1 files changed, 110 insertions, 0 deletions
diff --git a/processes.lua b/processes.lua
new file mode 100644
index 0000000..4ba61e8
--- /dev/null
+++ b/processes.lua
@@ -0,0 +1,110 @@
+local P = {}
+
+-- Shell-safe quoting: wraps in single quotes, escapes inner quotes
+local function shell_quote(str)
+	return "'" .. tostring(str):gsub("'", "'\"'\"'") .. "'"
+end
+
+-- Build a safe shell command from argv
+local function build_cmd(argv)
+	local quoted = {}
+	for i, arg in ipairs(argv) do
+		quoted[i] = shell_quote(arg)
+	end
+	return table.concat(quoted, " ")
+end
+
+--- Check if a process matching the given pattern is running.
+--- Uses `pgrep -f -- <pattern>`
+--- @param pattern string
+function P.is_running(pattern)
+	local cmd = build_cmd({ "pgrep", "-f", "--", pattern })
+	local h = io.popen(cmd)
+	if not h then
+		return false
+	end
+	local r = h:read("*l")
+	h:close()
+	return r ~= nil
+end
+
+--- @class waywall
+--- @field exec fun(cmd: string): nil
+
+--- wrapper around waywall.exec
+--- @param ww waywall
+--- @param argv table array-like table of args
+--- @return nil
+function P.ww_exec_argv(ww, argv)
+	-- No quoting needed; execvp-style expects raw argv
+	assert(type(argv) == "table", "argv must be an array-like table of strings")
+	for i, v in ipairs(argv) do
+		assert(type(v) == "string", "argv element must be a string")
+	end
+	local cmd = table.concat(argv, " ")
+	return ww.exec(cmd)
+end
+
+--- Return a function that starts an application when called.
+--- @param ww waywall waywall dependency
+--- @param app_path string path to the application executable
+--- @param args? string[] optional additional arguments to pass to the application
+--- @return fun(): nil
+function P.start_application(ww, app_path, args)
+	return function()
+		local argv = { app_path }
+		if args then
+			for _, a in ipairs(args) do
+				argv[#argv + 1] = a
+			end
+		end
+		P.ww_exec_argv(ww, argv)(ww, argv)
+	end
+end
+
+--- Ensure an application is running, start it if not.
+--- @param ww waywall waywall dependency
+--- @param app_path string path to the application executable
+--- @param args? string[] optional additional arguments to pass to the application
+--- @return fun(pattern: string): fun(): nil
+function P.ensure_application(ww, app_path, args)
+	return function(pattern)
+		return function()
+			if not P.is_running(pattern) then
+				local argv = { app_path }
+				if args then
+					for _, a in ipairs(args) do
+						argv[#argv + 1] = a
+					end
+				end
+				P.ww_exec_argv(ww, argv)
+			end
+		end
+	end
+end
+
+--- Ensure a Java JAR is running, start it if not.
+--- @param ww waywall
+--- @param java_path string path to java executable
+--- @param jar_path string path to the JAR file
+--- @param args? string[] optional additional arguments to pass to java
+--- @return fun(pattern: string): fun(): nil
+function P.ensure_java_jar(ww, java_path, jar_path, args)
+	return function(pattern)
+		return function()
+			if not P.is_running(pattern) then
+				local argv = { java_path }
+				if args then
+					for _, a in ipairs(args) do
+						argv[#argv + 1] = a
+					end
+				end
+				argv[#argv + 1] = "-jar"
+				argv[#argv + 1] = jar_path
+				P.ww_exec_argv(ww, argv)
+			end
+		end
+	end
+end
+
+return P