splitbycol.pl

splitbycol.pl

#!/usr/bin/perl

# Thursday, March 10, 2011
# Stephen D. Turner

chomp(my $pwd = `pwd`);
my $help = "\nUsage: $0 <file to split> <# columns in each split>\n\n";
die $help if @ARGV!=2;

#sub trim($);

$infile = $ARGV[0];
chomp($ncol = `head -n 1 $infile | wc -w`);
$ncol = trim($ncol);

$start=1;
$inc = $ARGV[1];
$end = $start+$inc-1;

die "\nSplit size >= number of columns\n\n" if $inc>=$ncol;

for($i=1 ; $i<$ncol/$inc +1 ; $i++) {
	if ($end>$ncol) {$end=$ncol;}
	`cut -f $start-$end $infile > $infile.$i.txt`;
	$start += $inc;
	$end += $inc;
}

# function to trim leading and trailing whitespace
sub trim($)
{
	my $string = shift;
	$string =~ s/^\s+//;
	$string =~ s/\s+$//;
	return $string;
}