# This script demonstrates the ‹rm› command, which primarily removes
# (unlinks) files. It can, however, also remove directories and it
# can remove entire directory trees recursively. First some simple
# cases:

set -x

touch file # recall that this creates an empty file
ls file    # does it exist?
rm file    # remove it
ls file    # check again
rm file    # this prints an error, since ‹file› no longer exists

rm -f file # not an error -- this just ensures the file is not there
mkdir dir
rm dir     # this is an error
rm -d dir  # this works (but is non-standard, even if common)

touch file
rm -d file # this also works

# Now let's try something more complicated (and dangerous!):

mkdir -p dir/subdir/stuff
touch dir/subdir/stuff/file
touch dir/file
rm -d dir  # fails
rmdir dir  # also fails
rm -df dir # still fails
rm -r dir  # finally! r is for recursive

# For extra power (and danger), you could say ‹rm -rf›. Always
# remember that ‹rm› does not ask before deleting all your data. If
# you are unsure about the command, use ‹rm -i›, like this:

touch some_file
rm -i some_file

# That's about as much as we need to know about removing files and
# directories using user-level commands. Let's have a look at
# ‹unlink.c› now.