| 1 | /* |
| 2 | ** $Id: lua.c,v 1.206 2012/09/29 20:07:06 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 | |