Transpose a CSV array

ArrayTranspose.pl

#! /usr/bin/perl
# transposes input.csv to output.csv. 
# 
# eg: input.csv: 
#   "id","1","2"
#   "A1","a","b"
#
# output.csv will be
# "id","A1"
# "1","a"
# "2","b"
#

### do not edit below this line ###
use strict;
my $infile = 'input.csv';
my $outfile = 'output.csv';

open (F, $infile) || die ("Could not open $infile!");

my @data = ();
my ($line, $i, $j,$check);
while ($line = <F>) {
  push(@data,[split("\",\"", $line)]);
}
print "got ".scalar(@data)." lines from $infile, with ".scalar($#{$data[0]})." items in first line\n";
close (F);

(scalar(@data)>0) || die ("$infile is empty");

# quick check to verify no splitting was done in actual data, i.e. all lines have same numbers of data
# and remove starting and trailing " from each line
$check = 0;
for $i ( 0 .. $#data ) { 
  $check = $check + scalar($#{$data[$i]});
  $data[$i][0] = substr($data[$i][0],1);
  chop($data[$i][scalar($#{$data[$i]})-1]);
}
$check = $check / scalar(@data);
print "average line length: $check\n";
($check == scalar($#{$data[0]})) || die ("please correct input.csv to ensure the following characters do not appear in the data: ".'","'."\n");


open(OUT, "> $outfile") || die "$outfile cannot be opened.";

for $j ( 0 .. $#{$data[0]} ) {
	for $i ( 0 .. $#data ) {
		print OUT "\"$data[$i][$j]\"";
		if ($i<($#data)) {print OUT ",";}
	}	
	print OUT "\n";
}
close (OUT);