Advanced Bash−Scripting Guide

Advanced Bash−Scripting Guide
#!/bin/bash
E_WRONG_DIRECTORY=73
clear # Clear screen.
TargetDirectory=/home/bozo/projects/GreatAmericanNovel
cd $TargetDirectory
echo "Deleting stale files in $TargetDirectory."
if [ "$PWD" != "$TargetDirectory" ]
then # Keep from wiping out wrong directory by accident.
echo "Wrong directory!"
echo "In $PWD, rather than $TargetDirectory!"
echo "Bailing out!"
exit $E_WRONG_DIRECTORY
fi
rm −rf *
rm .[A−Za−z0−9]* # Delete dotfiles.
# rm −f .[^.]* ..?* to remove filenames beginning with multiple dots.
# (shopt −s dotglob; rm −f *) will also work.
# Thanks, S.C. for pointing this out.
# Filenames may contain all characters in the 0 − 255 range, except "/".
# Deleting files beginning with weird characters is left as an exercise.
# Various other operations here, as necessary.
echo
echo "Done."
echo "Old files deleted in $TargetDirectory."
echo
exit 0
$REPLY
The default value when a variable is not supplied to read. Also applicable to select menus, but only
supplies the item number of the variable chosen, not the value of the variable itself.
#!/bin/bash
echo
echo −n "What is your favorite vegetable? "
read
echo "Your favorite vegetable is $REPLY."
# REPLY holds the value of last "read" if and only if
# no variable supplied.
echo
echo −n "What is your favorite fruit? "
read fruit
echo "Your favorite fruit is $fruit."
echo "but..."
echo "Value of \$REPLY is still $REPLY."
# $REPLY is still set to its previous value because
# the variable $fruit absorbed the new "read" value.
echo
Chapter 9. Variables Revisited 69