korncd

linux脚本编程的例子

cd()
{
    case "$#" in
        0 | 1)  builtin cd $1 ;;
        2    )  newdir=$(echo $PWD | sed -e "s:$1:$2:g")
                case "$newdir" in
                    $PWD)   echo "bash: cd: bad substitution" >&2 ; return 1 ;;
                    *   )   builtin cd "$newdir" ;;
                esac ;;
        *    )  echo "bash: cd: wrong arg count" 1>&2 ; return 1 ;;
    esac
}