Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
esac
◊ Quoting the variables is not mandatory, since word splitting does not take
place.
◊ Each test line ends with a right paren ).
◊ Each condition block ends with a double semicolon ;;.
◊ The entire case block terminates with an esac (case spelled backwards).
Example 10−24. Using case
#!/bin/bash
echo; echo "Hit a key, then hit return."
read Keypress
case "$Keypress" in
[a−z] ) echo "Lowercase letter";;
[A−Z] ) echo "Uppercase letter";;
[0−9] ) echo "Digit";;
* ) echo "Punctuation, whitespace, or other";;
esac # Allows ranges of characters in [square brackets].
# Exercise:
# −−−−−−−−
# As the script stands, # it accepts a single keystroke, then terminates.
# Change the script so it accepts continuous input,
# reports on each keystroke, and terminates only when "X" is hit.
# Hint: enclose everything in a "while" loop.
exit 0
Example 10−25. Creating menus using case
#!/bin/bash
# Crude address database
clear # Clear the screen.
echo "
Contact List"
echo "
−−−−−−− −−−−"
echo "Choose one of the following persons:"
echo
echo "[E]vans, Roland"
echo "[J]ones, Mildred"
echo "[S]mith, Julie"
echo "[Z]ane, Morris"
echo
read person
case "$person" in
# Note variable is quoted.
"E" | "e" )
Chapter 10. Loops and Branches 118