#!/usr/bin/env sh
# compat: +ash +bash +dash -hush -ksh +mksh -oksh +osh +posh +yash +zsh

v_lower() { ### @- transform the contents of a variable to lowercase.
    argc $# -eq 1 "$0" || return
    map() {
        case "$_i_" in
        (A) _o_=a;; (B) _o_=b;; (C) _o_=c;; (D) _o_=d;; (E) _o_=e;; (F) _o_=f;; (G) _o_=g;;
        (H) _o_=h;; (I) _o_=i;; (J) _o_=j;; (K) _o_=k;; (L) _o_=l;; (M) _o_=m;; (N) _o_=n;;
        (O) _o_=o;; (P) _o_=p;; (Q) _o_=q;; (R) _o_=r;; (S) _o_=s;; (T) _o_=t;; (U) _o_=u;;
        (V) _o_=v;; (W) _o_=w;; (X) _o_=x;; (Y) _o_=y;; (Z) _o_=z;; (*) _o_="$_i_";;
        esac
    }
    v_domap "$1"
}

[ -n "${preload+-}" ] || . ~/sh/preload || exit 2
eval ${preload:-preload} argc v_domap
[ -n "${preload+-}" ] || v_lower "$@"