From Lua 5.2: Add -E command line option (ignore env vars).

etc/luajit.1

@@ -41,6 +41,9 @@ Run in interactive mode.
 .B "\-v"
 Show \fBLuaJIT\fR version.
 .TP
+.B "\-E"
+Ignore environment variables.
+.TP
 .B "\-\-"
 Stop processing options.
 .TP

src/lib_package.c

@@ -517,7 +517,7 @@ static int lj_cf_package_seeall(lua_State *L)
 #define AUXMARK		"\1"
 
 static void setpath(lua_State *L, const char *fieldname, const char *envname,
-		    const char *def)
+		    const char *def, int noenv)
 {
 #if LJ_TARGET_CONSOLE
   const char *path = NULL;
@@ -525,7 +525,7 @@ static void setpath(lua_State *L, const char *fieldname, const char *envname,
 #else
   const char *path = getenv(envname);
 #endif
-  if (path == NULL) {
+  if (path == NULL || noenv) {
     lua_pushstring(L, def);
   } else {
     path = luaL_gsub(L, path, LUA_PATHSEP LUA_PATHSEP,
@@ -562,6 +562,7 @@ static const lua_CFunction package_loaders[] =
 LUALIB_API int luaopen_package(lua_State *L)
 {
   int i;
+  int noenv;
   luaL_newmetatable(L, "_LOADLIB");
   lj_lib_pushcf(L, lj_cf_package_unloadlib, 1);
   lua_setfield(L, -2, "__gc");
@@ -574,8 +575,11 @@ LUALIB_API int luaopen_package(lua_State *L)
     lua_rawseti(L, -2, i+1);
   }
   lua_setfield(L, -2, "loaders");
-  setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT);
-  setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT);
+  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
+  noenv = lua_toboolean(L, -1);
+  lua_pop(L, 1);
+  setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT, noenv);
+  setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT, noenv);
   lua_pushliteral(L, LUA_PATH_CONFIG);
   lua_setfield(L, -2, "config");
   luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 16);

src/luajit.c

@@ -71,6 +71,7 @@ static void print_usage(void)
   "  -O[opt]   Control LuaJIT optimizations.\n"
   "  -i        Enter interactive mode after executing " LUA_QL("script") ".\n"
   "  -v        Show version information.\n"
+  "  -E        Ignore environment variables.\n"
   "  --        Stop handling options.\n"
   "  -         Execute stdin and stop handling options.\n"
   ,
@@ -406,6 +407,7 @@ static int dobytecode(lua_State *L, char **argv)
 #define FLAGS_VERSION		2
 #define FLAGS_EXEC		4
 #define FLAGS_OPTION		8
+#define FLAGS_NOENV		16
 
 static int collectargs(char **argv, int *flags)
 {
@@ -442,6 +444,9 @@ static int collectargs(char **argv, int *flags)
       if (*flags) return -1;
       *flags |= FLAGS_EXEC;
       return 0;
+    case 'E':
+      *flags |= FLAGS_NOENV;
+      break;
     default: return -1;  /* invalid option */
     }
   }
@@ -521,23 +526,30 @@ static int pmain(lua_State *L)
   globalL = L;
   if (argv[0] && argv[0][0]) progname = argv[0];
   LUAJIT_VERSION_SYM();  /* linker-enforced version check */
-  lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */
-  luaL_openlibs(L);  /* open libraries */
-  lua_gc(L, LUA_GCRESTART, -1);
-  s->status = handle_luainit(L);
-  if (s->status != 0) return 0;
   script = collectargs(argv, &flags);
   if (script < 0) {  /* invalid args? */
     print_usage();
     s->status = 1;
     return 0;
   }
+  if ((flags & FLAGS_NOENV)) {
+    lua_pushboolean(L, 1);
+    lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
+  }
+  lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */
+  luaL_openlibs(L);  /* open libraries */
+  lua_gc(L, LUA_GCRESTART, -1);
+  if (!(flags & FLAGS_NOENV)) {
+    s->status = handle_luainit(L);
+    if (s->status != 0) return 0;
+  }
   if ((flags & FLAGS_VERSION)) print_version();
   s->status = runargs(L, argv, (script > 0) ? script : s->argc);
   if (s->status != 0) return 0;
-  if (script)
+  if (script) {
     s->status = handle_script(L, argv, script);
-  if (s->status != 0) return 0;
+    if (s->status != 0) return 0;
+  }
   if ((flags & FLAGS_INTERACTIVE)) {
     print_jit_status(L);
     dotty(L);