Split delimited file into smaller files by column

Question

I'm familiar with the split command in linux. If I have a file that's 100 lines long,

split -l 5 myfile.txt

...will split myfile.txt into 20 files, each having 5 lines, and will write them to file.

My question is, I want to do this by column. Given a file with 100 columns, tab delimited, is there a similar command to split this file into 20 smaller files, each having 5 columns and all the rows?

I'm aware of how to use cut, but I'm hoping there's a simple UNIX command I've never heard of that will accomplish this without wrapping cut with perl or something.

Thanks in advance.

Answer 1

#!/bin/bash

(($# == 2)) || { echo -e "\nUsage: $0 <file to split> <# columns in each split>\n\n"; exit; }

infile="$1"

inc=$2
ncol=$(awk 'NR==1{print NF}' "$infile")

((inc < ncol)) || { echo -e "\nSplit size >= number of columns\n\n"; exit; }

for((i=0, start=1, end=$inc; i < ncol/inc + 1; i++, start+=inc, end+=inc)); do
  cut -f$start-$end "$infile" > "${infile}.$i"
done

Answer 2

if you only need a QAD (Quick & Dirty) solution for in my case a fixed 8 column ; separated csv

#!/bin/bash
# delimiter is ;
cut -d';' -f1 "$1" > "${1}.1"
cut -d';' -f2 "$1" > "${1}.2"
cut -d';' -f3 "$1" > "${1}.3"
cut -d';' -f4 "$1" > "${1}.4"
cut -d';' -f5 "$1" > "${1}.5"
cut -d';' -f6 "$1" > "${1}.6"
cut -d';' -f7 "$1" > "${1}.7"
cut -d';' -f8 "$1" > "${1}.8"

Answer 3

Thanks for the help. I hoped there would be a unix command similar to split, but I ended up wrapping the cut command with perl, via SiegeX's suggestion.

#!/usr/bin/perl

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


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

$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`;
    $start += $inc;
    $end += $inc;
}