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

rtl_check_path_vars() {
	local _vnames="${1}" _rc=0 _vname="" _vname_val=""; _status="";
	for _vname in ${_vnames}; do
		_vname_val="$(rtl_get_var_unsafe "${_vname}")";
		if [ -z "${_vname_val}" ]; then
			_rc=1; _status="Error: variable \`${_vname}' is empty or unset."; break;
		elif [ "${_vname_val#* *}" != "${_vname_val}" ]; then
			_rc=2; _status="Error: variable \`${_vname}' contains one or more whitespace characters."; break;
		fi;
	done;
	return "${_rc}";
};

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_dirname() {
	local _dname="${1%/*}";
	while rtl_matchr "${_dname}" "*/"; do
		_dname="${_dname%/}";
	done; printf "%s" "${_dname:-/}";
};

rtl_exists_any() {
	local _subdir="${1}"; shift;
	while [ "${#}" -gt 0 ]; do
		if [ -e "${_subdir}/${1}" ]; then
			return 0;
		else
			shift;
		fi;
	done; return 1;
};

rtl_export_vars() {
	local _unsetfl=0; [ "x${1}" = "x-u" ] && { _unsetfl=1; shift; };
	while [ "${#}" -ge 2 ]; do
		if [ -n "${2}" ]; then
			if [ "${_unsetfl:-0}" -eq 0 ]; then
				rtl_set_var_unsafe "${1}" "${2}"; export "${1}";
			else
				unset "${1}";
			fi;
		fi;
		shift 2;
	done;
};

rtl_filter_vars() {
	local _fn="${1}" _fnfl=0 _qchar="" _var_spec="" _vars="" _vname="" IFS;
	rtl_set_IFS_nl;
	for _var_spec in $(set); do
		case "${_qchar}" in
		"\"")	if [ "${_var_spec%\"}" != "${_var_spec}" ]; then
				_qchar="";
			fi;
			if [ "${_fnfl:-0}" -eq 1 ]; then
				_vars="$(rtl_lconcat "${_vars}" "${_var_spec}" "\n")";
			fi;
			continue; ;;
		"\'")	if [ "${_var_spec%\'}" != "${_var_spec}" ]; then
				_qchar="";
			fi;
			if [ "${_fnfl:-0}" -eq 1 ]; then
				_vars="$(rtl_lconcat "${_vars}" "${_var_spec}" "\n")";
			fi;
			continue; ;;
		*)	case "${_var_spec}" in
			[^=]*=\"*\")	_qchar=""; _vname="${_var_spec%%=\"*}"; ;;
			[^=]*=\"*)	_qchar="\""; _vname="${_var_spec%%=\"*}"; ;;
			[^=]*=\'*\')	_qchar=""; _vname="${_var_spec%%=\'*}"; ;;
			[^=]*=\'*)	_qchar="\'"; _vname="${_var_spec%%=\'*}"; ;;
			[^=]*=*)	_qchar=""; _vname="${_var_spec%%=*}"; ;;
			esac; ;;
		esac;
		if "${_fn}" "${_vname}"; then
			_vars="${_vars:+${_vars}
}${_var_spec}"; _fnfl=1;
		else
			_fnfl=0;
		fi;
	done;
	printf "%s" "${_vars}";
};

rtl_flock_acquire() {
	local _fd="${1}" _conflict_exit_code="${2:-622}" _wait="${3:-3600}"
	while true; do
		if flock -E "${_conflict_exit_code}" -w "${_wait}" "${_fd}"; then
			break;
		elif [ "${?}" -eq "${_conflict_exit_code}" ]; then
			continue;
		else
			return "${?}";
		fi;
	done;
};

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_head() {
	local _pattern="${1}" _s="${2}";
	while true; do
		if [ "${_s%%${_pattern}}" = "${_s}" ]; then
			break;
		else
			_s="${_s%%${_pattern}}";
		fi;
	done;
	printf "%s" "${_s}";
};

rtl_is_newer() {
	local _new_fname="${1}" _old_fname="${2}" _new_ts="" _old_ts="";
	if ! [ -e "${_old_fname}" ]; then
		return 0;
	else	_new_ts="$(stat -c %Y "${_new_fname}" 2>&1)";
		_old_ts="$(stat -c %Y "${_old_fname}" 2>&1)";
		if [ "${_new_ts:-0}" -gt "${_old_ts:-0}" ]; then
			return 0;
		else
			return 1;
		fi;
	fi;
};

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 notice "Command line: %s %s" "${_cmd}" "${*}";
		else
			rtl_log_msg notice "Command line: %s" "${_cmd}";
		fi; ;;
	*)	"${_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}";
		_vval_src="$(rtl_get_var_unsafe "${_vname_src}")";
		if [ -n "${_vval_src}" ]; then
			rtl_set_var_unsafe "PKG_${_vname_dst}" "${_vval_src}";
			_vars_set_tmp="$(rtl_lconcat "${_vars_set_tmp}" "PKG_${_vname_dst}")";
		fi;
	done;
	_vars_set_old="$(rtl_get_var_unsafe "${_vars_set_vname}")";
	rtl_set_var_unsafe "${_vars_set_vname}"					\
		"$(rtl_lconcat "${_vars_set_old}" "${_vars_set_tmp}")";
};

# vim:filetype=sh