ba8b5c17 |
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 | |