tardir.sh

#!/bin/bash
file="$@"
type=$(file $file | cut -d' ' -f2);
    case $type in
        POSIX)
            tdir=$(tar -tvf $file | sed q | awk '{ print $(NF)}' | sed 's/\///g')
            echo "$tdir"
            tar -xvf $file $tdir ;;
        gzip)
            tdir=$(tar -ztvf $file | sed q | awk '{ print $(NF)}' | sed 's/\///g')
            tar -xzf $file $tdir
            echo "$file $tdir" ;;
        bz2)
            tdir=$(tar -jtvf $file | sed q | awk '{ print $(NF)}' | sed 's/\///g')
            tar -xjf $file $tdir
            echo "$file $tdir" ;;
    esac

    if [[ -Z "$tdir" ]]; then
        echo "I could not determine that this is a valid tar archive"
    fi