zipScript.sh

#!/bin/bash

# Script that tries to handle tar commands in an intelligent way
# Disclaimer: This is a demo for the case statement, not a production-ready script!
# Use: mytar dir file
# This will compress the directory dir into file

# Use: mytar filename
# This will extract the file

if [[ ! $1 ]]; then 
	echo "Need a file or directory as first argument" >&2
	exit 1
fi

if [[ ! -e $1 ]]; then
	echo "File or directory $1 not found." >&2
	exit 2
fi

if [[ -d $1 ]]; then
	# Is a directory: create archive
	operation="c"
	if [[ ! $2 ]]; then
		echo "Need name of file or directory to create as second argument" >&2
		exit 1
	fi
	tarfile="$2"
	dir="$1"
else
	# Is (probably) a file: try to extract
	operation="x"
	tarfile="$1"
	dir=""
fi

case $tarfile in
	*.tgz|*.gz|*.gzip)
		zip="z"
		echo "Using gzip" >&2;;
	*.bz|*.bz2|*.bzip|*.bzip2)
		zip="j"
		echo "Using bzip2" >&2;;
	*.Z)
		zip="Z"
		echo "Using compress" >&2;;
	*.tar)
		zip=""
		echo "No compression used" >&2;;
	*)
		echo "Unknown extension: ${tarfile}" >&2
		exit 3;;
esac

command="tar ${operation}${zip}f $tarfile"
if [[ $dir ]]; then 
	command="${command} $dir"
fi

if ! $command; then	
	echo "Error: tar exited with status $?" >&2
	exit 4
fi

echo "Ok" >&2
exit 0