Korn Shell: Unix and Linux Programming Manual, Third Edition, The

Display Files - kcat

Here is a simple Korn shell version of the Unix cat command. It is only 3-4 times slower than the Unix version (on a 100-line file), because it uses the exec command for the file I/O.

					#!/bin/ksh
					#
					#     kcat - Korn shell version of cat
					#
					# Check usage
					if (($# < 1))
					then
					print "Usage: $0 file ..."
					exit 1
					fi
					# Process each file
					while (($# > 0))
					do
					# Make sure file exists
					if [[ ! -f $1 ]]
					then
					print "$1: non-existent or not accessible"
					else
					# Open file for input
					exec 0<$1
					while read LINE
					do
					# Display output
					print $LINE
					done
					fi
					# Get next file argument
					shift
					done