#!/bin/sh
#notice that the function refers to the positional parameter $1
#the $1 only exists within the function, it does not affect 
#the $1 from the command line


error_fn()
{
  echo "ERROR: $1"
  echo "ERROR: $2"
  exit 1
}

#here in the function the "you need..." becomes $1
if [ $# -ne 2 ]
then
  echo '$1' from the command line is $1
  error_fn "you need at least 2 arguments" "this is the second arg"
fi
echo "The contents of the first directory you entered are:"
ls -l $1 

if [ $? -ne 0 ]
then
  echo '$1' from the command line is $1
else
  error_fn "Your internal command didn't work "
fi

#now I will check the second arg
echo "The contents of the second directory you entered are:"
ls $2

#this checks to see if the "ls $2" exited correctly
if [ $? -ne 0 ]
then
  error_fn "could not read the second directory: $2"
fi


#<title>CSC128: Shell Script Examples - functions in bash  </title>