#!/bin/sh
#this script checks for command line arguments
#this script also demonstrates the if-then-else control structure

#this line uses the test builtin to check if the number of command
#line arguments ($#) = 1 you can also use -eq if you are checking
#for an integer
#if you are writing a script that requires command line arguments
#you must first check for the correct arguments and then supply
#an error message or read in more argments see p. 338
if test $# = 1
	then 
		echo hey you entered a command line argument
	else
		echo you must enter exactly one command line argument
		exit 1
fi

#the exit 1 exits the program with abnormal terminate
#normal termination is for a program to exit 0, if you  
#go to the command line and type echo $? you can see the exit status
#of the last program run
#otherwise the program will continue to the next structure
#now you can look to page 372 for the differentoptions to test
#a file

if test -f "$1"
	then
		echo "$1 is a regular file in the working directory"
	else 
		echo "$1 is NOT a file in the working directory"
fi
#this is normal program termination

#<title>CSC128: Shell Scriptsa - Command line Arguments  </title>