#
# set +o errexit -o noglob -o nounset is assumed.
#

rtl_check_prereqs() {
	local _cmd="" _cmds_missing="" _rc=0; _status="";
	for _cmd in "${@}"; do
		if ! which "${_cmd}" >/dev/null 2>&1; then
			_cmds_missing="${_cmds_missing:+${_cmds_missing} }${_cmd}";
		fi;
	done;
	if [ -n "${_cmds_missing}" ]; then
		_rc=1; _status="Error: missing prerequisite package(s): ${_cmds_missing}";
	fi;
	return "${_rc}";
};

rtl_clean_env() {
	local _env_vars_except="${1}" _env_var="" _env_vars="";
	_env_vars="$(export | sed -ne '/^export/{s/^export //;s/=.*$//p}')";
	for _env_var in ${_env_vars}; do
		if [ "${_env_var#DEFAULT_}" != "${_env_var}" ]\
		|| [ "${_env_var#PKG_}" != "${_env_var}" ]; then
			_env_vars_except="$(rtl_lconcat "${_env_vars_except}" "${_env_var}")";
		fi;
	done;
	rtl_unset_vars $(rtl_lfilter "${_env_vars}" "${_env_vars_except}");
};

rtl_get_cpu_count() {
	local _line="" _ncpus=0 _rc=0 _sname="$(uname -s 2>/dev/null)"; _status="";
	case "${_sname}" in
	Linux)	if [ ! -e "/proc/cpuinfo" ]; then
			_rc=1; _status="Error: /proc/cpuinfo non-existent.";
		else	while read -r _line; do
				if rtl_match "${_line}" "processor*:"; then
					: $((_ncpus+=1));
				fi;
			done < /proc/cpuinfo; printf "%s" "${_ncpus}";
		fi; ;;
	*)	_rc=1; _status="Error: unknown platform \`${_sname}'."; ;;
	esac; return "${_rc}";
};

rtl_get_var_unsafe() {
	local _vname="";
	if [ "x${1}" = "x-u" ]; then
		shift; _vname="$(rtl_toupper "${1}")";
	else
		_vname="${1}";
	fi;
	eval echo \${${_vname}} 2>/dev/null;
};

rtl_get_vars_fast() {
	local _pattern="${1}";
	set | awk -F= '/'"${_pattern}"'/{print $1}' | sort;
};

rtl_kill_tree() {
	local _pid="${1}" _signal="${2:-TERM}" _pid_child="" _pids="";
	if _pids="$(pgrep -P "${_pid}")"\
	&& [ -n "${_pids}" ]; then
		for _pid_child in ${_pids}; do
			rtl_kill_tree "${_pid_child}" "${_signal}";
		done;
	fi;
	if [ "${_pid:-0}" -ne "${$}" ]\
	&& kill "-${_signal}" "${_pid}" 2>/dev/null; then
		RTL_KILL_TREE_PIDS="$(rtl_lconcat "${RTL_KILL_TREE_PIDS}" "${_pid}")";
	fi;
};

rtl_prompt() {
	local _fmt="${1}" _choice=""; shift;
	printf "${_fmt}? (y|N) " "${@}";
	read -r _choice;
	case "${_choice}" in
	[yY])	_choice=1; ;;
	*)	_choice=0; ;;
	esac;
	return "${_choice}";
};

rtl_rc() {
	local _nflag="${1}" _cmd="${2}"; shift 2;
	case "${_nflag}" in
	1)	     if [ "${#}" -gt 0 ]; then
			rtl_log_msg "verbose" "${MSG_rtl_platform_rc1}" "${_cmd}" "${*}";
		else
			rtl_log_msg "verbose" "${MSG_rtl_platform_rc2}" "${_cmd}";
		fi; ;;
	*)	"${_cmd}" "${@}";
	esac;
};

rtl_run_cmd_unsplit() {
	local _cmd="${1}" _cmdline="" _rc="" IFS; shift;
	while [ ${#} -gt 0 ]; do
		[ -n "${1}" ] &&\
			_cmdline="${_cmdline:+${_cmdline}:}${1}";
		shift;
	done;
	IFS=:; ${_cmd} ${_cmdline}; _rc=$?;
	return ${_rc};
};

rtl_set_vars() {
	local	_vars_set_vname="${1}" _vname_dst="${2}" _vname_src_tmpls="${3}"	\
		_vars_set_old="" _vars_set_tmp="" _vname_src="";

	for _vname_src in $(rtl_toupper "${_vname_src_tmpls}"); do
		_vname_src="${_vname_src}_${_vname_dst}";
		eval _vval_src='${'"${_vname_src}"':-}';
		if [ "${_vval_src:+1}" = 1 ]; then
			eval PKG_${_vname_dst}='${_vval_src}';
			_vars_set_tmp="${_vars_set_tmp:+${_vars_set_tmp} }PKG_${_vname_dst}";
		fi;
	done;
	eval _vars_set_old='${'"${_vars_set_vname}"'}';
	rtl_set_var_unsafe "${_vars_set_vname}" "${_vars_set_old:+${_vars_set_old} }${_vars_set_tmp}";
};

# vim:filetype=sh