Put a Lua filter's print output where it runs

LuaJIT and Lua 5.1 leave print's line in stdio's buffer until cgit
exits, after the end of the page.

1 file changed, 31 insertions, 0 deletions

diff --git a/source/filter.c b/source/filter.cindex 6cc5e80..82d8725 100644--- a/source/filter.c+++ b/source/filter.c@@ -293,6 +293,36 @@ static int script_html_include(lua_State *lua_state) 	return emit_unfiltered(lua_state, html_include); } +/*+ * The print of LuaJIT and Lua 5.1 leaves its line in stdio's buffer, which+ * reaches stdout only when cgit exits, after the end of the page. This one+ * builds the same line, each value through tostring with a tab between them,+ * and writes it as html does.+ */+static int script_print(lua_State *lua_state)+{+	int i, count = lua_gettop(lua_state);+	luaL_Buffer line;++	lua_getglobal(lua_state, "tostring");+	luaL_buffinit(lua_state, &line);+	for (i = 1; i <= count; i++) {+		if (i > 1)+			luaL_addchar(&line, '\t');+		lua_pushvalue(lua_state, count + 1);+		lua_pushvalue(lua_state, i);+		lua_call(lua_state, 1, 1);+		if (!lua_isstring(lua_state, -1))+			return luaL_error(lua_state, "'tostring' must return a string to 'print'");+		luaL_addvalue(&line);+	}+	luaL_addchar(&line, '\n');+	luaL_pushresult(&line);+	// emit_unfiltered takes its text from the first slot.+	lua_replace(lua_state, 1);+	return emit_unfiltered(lua_state, html);+}+ static const struct { 	const char *name; 	lua_CFunction fn;@@ -303,6 +333,7 @@ static const struct { 	{ "html_url_path", script_html_url_path }, 	{ "html_url_arg", script_html_url_arg }, 	{ "html_include", script_html_include },+	{ "print", script_print }, };  static void init_lua_filter(struct lua_filter *filter)
diff --git a/source/filter.c b/source/filter.c
index 6cc5e80..82d8725 100644
--- a/source/filter.c
+++ b/source/filter.c
@@ -293,6 +293,36 @@ static int script_html_include(lua_State *lua_state)
 	return emit_unfiltered(lua_state, html_include);
 }
 
+/*
+ * The print of LuaJIT and Lua 5.1 leaves its line in stdio's buffer, which
+ * reaches stdout only when cgit exits, after the end of the page. This one
+ * builds the same line, each value through tostring with a tab between them,
+ * and writes it as html does.
+ */
+static int script_print(lua_State *lua_state)
+{
+	int i, count = lua_gettop(lua_state);
+	luaL_Buffer line;
+
+	lua_getglobal(lua_state, "tostring");
+	luaL_buffinit(lua_state, &line);
+	for (i = 1; i <= count; i++) {
+		if (i > 1)
+			luaL_addchar(&line, '\t');
+		lua_pushvalue(lua_state, count + 1);
+		lua_pushvalue(lua_state, i);
+		lua_call(lua_state, 1, 1);
+		if (!lua_isstring(lua_state, -1))
+			return luaL_error(lua_state, "'tostring' must return a string to 'print'");
+		luaL_addvalue(&line);
+	}
+	luaL_addchar(&line, '\n');
+	luaL_pushresult(&line);
+	// emit_unfiltered takes its text from the first slot.
+	lua_replace(lua_state, 1);
+	return emit_unfiltered(lua_state, html);
+}
+
 static const struct {
 	const char *name;
 	lua_CFunction fn;
@@ -303,6 +333,7 @@ static const struct {
 	{ "html_url_path", script_html_url_path },
 	{ "html_url_arg", script_html_url_arg },
 	{ "html_include", script_html_include },
+	{ "print", script_print },
 };
 
 static void init_lua_filter(struct lua_filter *filter)