Lab Solution: Using the case Statement
Create a file named testcase.sh, with the content below.
#!/bin/bash

# Accept a number between 1 and 12 as
# an argument to this script, then return the
# the name of the month that corresponds to that number.

# Check to see if the user passed a parameter.
if [ $# -eq 0 ]
then
  echo "Error. Give as an argument a number between 1 and 12."
  exit 1
fi

# set month equal to argument passed for use in the script
month=$1

################################################
# The example of a case statement:

case $month in

  1)  echo "January"   ;;
  2)  echo "February"  ;;
  3)  echo "March"     ;;
  4)  echo "April"     ;;
  5)  echo "May"       ;;
  6)  echo "June"      ;;
  7)  echo "July"      ;;
  8)  echo "August"    ;;
  9)  echo "September" ;;
  10) echo "October"   ;;
  11) echo "November"  ;;
  12) echo "December"  ;;
  *)
     echo "Error. No month matches: $month"
     echo "Please pass a number between 1 and 12."
     exit 2
     ;;
esac
exit 0
Make it executable and run it:
student:/tmp> chmod +x testcase.sh
student:/tmp> ./testcase.sh 5
May
student:/tmp> ./testcase.sh 12

December

student:/tmp> ./testcase.sh 99

Error. No month matches: 99
Please pass a number between 1 and 12
student:/tmp>