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 #ifdef SYSLINUX
9 #include <console.h>
10 #define signal(x,y)
11 #else
12 #include <signal.h>
13 #endif
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17
18 #define lua_c
19
20 #include "lua.h"
21
22 #include "lauxlib.h"
23 #include "lualib.h"
24
25
26 #if !defined(LUA_PROMPT)
27 #define LUA_PROMPT "> "
28 #define LUA_PROMPT2 ">> "
29 #endif
30
31 #if !defined(LUA_PROGNAME)
32 #define LUA_PROGNAME "lua"
33 #endif
34
35 #if !defined(LUA_MAXINPUT)
36 #define LUA_MAXINPUT 512
37 #endif
38
39 #if !defined(LUA_INIT)
40 #define LUA_INIT "LUA_INIT"
41 #endif
42
43 #define LUA_INITVERSION \
44 LUA_INIT "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
45
46
47 /*
48 ** lua_stdin_is_tty detects whether the standard input is a 'tty' (that
49 ** is, whether we're running lua interactively).
50 */
51 #if defined(LUA_USE_ISATTY)
52 #include <unistd.h>
53 #define lua_stdin_is_tty() isatty(0)
54 #elif defined(LUA_WIN)
55 #include <io.h>
56 #include <stdio.h>
57 #define lua_stdin_is_tty() _isatty(_fileno(stdin))
58 #else
59 #define lua_stdin_is_tty() 1 /* assume stdin is a tty */
60 #endif
61
62
63 /*
64 ** lua_readline defines how to show a prompt and then read a line from
65 ** the standard input.
66 ** lua_saveline defines how to "save" a read line in a "history".
67 ** lua_freeline defines how to free a line read by lua_readline.
68 */
69 #if defined(LUA_USE_READLINE)
70
71 #include <stdio.h>
72 #include <readline/readline.h>
73 #include <readline/history.h>
74 #define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL)
75 #define lua_saveline(L,idx) \
76 if (lua_rawlen(L,idx) > 0) /* non-empty line? */ \
77 add_history(lua_tostring(L, idx)); /* add it to history */
78 #define lua_freeline(L,b) ((void)L, free(b))
79
80 #elif !defined(lua_readline)
81
82 #define lua_readline(L,b,p) \
83 ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \
84 fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */
85 #define lua_saveline(L,idx) { (void)L; (void)idx; }
86 #define lua_freeline(L,b) { (void)L; (void)b; }
87
88 #endif
89
90
91
92
93 static lua_State *globalL = NULL;
94
95 static const char *progname = LUA_PROGNAME;
96
97
98
99 #ifndef SYSLINUX
lstop(lua_State * L,lua_Debug * ar)100 static void lstop (lua_State *L, lua_Debug *ar) {
101 (void)ar; /* unused arg. */
102 lua_sethook(L, NULL, 0, 0);
103 luaL_error(L, "interrupted!");
104 }
105
106
laction(int i)107 static void laction (int i) {
108 signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
109 terminate process (default action) */
110 lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
111 }
112 #endif
113
114
print_usage(const char * badoption)115 static void print_usage (const char *badoption) {
116 luai_writestringerror("%s: ", progname);
117 if (badoption[1] == 'e' || badoption[1] == 'l')
118 luai_writestringerror("'%s' needs argument\n", badoption);
119 else
120 luai_writestringerror("unrecognized option '%s'\n", badoption);
121 luai_writestringerror(
122 "usage: %s [options] [script [args]]\n"
123 "Available options are:\n"
124 " -e stat execute string " LUA_QL("stat") "\n"
125 " -i enter interactive mode after executing " LUA_QL("script") "\n"
126 " -l name require library " LUA_QL("name") "\n"
127 " -v show version information\n"
128 " -E ignore environment variables\n"
129 " -- stop handling options\n"
130 " - stop handling options and execute stdin\n"
131 ,
132 progname);
133 }
134
135
l_message(const char * pname,const char * msg)136 static void l_message (const char *pname, const char *msg) {
137 if (pname) luai_writestringerror("%s: ", pname);
138 luai_writestringerror("%s\n", msg);
139 }
140
141
report(lua_State * L,int status)142 static int report (lua_State *L, int status) {
143 if (status != LUA_OK && !lua_isnil(L, -1)) {
144 const char *msg = lua_tostring(L, -1);
145 if (msg == NULL) msg = "(error object is not a string)";
146 l_message(progname, msg);
147 lua_pop(L, 1);
148 /* force a complete garbage collection in case of errors */
149 lua_gc(L, LUA_GCCOLLECT, 0);
150 }
151 return status;
152 }
153
154
155 /* the next function is called unprotected, so it must avoid errors */
finalreport(lua_State * L,int status)156 static void finalreport (lua_State *L, int status) {
157 if (status != LUA_OK) {
158 const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1)
159 : NULL;
160 if (msg == NULL) msg = "(error object is not a string)";
161 l_message(progname, msg);
162 lua_pop(L, 1);
163 }
164 }
165
166
traceback(lua_State * L)167 static int traceback (lua_State *L) {
168 const char *msg = lua_tostring(L, 1);
169 if (msg)
170 luaL_traceback(L, L, msg, 1);
171 else if (!lua_isnoneornil(L, 1)) { /* is there an error object? */
172 if (!luaL_callmeta(L, 1, "__tostring")) /* try its 'tostring' metamethod */
173 lua_pushliteral(L, "(no error message)");
174 }
175 return 1;
176 }
177
178
docall(lua_State * L,int narg,int nres)179 static int docall (lua_State *L, int narg, int nres) {
180 int status;
181 int base = lua_gettop(L) - narg; /* function index */
182 lua_pushcfunction(L, traceback); /* push traceback function */
183 lua_insert(L, base); /* put it under chunk and args */
184 globalL = L; /* to be available to 'laction' */
185 signal(SIGINT, laction);
186 status = lua_pcall(L, narg, nres, base);
187 signal(SIGINT, SIG_DFL);
188 lua_remove(L, base); /* remove traceback function */
189 return status;
190 }
191
192
print_version(void)193 static void print_version (void) {
194 luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));
195 luai_writeline();
196 }
197
198
getargs(lua_State * L,char ** argv,int n)199 static int getargs (lua_State *L, char **argv, int n) {
200 int narg;
201 int i;
202 int argc = 0;
203 while (argv[argc]) argc++; /* count total number of arguments */
204 narg = argc - (n + 1); /* number of arguments to the script */
205 luaL_checkstack(L, narg + 3, "too many arguments to script");
206 for (i=n+1; i < argc; i++)
207 lua_pushstring(L, argv[i]);
208 lua_createtable(L, narg, n + 1);
209 for (i=0; i < argc; i++) {
210 lua_pushstring(L, argv[i]);
211 lua_rawseti(L, -2, i - n);
212 }
213 return narg;
214 }
215
216
dofile(lua_State * L,const char * name)217 static int dofile (lua_State *L, const char *name) {
218 int status = luaL_loadfile(L, name);
219 if (status == LUA_OK) status = docall(L, 0, 0);
220 return report(L, status);
221 }
222
223
dostring(lua_State * L,const char * s,const char * name)224 static int dostring (lua_State *L, const char *s, const char *name) {
225 int status = luaL_loadbuffer(L, s, strlen(s), name);
226 if (status == LUA_OK) status = docall(L, 0, 0);
227 return report(L, status);
228 }
229
230
dolibrary(lua_State * L,const char * name)231 static int dolibrary (lua_State *L, const char *name) {
232 int status;
233 lua_getglobal(L, "require");
234 lua_pushstring(L, name);
235 status = docall(L, 1, 1); /* call 'require(name)' */
236 if (status == LUA_OK)
237 lua_setglobal(L, name); /* global[name] = require return */
238 return report(L, status);
239 }
240
241
get_prompt(lua_State * L,int firstline)242 static const char *get_prompt (lua_State *L, int firstline) {
243 const char *p;
244 lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2");
245 p = lua_tostring(L, -1);
246 if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
247 return p;
248 }
249
250 /* mark in error messages for incomplete statements */
251 #define EOFMARK "<eof>"
252 #define marklen (sizeof(EOFMARK)/sizeof(char) - 1)
253
incomplete(lua_State * L,int status)254 static int incomplete (lua_State *L, int status) {
255 if (status == LUA_ERRSYNTAX) {
256 size_t lmsg;
257 const char *msg = lua_tolstring(L, -1, &lmsg);
258 if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) {
259 lua_pop(L, 1);
260 return 1;
261 }
262 }
263 return 0; /* else... */
264 }
265
266
pushline(lua_State * L,int firstline)267 static int pushline (lua_State *L, int firstline) {
268 char buffer[LUA_MAXINPUT];
269 char *b = buffer;
270 size_t l;
271 const char *prmt = get_prompt(L, firstline);
272 int readstatus = lua_readline(L, b, prmt);
273 lua_pop(L, 1); /* remove result from 'get_prompt' */
274 if (readstatus == 0)
275 return 0; /* no input */
276 l = strlen(b);
277 if (l > 0 && b[l-1] == '\n') /* line ends with newline? */
278 b[l-1] = '\0'; /* remove it */
279 if (firstline && b[0] == '=') /* first line starts with `=' ? */
280 lua_pushfstring(L, "return %s", b+1); /* change it to `return' */
281 else
282 lua_pushstring(L, b);
283 lua_freeline(L, b);
284 return 1;
285 }
286
287
loadline(lua_State * L)288 static int loadline (lua_State *L) {
289 int status;
290 lua_settop(L, 0);
291 if (!pushline(L, 1))
292 return -1; /* no input */
293 for (;;) { /* repeat until gets a complete line */
294 size_t l;
295 const char *line = lua_tolstring(L, 1, &l);
296 status = luaL_loadbuffer(L, line, l, "=stdin");
297 if (!incomplete(L, status)) break; /* cannot try to add lines? */
298 if (!pushline(L, 0)) /* no more input? */
299 return -1;
300 lua_pushliteral(L, "\n"); /* add a new line... */
301 lua_insert(L, -2); /* ...between the two lines */
302 lua_concat(L, 3); /* join them */
303 }
304 lua_saveline(L, 1);
305 lua_remove(L, 1); /* remove line */
306 return status;
307 }
308
309
dotty(lua_State * L)310 static void dotty (lua_State *L) {
311 int status;
312 const char *oldprogname = progname;
313 progname = NULL;
314 while ((status = loadline(L)) != -1) {
315 if (status == LUA_OK) status = docall(L, 0, LUA_MULTRET);
316 report(L, status);
317 if (status == LUA_OK && lua_gettop(L) > 0) { /* any result to print? */
318 luaL_checkstack(L, LUA_MINSTACK, "too many results to print");
319 lua_getglobal(L, "print");
320 lua_insert(L, 1);
321 if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != LUA_OK)
322 l_message(progname, lua_pushfstring(L,
323 "error calling " LUA_QL("print") " (%s)",
324 lua_tostring(L, -1)));
325 }
326 }
327 lua_settop(L, 0); /* clear stack */
328 luai_writeline();
329 progname = oldprogname;
330 }
331
332
handle_script(lua_State * L,char ** argv,int n)333 static int handle_script (lua_State *L, char **argv, int n) {
334 int status;
335 const char *fname;
336 int narg = getargs(L, argv, n); /* collect arguments */
337 lua_setglobal(L, "arg");
338 fname = argv[n];
339 if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0)
340 fname = NULL; /* stdin */
341 status = luaL_loadfile(L, fname);
342 lua_insert(L, -(narg+1));
343 if (status == LUA_OK)
344 status = docall(L, narg, LUA_MULTRET);
345 else
346 lua_pop(L, narg);
347 return report(L, status);
348 }
349
350
351 /* check that argument has no extra characters at the end */
352 #define noextrachars(x) {if ((x)[2] != '\0') return -1;}
353
354
355 /* indices of various argument indicators in array args */
356 #define has_i 0 /* -i */
357 #define has_v 1 /* -v */
358 #define has_e 2 /* -e */
359 #define has_E 3 /* -E */
360
361 #define num_has 4 /* number of 'has_*' */
362
363
collectargs(char ** argv,int * args)364 static int collectargs (char **argv, int *args) {
365 int i;
366 for (i = 1; argv[i] != NULL; i++) {
367 if (argv[i][0] != '-') /* not an option? */
368 return i;
369 switch (argv[i][1]) { /* option */
370 case '-':
371 noextrachars(argv[i]);
372 return (argv[i+1] != NULL ? i+1 : 0);
373 case '\0':
374 return i;
375 case 'E':
376 args[has_E] = 1;
377 break;
378 case 'i':
379 noextrachars(argv[i]);
380 args[has_i] = 1; /* go through */
381 case 'v':
382 noextrachars(argv[i]);
383 args[has_v] = 1;
384 break;
385 case 'e':
386 args[has_e] = 1; /* go through */
387 case 'l': /* both options need an argument */
388 if (argv[i][2] == '\0') { /* no concatenated argument? */
389 i++; /* try next 'argv' */
390 if (argv[i] == NULL || argv[i][0] == '-')
391 return -(i - 1); /* no next argument or it is another option */
392 }
393 break;
394 default: /* invalid option; return its index... */
395 return -i; /* ...as a negative value */
396 }
397 }
398 return 0;
399 }
400
401
runargs(lua_State * L,char ** argv,int n)402 static int runargs (lua_State *L, char **argv, int n) {
403 int i;
404 for (i = 1; i < n; i++) {
405 lua_assert(argv[i][0] == '-');
406 switch (argv[i][1]) { /* option */
407 case 'e': {
408 const char *chunk = argv[i] + 2;
409 if (*chunk == '\0') chunk = argv[++i];
410 lua_assert(chunk != NULL);
411 if (dostring(L, chunk, "=(command line)") != LUA_OK)
412 return 0;
413 break;
414 }
415 case 'l': {
416 const char *filename = argv[i] + 2;
417 if (*filename == '\0') filename = argv[++i];
418 lua_assert(filename != NULL);
419 if (dolibrary(L, filename) != LUA_OK)
420 return 0; /* stop if file fails */
421 break;
422 }
423 default: break;
424 }
425 }
426 return 1;
427 }
428
429
handle_luainit(lua_State * L)430 static int handle_luainit (lua_State *L) {
431 const char *name = "=" LUA_INITVERSION;
432 const char *init = getenv(name + 1);
433 if (init == NULL) {
434 name = "=" LUA_INIT;
435 init = getenv(name + 1); /* try alternative name */
436 }
437 if (init == NULL) return LUA_OK;
438 else if (init[0] == '@')
439 return dofile(L, init+1);
440 else
441 return dostring(L, init, name);
442 }
443
444
pmain(lua_State * L)445 static int pmain (lua_State *L) {
446 int argc = (int)lua_tointeger(L, 1);
447 char **argv = (char **)lua_touserdata(L, 2);
448 int script;
449 int args[num_has];
450 args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0;
451 if (argv[0] && argv[0][0]) progname = argv[0];
452 script = collectargs(argv, args);
453 if (script < 0) { /* invalid arg? */
454 print_usage(argv[-script]);
455 return 0;
456 }
457 if (args[has_v]) print_version();
458 if (args[has_E]) { /* option '-E'? */
459 lua_pushboolean(L, 1); /* signal for libraries to ignore env. vars. */
460 lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
461 }
462 /* open standard libraries */
463 luaL_checkversion(L);
464 lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */
465 luaL_openlibs(L); /* open libraries */
466 lua_gc(L, LUA_GCRESTART, 0);
467 if (!args[has_E] && handle_luainit(L) != LUA_OK)
468 return 0; /* error running LUA_INIT */
469 /* execute arguments -e and -l */
470 if (!runargs(L, argv, (script > 0) ? script : argc)) return 0;
471 /* execute main script (if there is one) */
472 if (script && handle_script(L, argv, script) != LUA_OK) return 0;
473 if (args[has_i]) /* -i option? */
474 dotty(L);
475 else if (script == 0 && !args[has_e] && !args[has_v]) { /* no arguments? */
476 if (lua_stdin_is_tty()) {
477 print_version();
478 dotty(L);
479 }
480 else dofile(L, NULL); /* executes stdin as a file */
481 }
482 lua_pushboolean(L, 1); /* signal no errors */
483 return 1;
484 }
485
486
main(int argc,char ** argv)487 int main (int argc, char **argv) {
488 int status, result;
489 lua_State *L = luaL_newstate(); /* create state */
490 if (L == NULL) {
491 l_message(argv[0], "cannot create state: not enough memory");
492 return EXIT_FAILURE;
493 }
494 #ifdef SYSLINUX
495 openconsole(&dev_stdcon_r, &dev_stdcon_w);
496 #endif
497 /* call 'pmain' in protected mode */
498 lua_pushcfunction(L, &pmain);
499 lua_pushinteger(L, argc); /* 1st argument */
500 lua_pushlightuserdata(L, argv); /* 2nd argument */
501 status = lua_pcall(L, 2, 1, 0);
502 result = lua_toboolean(L, -1); /* get result */
503 finalreport(L, status);
504 lua_close(L);
505 return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE;
506 }
507
508