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

Display Files with Line Numbers - knl

This is a simple Korn shell version of the Unix nl command. It displays line-numbered output.

					#!/bin/ksh
					#
					#     knl - Korn Shell line-numbering filter
					#
					# Initialize line number counter
					integer LNUM=1
					# Check usage
					if (($# == 0))
					then
					print "Usage: $0 file . . ."
					exit 1
					fi
					# Process each file
					for FILE
					do
					# Make sure file exists
					if [[ ! -f $FILE ]]
					then
					print "$FILE: non-existent or not readable"
					exit 1
					else
					# Open file for reading
					exec 0<$FILE
					# Read each line, print out with line number
					while read -r LINE
					do
					print "$LNUM: $LINE"
					((LNUM+=1))
					done
					fi
					# Reset line number counter
					LNUM=1
					done