one single bash script stowsh to replace stow

stowsh

#!/usr/bin/env bash

_runcommands() {
	if [[ $DRYRUN == 1 ]] || [[ $VERBOSE -gt 1 ]]; then
		echo "$@"
	fi
	if [[ $DRYRUN != 1 ]]; then
		eval "$@"
	fi
}

echoerr() {
	printf "%s\n" "$*" >&2;
}

deperr() {
	echoerr "stowsh requires $1"
}

isgnu() {
	if $1 --version >/dev/null 2>&1 ; then
		return 1
	else
		return 0
	fi
}

stowsh_setpaths() {
	if command -v grealpath >/dev/null 2>&1; then
		rpcmd="grealpath"
	elif command -v realpath >/dev/null 2>&1; then
		rpcmd="realpath"
	else
		deperr "GNU coreutils"
		return 1
	fi
	if isgnu $rpcmd; then
		deperr "GNU coreutils"
		return 1
	fi
	if command -v gfind >/dev/null 2>&1; then
		findcmd="gfind"
	elif command -v find >/dev/null 2>&1; then
		findcmd="find"
	else
		deperr "GNU findutils"
		return 1
	fi
	if isgnu $findcmd; then
		deperr "GNU findutils"
		return 1
	fi
}

stowsh_install() {
	stowsh_setpaths || return 1
	local pkg=$("$rpcmd" "$1")
	local target=$HOME

	while IFS= read -r -d '' d; do
		target=$(echo "$target/$(basename $d)")
		if test -L "${target}"; then
			echo $target is already a symbolic link...
			echo
			break
		fi
		if test -f "${target}" || test -d "${target}"; then
			d=$($findcmd $d -mindepth 1 -maxdepth 1 -print0)
			target=$(echo "$target/$(basename $d)")
			if test -L "${target}"; then
				echo $target is already a symbolic link...
				echo
				break
			fi
			_runcommands "ln -v -s $d $target"
			echo
			break
		else
			_runcommands "ln -v -s $d $target"
			echo
			break
		fi
	done < <($findcmd $pkg -mindepth 1 -iname ".*" -print0)
}

stowsh_uninstall() {
	stowsh_setpaths || return 1
	local pkg=$1
	local target=$HOME

	while IFS= read -r -d '' d; do
		target=$(echo "$target/$(basename $d)")
		if ! test -L "${target}"; then
			d=$($findcmd $d -mindepth 1 -maxdepth 1 -print0)
			target=$(echo "$target/$(basename $d)")
			if ! test -L "${target}"; then
				echo $target is not a symbolic link...
			else
				_runcommands "rm -rfv $target"
			fi
			echo
			break
		else
			_runcommands "rm -rfv $target"
			echo
			break
		fi
	done < <($findcmd $pkg -mindepth 1 -iname ".*" -print0)
}

stowsh_help() {
	cat <<EOF
$(basename $0) -- One single bash script to replace the GNU stow

Usage: $(basename $0) [-r] [-n] [-s] [-v[v]] PACKAGES...
              -r uninstall a package
              -n dry-run (print what would happen, but don't do anything)
              -v verbose (-vv is even more verbose)
              -s skip (skip errors rather than abort)
EOF
}

if [ "$0" = "$BASH_SOURCE" ]; then
	UNINSTALL=0
	DRYRUN=0
	SKIP=0
	PACKAGES=()
	while [[ "$@" ]]; do
		if [[ $1 =~ ^- ]]; then
			OPTIND=1
			while getopts ":vhrsnt:" opt; do
				case $opt in
					h)
						stowsh_help
						exit 0
						;;
					r)  UNINSTALL=1
						;;
					n)  DRYRUN=1
						;;
					s)  SKIP=1
						;;
					v)  VERBOSE=$((VERBOSE + 1))
						;;
					*)  echo "'$OPTARG' is an invalid option/flag"
						exit 1
						;;
				esac
			done
			shift $((OPTIND-1))
		else
			PACKAGES+=("$1")
			shift
		fi
	done

	if [[ ${#PACKAGES[@]} -eq 0 ]] ; then
		stowsh_help
		exit 1
	fi

	for i in ${!PACKAGES[*]}; do
		pkg=${PACKAGES[$i]}
		if [[ $UNINSTALL -eq 1 ]]; then
			if [[ $VERBOSE -gt 0 ]] ; then echoerr "Uninstalling $pkg" ; fi
			stowsh_uninstall "$pkg"
		else
			if [[ $VERBOSE -gt 0 ]] ; then echoerr "Installing $pkg" ; fi
			stowsh_install "$pkg"
		fi
	done
fi