);
    }
  }
  $fh->close();
}