#!/bin/sh
# args: $1 - directory holding input files
#       $2 - column to save
#       $3 - output file
#  temporary files created in /tmp/columns

n=0

for i in $1/*; do
    n=`expr $n + 1`
    echo $i >/tmp/columns/$n
    cut -f $2 $i >>/tmp/columns/$n 
done
paste /tmp/columns/* >$3
rm /tmp/columns/*