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
lstop(lua_State * L,lua_Debug * ar)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
laction(int i)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
print_usage(const char * badoption)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
l_message(const char * pname,const char * msg)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
report(lua_State * L,int status)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 */
finalreport(lua_State * L,int status)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
traceback(lua_State * L)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
docall(lua_State * L,int narg,int nres)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
print_version(void)186 static void print_version (void) {
187 luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));
188 luai_writeline();
189 }
190
191
getargs(lua_State * L,char ** argv,int n)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
dofile(lua_State * L,const char * name)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
dostring(lua_State * L,const char * s,const char * name)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
dolibrary(lua_State * L,const char * name)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
get_prompt(lua_State * L,int firstline)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
incomplete(lua_State * L,int status)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
pushline(lua_State * L,int firstline)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
loadline(lua_State * L)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
dotty(lua_State * L)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
handle_script(lua_State * L,char ** argv,int n)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
collectargs(char ** argv,int * args)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
runargs(lua_State * L,char ** argv,int n)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
handle_luainit(lua_State * L)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
pmain(lua_State * L)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
main(int argc,char ** argv)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