Use semicolon as file path separator for lua_load (#2154)

* Use semicolon as file path separator for lua_load.
* Resolve lua path in lua_load.
* Move llua_init to initialisation(), to ensure lua state is initialized before dealing with config file.
* Move package.path setup to llua_init so globals all get set from the same place.
* Handle paths with spaces correctly in `to_real_path` by escaping spaces.

Signed-off-by: Tin Švagelj <tin.svagelj@live.com>

doc/config_settings.yaml

@@ -266,7 +266,18 @@ values:
       - function_name
       - [function arguments]
   - name: lua_load
-    desc: Loads the Lua scripts separated by spaces.
+    desc: |-
+      List of Lua script paths to load at startup in order to provide Lua
+      functions for other hooks. Listed files are loaded (executed) before
+      'lua_startup_hook' and can (but shouldn't) run code in global scope.
+
+      Paths are ';' (semicolon) separated, and can be relative to the config
+      file path, or absolute.
+
+      The paths were previously ' ' (space) separated, this functionality is
+      still supported if ';' isn't found, but is deprecated and will be removed
+      in future versions. Empty paths are skipped so './example file.lua;' is
+      valid.
   - name: lua_mouse_hook
     desc: |-
       This function, if defined, will be called by Conky upon receiving mouse

src/common.cc

@@ -146,10 +146,14 @@ std::filesystem::path to_real_path(const std::string &source) {
   wordexp_t p;
   char **w;
   int i;
-  const char *csource = source.c_str();
+  std::string checked = std::string(source);
-  if (wordexp(csource, &p, 0) != 0) {
+  std::string::size_type n = 0;
-    return std::string();
+  while ((n = checked.find(" ", n)) != std::string::npos) {
+    checked.replace(n, 1, "\\ ");
+    n += 2;
   }
+  const char *csource = source.c_str();
+  if (wordexp(checked.c_str(), &p, 0) != 0) { return std::string(); }
   w = p.we_wordv;
   const char *resolved_path = strdup(w[0]);
   wordfree(&p);

src/conky.cc

@@ -121,7 +121,6 @@
 #include "data/timeinfo.h"
 #include "data/top.h"
 #include "logging.h"
-#include "lua/llua.h"
 #include "output/nc.h"
 
 #ifdef BUILD_MYSQL
@@ -134,6 +133,7 @@
 #include "data/network/ccurl_thread.h"
 #endif /* BUILD_CURL */
 
+#include "lua/llua.h"
 #include "lua/lua-config.hh"
 #include "lua/setting.hh"
 #include "output/display-output.hh"
@@ -1985,40 +1985,6 @@ void load_config_file() {
   lua::stack_sentry s(l);
   l.checkstack(2);
 
-  // Extend lua package.path so scripts can use relative paths
-  {
-    struct stat file_stat {};
-
-    std::string path_ext;
-
-    // add XDG directory to lua path
-    auto xdg_path =
-        std::filesystem::path(to_real_path(XDG_CONFIG_FILE)).parent_path();
-    if (stat(xdg_path.c_str(), &file_stat) == 0) {
-      path_ext.push_back(';');
-      path_ext.append(xdg_path);
-      path_ext.append("/?.lua");
-    }
-
-    auto parent_path = current_config.parent_path();
-    if (xdg_path != parent_path && stat(path_ext.c_str(), &file_stat) == 0) {
-      path_ext.push_back(';');
-      path_ext.append(parent_path);
-      path_ext.append("/?.lua");
-    }
-
-    l.getglobal("package");
-    l.getfield(-1, "path");
-
-    auto path = l.tostring(-1);
-    path.append(path_ext);
-    l.pop();
-    l.pushstring(path.c_str());
-
-    l.setfield(-2, "path");
-    l.pop();
-  }
-
   try {
 #ifdef BUILD_BUILTIN_CONFIG
     if (current_config == builtin_config_magic) {
@@ -2171,6 +2137,7 @@ void initialisation(int argc, char **argv) {
   set_default_configurations();
 
   set_current_config();
+  llua_init();
   load_config_file();
 
   /* handle other command line arguments */

src/lua/llua.cc

@@ -22,18 +22,22 @@
  */
 #include "config.h"
 
-#include "build.h"
+#include <cstring>
+#include <filesystem>
+#include <sstream>
+
 #include "../conky.h"
 #include "../geometry.h"
-#include "llua.h"
 #include "../logging.h"
+#include "build.h"
+#include "llua.h"
 
 #ifdef BUILD_GUI
 #include "../output/gui.h"
 
 #ifdef BUILD_X11
-#include "x11-settings.h"
 #include "../output/x11.h"
+#include "x11-settings.h"
 #endif /* BUILD_X11 */
 
 #ifdef BUILD_MOUSE_EVENTS
@@ -75,13 +79,26 @@ class lua_load_setting : public conky::simple_config_setting<std::string> {
 
     if (init) {
       std::string files = do_convert(l, -1).first;
-      while (!files.empty()) {
+
-        std::string::size_type pos = files.find(' ');
+      // Split file names into separate `\0` strings
-        if (pos > 0) {
+      if (files.find(';') != std::string::npos) {
-          std::string file(files, 0, pos);
+        for (auto &ch : files) {
-          llua_load(file.c_str());
+          if (ch == ';') { ch = '\0'; }
         }
-        files.erase(0, pos == std::string::npos ? pos : pos + 1);
+      } else {
+        // TODO: Remove space-delimited file name handling in 3 years (2028.)
+        for (auto &ch : files) {
+          if (ch == ' ') { ch = '\0'; }
+        }
+      }
+
+      const char *start = files.c_str();
+      const char *end = start + files.size();
+      while (start < end) {
+        if (*start != '\0') {  // Skip empty strings
+          llua_load(start);
+        }
+        start += strlen(start) + 1;
       }
     }
 
@@ -94,7 +111,6 @@ class lua_load_setting : public conky::simple_config_setting<std::string> {
 #ifdef HAVE_SYS_INOTIFY_H
     llua_rm_notifies();
 #endif /* HAVE_SYS_INOTIFY_H */
-    if (lua_L == nullptr) { return; }
     lua_close(lua_L);
     lua_L = nullptr;
   }
@@ -171,15 +187,50 @@ void llua_init() {
 
   /* add our library path to the lua package.cpath global var */
   luaL_openlibs(lua_L);
-  lua_getglobal(lua_L, "package");
+  lua_getglobal(lua_L, "package");   // stack: package
-  lua_getfield(lua_L, -1, "cpath");
+  lua_getfield(lua_L, -1, "cpath");  // stack: package.cpath, package
 
   old_path = std::string(lua_tostring(lua_L, -1));
   new_path = libs + old_path;
 
-  lua_pushstring(lua_L, new_path.c_str());
+  lua_pushstring(lua_L,
-  lua_setfield(lua_L, -3, "cpath");
+                 new_path.c_str());  // stack: new_path, package.cpath, package
-  lua_pop(lua_L, 2);
+  lua_setfield(lua_L, -3, "cpath");  // stack: package.cpath, package
+  lua_pop(lua_L, 1);                 // stack: package
+
+  /* Add config file and XDG paths to package.path so scripts can load other
+   * scripts from relative paths */
+  {
+    struct stat file_stat{};
+
+    std::string path_ext;
+
+    // add XDG directory to lua path
+    auto xdg_path =
+        std::filesystem::path(to_real_path(XDG_CONFIG_FILE)).parent_path();
+    if (stat(xdg_path.c_str(), &file_stat) == 0) {
+      path_ext.append(xdg_path);
+      path_ext.append("/?.lua");
+      path_ext.push_back(';');
+    }
+
+    auto parent_path = current_config.parent_path();
+    if (xdg_path != parent_path && stat(path_ext.c_str(), &file_stat) == 0) {
+      path_ext.append(parent_path);
+      path_ext.append("/?.lua");
+      path_ext.push_back(';');
+    }
+
+    lua_getfield(lua_L, -1, "path");  // stack: package.path, package
+    old_path = std::string(lua_tostring(lua_L, -1));
+    new_path = path_ext + old_path;
+
+    lua_pushstring(lua_L,
+                   new_path.c_str());  // stack: new_path, package.path, package
+    lua_setfield(lua_L, -3, "path");   // stack: package.path, package
+    lua_pop(lua_L, 1);                 // stack: package
+  }
+  lua_pop(lua_L, 1);  // stack is empty
 
   lua_pushstring(lua_L, PACKAGE_NAME " " VERSION " compiled for " BUILD_ARCH);
   lua_setglobal(lua_L, "conky_build_info");
@@ -216,17 +267,46 @@ inline bool file_exists(const char *path) {
 void llua_load(const char *script) {
   int error;
 
-  std::string path = to_real_path(script);
+  std::filesystem::path path = to_real_path(script);
 
   if (!file_exists(path.c_str())) {
-    NORM_ERR("llua_load: specified script file '%s' doesn't exist",
+    bool found_alternative = false;
-             path.c_str());
-    // return without initializing lua_L because other parts of the code rely
-    // on it being null if the script is not loaded
-    return;
-  }
 
-  llua_init();
+    // Try resolving file name by using files in lua path:
+    lua_getglobal(lua_L, "package");  // stack: package
+    lua_getfield(lua_L, -1, "path");  // stack: package.path, package
+    auto lua_path = lua_tostring(lua_L, -1);
+    lua_pop(lua_L, 2);  // stack is empty
+
+    std::stringstream path_stream(lua_path);
+    std::string current;
+    while (std::getline(path_stream, current, ';')) {
+      // lua_load conky variable accepts full file names, so replace "?.lua"
+      // with "?" to ensure file names don't get the unexpected .lua suffix; but
+      // modules with init.lua will still work.
+      size_t substitute_pos = current.find("?.lua");
+      if (substitute_pos != std::string::npos) {
+        current.replace(substitute_pos, 5, "?");
+      }
+
+      substitute_pos = current.find('?');
+      if (substitute_pos == std::string::npos) { continue; }
+      current.replace(substitute_pos, 1, script);
+      path = to_real_path(current);
+
+      if (file_exists(path.c_str())) {
+        found_alternative = true;
+        break;
+      }
+    }
+
+    if (!found_alternative) {
+      NORM_ERR("llua_load: specified script file '%s' doesn't exist", script);
+      // return without initializing lua_L because other parts of the code rely
+      // on it being null if the script is not loaded
+      return;
+    }
+  }
 
   error = luaL_dofile(lua_L, path.c_str());
   if (error != 0) {
@@ -347,8 +427,6 @@ static char *llua_getstring(const char *args) {
   char *func;
   char *ret = nullptr;
 
-  if (lua_L == nullptr) { return nullptr; }
-
   func = llua_do_call(args, 1);
   if (func != nullptr) {
     if (lua_isstring(lua_L, -1) == 0) {
@@ -392,8 +470,6 @@ static char *llua_getstring_read(const char *function, const char *arg)
 static int llua_getnumber(const char *args, double *ret) {
   char *func;
 
-  if (lua_L == nullptr) { return 0; }
-
   func = llua_do_call(args, 1);
   if (func != nullptr) {
     if (lua_isnumber(lua_L, -1) == 0) {
@@ -489,32 +565,30 @@ void llua_set_number(const char *key, double value) {
 }
 
 void llua_startup_hook() {
-  if ((lua_L == nullptr) || lua_startup_hook.get(*state).empty()) { return; }
+  if (lua_startup_hook.get(*state).empty()) { return; }
   llua_do_call(lua_startup_hook.get(*state).c_str(), 0);
 }
 
 void llua_shutdown_hook() {
-  if ((lua_L == nullptr) || lua_shutdown_hook.get(*state).empty()) { return; }
+  if (lua_shutdown_hook.get(*state).empty()) { return; }
   llua_do_call(lua_shutdown_hook.get(*state).c_str(), 0);
 }
 
 #ifdef BUILD_GUI
 void llua_draw_pre_hook() {
-  if ((lua_L == nullptr) || lua_draw_hook_pre.get(*state).empty()) { return; }
+  if (lua_draw_hook_pre.get(*state).empty()) { return; }
   llua_do_call(lua_draw_hook_pre.get(*state).c_str(), 0);
 }
 
 void llua_draw_post_hook() {
-  if ((lua_L == nullptr) || lua_draw_hook_post.get(*state).empty()) { return; }
+  if (lua_draw_hook_post.get(*state).empty()) { return; }
   llua_do_call(lua_draw_hook_post.get(*state).c_str(), 0);
 }
 
 #ifdef BUILD_MOUSE_EVENTS
 template <typename EventT>
 bool llua_mouse_hook(const EventT &ev) {
-  if ((lua_L == nullptr) || lua_mouse_hook.get(*state).empty()) {
+  if (lua_mouse_hook.get(*state).empty()) { return false; }
-    return false;
-  }
   const std::string raw_hook_name = lua_mouse_hook.get(*state);
   std::string hook_name;
   if (raw_hook_name.rfind("conky_", 0) == 0) {
@@ -579,7 +653,6 @@ void llua_set_userdata(const char *key, const char *type, void *value) {
 }
 
 void llua_setup_window_table(conky::rect<int> text_rect) {
-  if (lua_L == nullptr) { return; }
   lua_newtable(lua_L);
 
 #ifdef BUILD_X11
@@ -611,8 +684,6 @@ void llua_setup_window_table(conky::rect<int> text_rect) {
 }
 
 void llua_update_window_table(conky::rect<int> text_rect) {
-  if (lua_L == nullptr) { return; }
-
   lua_getglobal(lua_L, "conky_window");
   if (lua_isnil(lua_L, -1)) {
     /* window table isn't populated yet */
@@ -635,7 +706,6 @@ void llua_update_window_table(conky::rect<int> text_rect) {
 #endif /* BUILD_GUI */
 
 void llua_setup_info(struct information *i, double u_interval) {
-  if (lua_L == nullptr) { return; }
   lua_newtable(lua_L);
 
   llua_set_number("update_interval", u_interval);
@@ -645,8 +715,6 @@ void llua_setup_info(struct information *i, double u_interval) {
 }
 
 void llua_update_info(struct information *i, double u_interval) {
-  if (lua_L == nullptr) { return; }
-
   lua_getglobal(lua_L, "conky_info");
   if (lua_isnil(lua_L, -1)) {
     /* window table isn't populated yet */

src/lua/llua.h

@@ -44,6 +44,7 @@ extern "C" {
 void llua_inotify_query(int wd, int mask);
 #endif /* HAVE_SYS_INOTIFY_H */
 
+void llua_init();
 void llua_startup_hook(void);
 void llua_shutdown_hook(void);