do_increment

Advanced Bash&#8722 Scripting Guide An in&#8722 depth exploration of the art of shell scripting Me

#!/bin/sh
# Script name: do_increment
increment ()  {
    sum=`expr $1 + 1`
    return $sum	  # Return the value of sum to the script.
} 

echo  -n "The sum is "
increment 5	# Call function increment; pass 5 as a
		# parameter. 5 becomes $1 for the increment 
		# function.
echo $?		# The return value is stored in $?
echo  $sum	# The variable "sum" is known to the function, 
		# and is also known to the main script.