bin/svc: New script

2 files changed, 135 insertions, 0 deletions

diff --git a/.gitignore.d/homerc b/.gitignore.d/homerc
index 66206ac..b674cd2 100644
--- a/.gitignore.d/homerc
+++ b/.gitignore.d/homerc
@@ -6,6 +6,7 @@
 !/.gitignore.d/homerc
 !/bin/
 !/bin/rc
+!/bin/svc
 
 # Exclude swap and backup files
 *.s[a-w]?
diff --git a/bin/svc b/bin/svc
new file mode 100755
index 0000000..5587c6d
--- /dev/null
+++ b/bin/svc
@@ -0,0 +1,134 @@
+#!/bin/sh
+
+set -eu
+
+XDG_DATA_HOME=
+XDG_CONFIG_HOME=
+XDG_DATA_DIRS=
+XDG_CONFIG_DIRS=
+XDG_CACHE_HOME=
+PIDDIR=
+SERVICES=
+
+# TODO: "[....] service" output if attached to a tty
+
+load_service()
+{
+	local service="${1}"
+	shift 1
+
+	XDG_DATA_HOME="${XDG_DATA_HOME:-${HOME}/.local/share}"
+	XDG_CONFIG_HOME="${XDG_CONFIG_HOME:-${HOME}/.config}"
+	XDG_DATA_DIRS="${XDG_DATA_DIRS:-/usr/local/share/:/usr/share/}"
+	XDG_CONFIG_DIRS="${XDG_CONFIG_DIRS:-/etc/xdg}"
+	XDG_CACHE_HOME="${XDG_CACHE_HOME:-${HOME}/.cache}"
+	PIDDIR="${XDG_CACHE_HOME}/homerc"
+
+	# Default functions
+	stop() { :; }
+	restart() { stop; start; }
+	status() { :; }
+
+	# TODO: Errors
+	. "${XDG_CONFIG_HOME}/homerc/${service}"
+}
+
+act()
+{
+	local action="${1}"
+	shift 1
+
+	"${action}"
+	return ${?}
+}
+
+match_session()
+{
+	local needle="${1}"
+	local haystack="${2}"
+	shift 2
+	local hay=
+
+	IFS=','
+	for hay in ${haystack}; do
+		unset IFS
+		case "${hay}" in
+			'') continue;;
+			"${needle}" | "${needle}:"*) return 0;;
+		esac
+	done
+	unset IFS
+
+	return 1
+}
+
+chg_sessions()
+{
+	local old_sessions="${1}"
+	local new_sessions="${2}"
+	shift 2
+	local is_running=
+	local should_run=
+
+	is_running=false
+	should_run=false
+	for session in ${SESSIONS}; do
+		if match_session "${session}" "${old_sessions}"; then
+			is_running=true
+		fi
+		if match_session "${session}" "${new_sessions}"; then
+			should_run=true
+		fi
+	done
+
+	if ${is_running} && ! ${should_run}; then
+		act 'stop'
+		return ${?}
+	fi
+	if ! ${is_running} && ${should_run}; then
+		act 'start'
+		return ${?}
+	fi
+
+	# No change.
+	return 0
+}
+
+usage()
+{
+	printf 'Usage: %s <service> {start|stop|restart|status}\n' "${progname}"
+
+	return 0
+}
+
+main()
+{
+	local service=
+	local action=
+
+	if [ ${#} -ne 2 ]; then
+		usage 1>&2
+		return 1
+	fi
+	service="${1}"
+	action="${2}"
+
+	case "${action}" in
+		'start' | 'stop' | 'restart' | 'status')
+			load_service "${service}" || return 1
+			act "${action}"
+			;;
+		*';'*)
+			load_service "${service}" || return 1
+			chg_sessions "${action%%;*}" "${action#*;}"
+			;;
+		*)
+			usage 1>&2
+			return 1
+			;;
+	esac
+
+	return 0
+}
+
+main "${@}"