#!/bin/sh
#	map f:		takes a list of items on stdin, and applies the given
#			transformation to each of them.
case $# in
  1) ;;
  *) echo "$0: expected one cmdline argument" >&2
     exit 1 ;;
esac
transform=$1
read line
until [ -z "$line" ]
do
  $transform $line
  read line
done