csv2tab

#!/usr/bin/perl
use strict;
use Getopt::Std;
use FindBin;use lib $FindBin::Bin;

my $usage = q/Usage:
  csv2tab [-n][-H] input.csv
  Converts a csv to a tab delimited output, removing double quotes 
  around every field.
  
  Options:
   -n : disable header
   -H : show only the header
/;
umask 0002;
getopts('nHo:') || die($usage."\n");
my $outfile=$Getopt::Std::opt_o;
my ($nohdr, $hdronly)=($Getopt::Std::opt_n, $Getopt::Std::opt_H);
if ($outfile) {
  open(OUTF, '>'.$outfile) || die("Error creating output file $outfile\n");
  select(OUTF);
  }
# --
my $ln=0;
while(<>) {
   $ln++;
   next if ($ln==1 && $nohdr);
   my $re = qr/,(?=(?:[^"]*"[^"]*")*(?![^"]*"))/;
   print join "\t", map { s/(?<!\\)"//gr =~ s/\\"/"/gr } split $re;
   exit if ($hdronly);
}


# --
if ($outfile) {
 select(STDOUT);
 close(OUTF);
 }

#************ Subroutines **************