1 /* 2 ** $Id: lua.c,v 1.206.1.1 2013/04/12 18:48:47 roberto Exp $ 3 ** Lua stand-alone interpreter 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #include <signal.h> 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include <string.h> 12 13 #define lua_c 14 15 #include "lua.h" 16 17 #include "lauxlib.h" 18 #include "lualib.h" 19 20 21 #if !defined(LUA_PROMPT) 22 #define LUA_PROMPT "> " 23 #define LUA_PROMPT2 ">> " 24 #endif 25 26 #if !defined(LUA_PROGNAME) 27 #define LUA_PROGNAME "lua" 28 #endif 29 30 #if !defined(LUA_MAXINPUT) 31 #define LUA_MAXINPUT 512 32 #endif 33 34 #if !defined(LUA_INIT) 35 #define LUA_INIT "LUA_INIT" 36 #endif 37 38 #define LUA_INITVERSION \ 39 LUA_INIT "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR 40 41 42 /* 43 ** lua_stdin_is_tty detects whether the standard input is a 'tty' (that 44 ** is, whether we're running lua interactively). 45 */ 46 #if defined(LUA_USE_ISATTY) 47 #include <unistd.h> 48 #define lua_stdin_is_tty() isatty(0) 49 #elif defined(LUA_WIN) 50 #include <io.h> 51 #include <stdio.h> 52 #define lua_stdin_is_tty() _isatty(_fileno(stdin)) 53 #else 54 #define lua_stdin_is_tty() 1 /* assume stdin is a tty */ 55 #endif 56 57 58 /* 59 ** lua_readline defines how to show a prompt and then read a line from 60 ** the standard input. 61 ** lua_saveline defines how to "save" a read line in a "history". 62 ** lua_freeline defines how to free a line read by lua_readline. 63 */ 64 #if defined(LUA_USE_READLINE) 65 66 #include <stdio.h> 67 #include <readline/readline.h> 68 #include <readline/history.h> 69 #define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL) 70 #define lua_saveline(L,idx) \ 71 if (lua_rawlen(L,idx) > 0) /* non-empty line? */ \ 72 add_history(lua_tostring(L, idx)); /* add it to history */ 73 #define lua_freeline(L,b) ((void)L, free(b)) 74 75 #elif !defined(lua_readline) 76 77 #define lua_readline(L,b,p) \ 78 ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \ 79 fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */ 80 #define lua_saveline(L,idx) { (void)L; (void)idx; } 81 #define lua_freeline(L,b) { (void)L; (void)b; } 82 83 #endif 84 85 86 87 88 static lua_State *globalL = NULL; 89 90 static const char *progname = LUA_PROGNAME; 91 92 93 94 static void lstop (lua_State *L, lua_Debug *ar) { 95 (void)ar; /* unused arg. */ 96 lua_sethook(L, NULL, 0, 0); 97 luaL_error(L, "interrupted!"); 98 } 99 100 101 static void laction (int i) { 102 signal(i, SIG_DFL); /* if another SIGINT happens before lstop, 103 terminate process (default action) */ 104 lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1); 105 } 106 107 108 static void print_usage (const char *badoption) { 109 luai_writestringerror("%s: ", progname); 110 if (badoption[1] == 'e' || badoption[1] == 'l') 111 luai_writestringerror("'%s' needs argument\n", badoption); 112 else 113 luai_writestringerror("unrecognized option '%s'\n", badoption); 114 luai_writestringerror( 115 "usage: %s [options] [script [args]]\n" 116 "Available options are:\n" 117 " -e stat execute string " LUA_QL("stat") "\n" 118 " -i enter interactive mode after executing " LUA_QL("script") "\n" 119 " -l name require library " LUA_QL("name") "\n" 120 " -v show version information\n" 121 " -E ignore environment variables\n" 122 " -- stop handling options\n" 123 " - stop handling options and execute stdin\n" 124 , 125 progname); 126 } 127 128 129 static void l_message (const char *pname, const char *msg) { 130 if (pname) luai_writestringerror("%s: ", pname); 131 luai_writestringerror("%s\n", msg); 132 } 133 134 135 static int report (lua_State *L, int status) { 136 if (status != LUA_OK && !lua_isnil(L, -1)) { 137 const char *msg = lua_tostring(L, -1); 138 if (msg == NULL) msg = "(error object is not a string)"; 139 l_message(progname, msg); 140 lua_pop(L, 1); 141 /* force a complete garbage collection in case of errors */ 142 lua_gc(L, LUA_GCCOLLECT, 0); 143 } 144 return status; 145 } 146 147 148 /* the next function is called unprotected, so it must avoid errors */ 149 static void finalreport (lua_State *L, int status) { 150 if (status != LUA_OK) { 151 const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1) 152 : NULL; 153 if (msg == NULL) msg = "(error object is not a string)"; 154 l_message(progname, msg); 155 lua_pop(L, 1); 156 } 157 } 158 159 160 static int traceback (lua_State *L) { 161 const char *msg = lua_tostring(L, 1); 162 if (msg) 163 luaL_traceback(L, L, msg, 1); 164 else if (!lua_isnoneornil(L, 1)) { /* is there an error object? */ 165 if (!luaL_callmeta(L, 1, "__tostring")) /* try its 'tostring' metamethod */ 166 lua_pushliteral(L, "(no error message)"); 167 } 168 return 1; 169 } 170 171 172 static int docall (lua_State *L, int narg, int nres) { 173 int status; 174 int base = lua_gettop(L) - narg; /* function index */ 175 lua_pushcfunction(L, traceback); /* push traceback function */ 176 lua_insert(L, base); /* put it under chunk and args */ 177 globalL = L; /* to be available to 'laction' */ 178 signal(SIGINT, laction); 179 status = lua_pcall(L, narg, nres, base); 180 signal(SIGINT, SIG_DFL); 181 lua_remove(L, base); /* remove traceback function */ 182 return status; 183 } 184 185 186 static void print_version (void) { 187 luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT)); 188 luai_writeline(); 189 } 190 191 192 static int getargs (lua_State *L, char **argv, int n) { 193 int narg; 194 int i; 195 int argc = 0; 196 while (argv[argc]) argc++; /* count total number of arguments */ 197 narg = argc - (n + 1); /* number of arguments to the script */ 198 luaL_checkstack(L, narg + 3, "too many arguments to script"); 199 for (i=n+1; i < argc; i++) 200 lua_pushstring(L, argv[i]); 201 lua_createtable(L, narg, n + 1); 202 for (i=0; i < argc; i++) { 203 lua_pushstring(L, argv[i]); 204 lua_rawseti(L, -2, i - n); 205 } 206 return narg; 207 } 208 209 210 static int dofile (lua_State *L, const char *name) { 211 int status = luaL_loadfile(L, name); 212 if (status == LUA_OK) status = docall(L, 0, 0); 213 return report(L, status); 214 } 215 216 217 static int dostring (lua_State *L, const char *s, const char *name) { 218 int status = luaL_loadbuffer(L, s, strlen(s), name); 219 if (status == LUA_OK) status = docall(L, 0, 0); 220 return report(L, status); 221 } 222 223 224 static int dolibrary (lua_State *L, const char *name) { 225 int status; 226 lua_getglobal(L, "require"); 227 lua_pushstring(L, name); 228 status = docall(L, 1, 1); /* call 'require(name)' */ 229 if (status == LUA_OK) 230 lua_setglobal(L, name); /* global[name] = require return */ 231 return report(L, status); 232 } 233 234 235 static const char *get_prompt (lua_State *L, int firstline) { 236 const char *p; 237 lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2"); 238 p = lua_tostring(L, -1); 239 if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2); 240 return p; 241 } 242 243 /* mark in error messages for incomplete statements */ 244 #define EOFMARK "<eof>" 245 #define marklen (sizeof(EOFMARK)/sizeof(char) - 1) 246 247 static int incomplete (lua_State *L, int status) { 248 if (status == LUA_ERRSYNTAX) { 249 size_t lmsg; 250 const char *msg = lua_tolstring(L, -1, &lmsg); 251 if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) { 252 lua_pop(L, 1); 253 return 1; 254 } 255 } 256 return 0; /* else... */ 257 } 258 259 260 static int pushline (lua_State *L, int firstline) { 261 char buffer[LUA_MAXINPUT]; 262 char *b = buffer; 263 size_t l; 264 const char *prmt = get_prompt(L, firstline); 265 int readstatus = lua_readline(L, b, prmt); 266 lua_pop(L, 1); /* remove result from 'get_prompt' */ 267 if (readstatus == 0) 268 return 0; /* no input */ 269 l = strlen(b); 270 if (l > 0 && b[l-1] == '\n') /* line ends with newline? */ 271 b[l-1] = '\0'; /* remove it */ 272 if (firstline && b[0] == '=') /* first line starts with `=' ? */ 273 lua_pushfstring(L, "return %s", b+1); /* change it to `return' */ 274 else 275 lua_pushstring(L, b); 276 lua_freeline(L, b); 277 return 1; 278 } 279 280 281 static int loadline (lua_State *L) { 282 int status; 283 lua_settop(L, 0); 284 if (!pushline(L, 1)) 285 return -1; /* no input */ 286 for (;;) { /* repeat until gets a complete line */ 287 size_t l; 288 const char *line = lua_tolstring(L, 1, &l); 289 status = luaL_loadbuffer(L, line, l, "=stdin"); 290 if (!incomplete(L, status)) break; /* cannot try to add lines? */ 291 if (!pushline(L, 0)) /* no more input? */ 292 return -1; 293 lua_pushliteral(L, "\n"); /* add a new line... */ 294 lua_insert(L, -2); /* ...between the two lines */ 295 lua_concat(L, 3); /* join them */ 296 } 297 lua_saveline(L, 1); 298 lua_remove(L, 1); /* remove line */ 299 return status; 300 } 301 302 303 static void dotty (lua_State *L) { 304 int status; 305 const char *oldprogname = progname; 306 progname = NULL; 307 while ((status = loadline(L)) != -1) { 308 if (status == LUA_OK) status = docall(L, 0, LUA_MULTRET); 309 report(L, status); 310 if (status == LUA_OK && lua_gettop(L) > 0) { /* any result to print? */ 311 luaL_checkstack(L, LUA_MINSTACK, "too many results to print"); 312 lua_getglobal(L, "print"); 313 lua_insert(L, 1); 314 if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != LUA_OK) 315 l_message(progname, lua_pushfstring(L, 316 "error calling " LUA_QL("print") " (%s)", 317 lua_tostring(L, -1))); 318 } 319 } 320 lua_settop(L, 0); /* clear stack */ 321 luai_writeline(); 322 progname = oldprogname; 323 } 324 325 326 static int handle_script (lua_State *L, char **argv, int n) { 327 int status; 328 const char *fname; 329 int narg = getargs(L, argv, n); /* collect arguments */ 330 lua_setglobal(L, "arg"); 331 fname = argv[n]; 332 if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0) 333 fname = NULL; /* stdin */ 334 status = luaL_loadfile(L, fname); 335 lua_insert(L, -(narg+1)); 336 if (status == LUA_OK) 337 status = docall(L, narg, LUA_MULTRET); 338 else 339 lua_pop(L, narg); 340 return report(L, status); 341 } 342 343 344 /* check that argument has no extra characters at the end */ 345 #define noextrachars(x) {if ((x)[2] != '\0') return -1;} 346 347 348 /* indices of various argument indicators in array args */ 349 #define has_i 0 /* -i */ 350 #define has_v 1 /* -v */ 351 #define has_e 2 /* -e */ 352 #define has_E 3 /* -E */ 353 354 #define num_has 4 /* number of 'has_*' */ 355 356 357 static int collectargs (char **argv, int *args) { 358 int i; 359 for (i = 1; argv[i] != NULL; i++) { 360 if (argv[i][0] != '-') /* not an option? */ 361 return i; 362 switch (argv[i][1]) { /* option */ 363 case '-': 364 noextrachars(argv[i]); 365 return (argv[i+1] != NULL ? i+1 : 0); 366 case '\0': 367 return i; 368 case 'E': 369 args[has_E] = 1; 370 break; 371 case 'i': 372 noextrachars(argv[i]); 373 args[has_i] = 1; /* go through */ 374 case 'v': 375 noextrachars(argv[i]); 376 args[has_v] = 1; 377 break; 378 case 'e': 379 args[has_e] = 1; /* go through */ 380 case 'l': /* both options need an argument */ 381 if (argv[i][2] == '\0') { /* no concatenated argument? */ 382 i++; /* try next 'argv' */ 383 if (argv[i] == NULL || argv[i][0] == '-') 384 return -(i - 1); /* no next argument or it is another option */ 385 } 386 break; 387 default: /* invalid option; return its index... */ 388 return -i; /* ...as a negative value */ 389 } 390 } 391 return 0; 392 } 393 394 395 static int runargs (lua_State *L, char **argv, int n) { 396 int i; 397 for (i = 1; i < n; i++) { 398 lua_assert(argv[i][0] == '-'); 399 switch (argv[i][1]) { /* option */ 400 case 'e': { 401 const char *chunk = argv[i] + 2; 402 if (*chunk == '\0') chunk = argv[++i]; 403 lua_assert(chunk != NULL); 404 if (dostring(L, chunk, "=(command line)") != LUA_OK) 405 return 0; 406 break; 407 } 408 case 'l': { 409 const char *filename = argv[i] + 2; 410 if (*filename == '\0') filename = argv[++i]; 411 lua_assert(filename != NULL); 412 if (dolibrary(L, filename) != LUA_OK) 413 return 0; /* stop if file fails */ 414 break; 415 } 416 default: break; 417 } 418 } 419 return 1; 420 } 421 422 423 static int handle_luainit (lua_State *L) { 424 const char *name = "=" LUA_INITVERSION; 425 const char *init = getenv(name + 1); 426 if (init == NULL) { 427 name = "=" LUA_INIT; 428 init = getenv(name + 1); /* try alternative name */ 429 } 430 if (init == NULL) return LUA_OK; 431 else if (init[0] == '@') 432 return dofile(L, init+1); 433 else 434 return dostring(L, init, name); 435 } 436 437 438 static int pmain (lua_State *L) { 439 int argc = (int)lua_tointeger(L, 1); 440 char **argv = (char **)lua_touserdata(L, 2); 441 int script; 442 int args[num_has]; 443 args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0; 444 if (argv[0] && argv[0][0]) progname = argv[0]; 445 script = collectargs(argv, args); 446 if (script < 0) { /* invalid arg? */ 447 print_usage(argv[-script]); 448 return 0; 449 } 450 if (args[has_v]) print_version(); 451 if (args[has_E]) { /* option '-E'? */ 452 lua_pushboolean(L, 1); /* signal for libraries to ignore env. vars. */ 453 lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); 454 } 455 /* open standard libraries */ 456 luaL_checkversion(L); 457 lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */ 458 luaL_openlibs(L); /* open libraries */ 459 lua_gc(L, LUA_GCRESTART, 0); 460 if (!args[has_E] && handle_luainit(L) != LUA_OK) 461 return 0; /* error running LUA_INIT */ 462 /* execute arguments -e and -l */ 463 if (!runargs(L, argv, (script > 0) ? script : argc)) return 0; 464 /* execute main script (if there is one) */ 465 if (script && handle_script(L, argv, script) != LUA_OK) return 0; 466 if (args[has_i]) /* -i option? */ 467 dotty(L); 468 else if (script == 0 && !args[has_e] && !args[has_v]) { /* no arguments? */ 469 if (lua_stdin_is_tty()) { 470 print_version(); 471 dotty(L); 472 } 473 else dofile(L, NULL); /* executes stdin as a file */ 474 } 475 lua_pushboolean(L, 1); /* signal no errors */ 476 return 1; 477 } 478 479 480 int main (int argc, char **argv) { 481 int status, result; 482 lua_State *L = luaL_newstate(); /* create state */ 483 if (L == NULL) { 484 l_message(argv[0], "cannot create state: not enough memory"); 485 return EXIT_FAILURE; 486 } 487 /* call 'pmain' in protected mode */ 488 lua_pushcfunction(L, &pmain); 489 lua_pushinteger(L, argc); /* 1st argument */ 490 lua_pushlightuserdata(L, argv); /* 2nd argument */ 491 status = lua_pcall(L, 2, 1, 0); 492 result = lua_toboolean(L, -1); /* get result */ 493 finalreport(L, status); 494 lua_close(L); 495 return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE; 496 } 497 498
