signal: add support for looking up signals by number

Signed-off-by: Asbjørn Sloth Tønnesen <asbjorn@asbjorn.biz>
Signed-off-by: Emil Renner Berthing <esmil@mailme.dk>

3 files changed, 39 insertions, 6 deletions

diff --git a/lem/signal.lua b/lem/signal.lua
index ed3f4db..b3d84cb 100644
--- a/lem/signal.lua
+++ b/lem/signal.lua
@@ -72,13 +72,24 @@ do
 end
 
 local function lookup(signal)
-	return core.lookup(string.sub(signal, 4):upper())
+	if type(signal) == 'string' then
+		if string.sub(signal, 1, 3):upper() == 'SIG' then
+			signal = string.sub(signal, 4)
+		end
+		return core.tonumber(signal:upper())
+	else
+		local ret = core.tostring(signal)
+		if not ret then return nil end
+
+		return 'SIG' .. ret
+	end
 end
 
 local M = {}
 M.lookup = lookup
 
 function M.register(signal, func)
+	assert(type(signal) == 'string', 'signal should be a string')
 	local signum = lookup(signal)
 	if not signum then return nil, 'unknown signal' end
 
@@ -92,6 +103,7 @@ function M.register(signal, func)
 end
 
 function M.unregister(signal, func)
+	assert(type(signal) == 'string', 'signal should be a string')
 	local signum = lookup(signal)
 	if not signum then return nil, 'unknown signal' end
 
diff --git a/lem/signal/core.c b/lem/signal/core.c
index c5e297d..dacf4ea 100644
--- a/lem/signal/core.c
+++ b/lem/signal/core.c
@@ -239,7 +239,7 @@ signal_child_unwatch(lua_State *T)
 #endif
 
 static int
-signal_lookup(lua_State *T)
+signal_tonumber(lua_State *T)
 {
 	const char *needle = luaL_checkstring(T, 1);
 
@@ -257,6 +257,24 @@ signal_lookup(lua_State *T)
 }
 
 static int
+signal_tostring(lua_State *T)
+{
+	int needle = luaL_checkint(T, 1);
+
+	unsigned int i;
+
+	for (i = 0; i < ARRAYLEN(sigmap); i++) {
+		struct signal_mapping *sig = &sigmap[i];
+		if (sig->no == needle) {
+			lua_pushstring(T, sig->name);
+			return 1;
+		}
+	}
+	lua_pushnil(T);
+	return 1;
+}
+
+static int
 signal_sethandler(lua_State *T)
 {
 	int type;
@@ -318,9 +336,12 @@ luaopen_lem_signal_core(lua_State *T)
 	/* create module table */
 	lua_newtable(T);
 
-	/* set lookup function */
-	lua_pushcfunction(T, signal_lookup);
-	lua_setfield(T, -2, "lookup");
+	/* set tonumber function */
+	lua_pushcfunction(T, signal_tonumber);
+	lua_setfield(T, -2, "tonumber");
+	/* set tostring function */
+	lua_pushcfunction(T, signal_tostring);
+	lua_setfield(T, -2, "tostring");
 	/* set sethandler function */
 	lua_pushcfunction(T, signal_sethandler);
 	lua_setfield(T, -2, "sethandler");
diff --git a/test/signal.lua b/test/signal.lua
index 46c85a2..75e5429 100755
--- a/test/signal.lua
+++ b/test/signal.lua
@@ -39,7 +39,7 @@ io.popen(cmd)
 sleeper:sleep(1)
 
 local function handler(signum)
-	print('got signal number ' .. signum)
+	print('got ' .. signal.lookup(signum))
 end
 
 print('catch sigint')