Using select to make simple menus

#!/bin/bash
OPTIONS="Hello Quit"
select opt in $OPTIONS; do
  if [ "$opt" = "Quit" ]; then
    echo done
    exit
  elif [ "$opt" = "Hello" ]; then
    echo Hello World
  else
    clear
    echo bad option
  fi
done

If you run this script you’ll see that it is a programmer’s dream for text based menus. You’ll probably notice that it’s very similar to the ‘for’ construction, only rather than looping for each ‘word’ in $OPTIONS, it prompts the user.

Using the command line

#!/bin/bash
if [ -z "$1" ]; then
  echo usage: $0 directory
  exit
fi
SRCD=$1
TGTD="/var/backups/"
OF=home-$(date +%Y%m%d).tgz
tar -cZf $TGTD$OF $SRCD

What this script does should be clear to you. The expression in the first conditional tests if the program has received an argument ($1) and quits if it didn’t, showing the user a little usage message. The rest of the script should be clear at this point.

Source: http://en.tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-9.html