Wrapper script for extracting different types of archives

extract.sh

#!/bin/bash

function extract {
    cmd=$1
    filename=$2
    fullname=$3

    echo "$fullname"
    mkdir "$filename"
    cd "$filename"
    $cmd "../$fullname" || echo "*** ERROR ***"
    cd ..
}

for filename in *.*
do
    fullname=$filename
    extension="${filename#*.}"
    filename="${filename%%.*}"
    case $extension in
        zip)
            cmd="unzip"
            ;;
        tar*.gz)
            cmd="tar xzvf"
            ;;
        tar)
            cmd="tar xvf"
            ;;
        7z)
            cmd="7z x"
            ;;
        *)
            echo
            echo "*** ${fullname}: no known extractor for $extension"
            echo
            continue
            ;;
    esac
    extract "$cmd" "$filename" "$fullname"
done