#!/bin/bash

if [ ! $# -ge 1 ]; then
	echo "`basename $0`: missing file argument"
	echo " Usage: `basename $0` FILE [[COLUMN] ...] [DELIMITER]"
	exit 1
fi

tmp="${HOME}/.`basename $0`.tmp"
[ -f "${tmp}" ] && rm $tmp
touch $tmp

dlm="|"
cnt=0
for j in $@
do
	let cnt=${cnt}+1
	if [ $cnt -eq 1 ]; then
		if [ "${j}" = "-" ]; then
			file=$j
		elif [ -f "${j}" ]; then
			file=$j
		else
			echo "Error: file '`pwd`/${j}' not exists, exit program!"
			exit 1
		fi
	else
		chk=`echo $j | awk '{print ($0 !~ /[^0-9]/) ? 0 : 1}'`
		if [ $chk -eq 1 ]; then
			if [ $cnt -eq $# ]; then
				dlm=`echo $j | \
						awk '{print ($0 ~ /^[^0-9a-fA-F]$/) ? $0 : "\\\"}'` 
				if [ "${dlm}" = "\\" ]; then
					echo "Error: '${j}' is invalid delimiter, exit program!"
					exit 1
				fi
			else
				echo "Error: '${j}' is no column number, exit program!"
				exit 1
			fi
		else
			echo $j >> $tmp
		fi
	fi
done

awk 'BEGIN	{
				FS = ""
				split(ARGV[2], inp, "=")
				while(getline a[++n] < inp[2] > 0) {}
			}
			{
				str = ""
				for(i = 1; i <= (l = length($0)); i++)
				{
					str = str sprintf("%s", substr($0, i, 1))
					for(j in a)
						if(a[j] == i)
						{
							sub(/ +$/, "", str)
							str = str d
						}
					if(i == a[n])
						break
				}
				for(j in a)
					if(a[j] > l)
					{
						sub(/ +$/, "", str)
						str = str d
					}
				print str
			}' d=$dlm v=$tmp $file
rm $tmp

$ mkunl sourcefile 6 10 15 21 27 31 36 42 48 52 57 63