Using a Counter Loop for Environment Variable

Question

I'm trying to write a code that moves files to a .junk directory using the built-in environment variables. My goal is that all a user would have to do is type sh junk filename1 filename2 filename3... and the script would use $1, $2, $3... to move the files. Unfortunately I can't quite get the counter loop to work correctly.

#!/bin/s if [ $# = 0 ] then echo "Usage: junk -l | -p | { filename }*" elif [ $1 = "-l" ] && [ $HOME/.junk ] then ls $HOME/.junk elif [ $1 = "-p" ] && [ $HOME/.junk ] then rm -r $HOME/.junk elif [ $1 = "$@" ] && [ $HOME/.junk ] then echo $# i=1 s="$" while [ $i -le $# ] do echo $s$i mv $s$i .junk/$i i=$(($i+1)) done fi 

Answer 1

Some immediate problems:

1. Use getopts for argument processing or have a reason why not.
2. If the script is given more than 1 argument, the "$@" in the third elif will blow it up.
3. Use a for f in "$@" loop instead of a while loop.

Why?

1. What happens if you type sh junk --help ... or some more interesting mv option?
2. QED
3. Simpler => Better

Answer 2

#!/bin/sh junkdir="$HOME/.junk" do_list=false do_purge=false while getopts 'lp' opt; do case "$opt" in l) do_list=true ;; p) do_purge=true ;; *) printf 'Usage: %s [-l|-p] [ name ... ]\n' "$0" >&2 exit 1 esac done shift "$(( OPTIND - 1 ))" if [ ! -d "$junkdir" ] && ! "$do_purge"; then printf '%s: Missing junk directory "%s"\n' "$0" "$junkdir" >&2 printf '%s: Re-run with -p to create it\n' "$0" >&2 exit 1 fi if "$do_list"; then printf 'Current junk in "%s":\n' "$junkdir" ls -l "$junkdir" fi if "$do_purge"; then printf 'Emptying junk directory "%s"\n' "$junkdir" rm -rf "$junkdir" mkdir "$junkdir" fi if [ "$#" -eq 0 ]; then exit fi echo 'Junking the following things:' printf '%s\n' "$@" mv "$@" "$junkdir" 

This script implements what it is you're trying to do. It uses getopts to parse the command line flags -l and/or -p.

I'm setting do_list and do_purge in the while loop that parses the command line option because I want to control the order in which the ls and the rm takes place further down. If a user uses -lp or -pl I want them to see the contents of the junk directory before it is removed.

Removing the junk directory with -p also recreates it. I do this with rm -rf followed by mkdir for simplicity.

After the command line parsing loop, I adjust the positional parameters so that they only contain non-option arguments (names of files and/or directories).

If there are no positional arguments ($# is zero), I don't try to run mv to move files to the junk directory.