1 /*
2 ** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 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
22 static lua_State *globalL = NULL;
23
24 static const char *progname = LUA_PROGNAME;
25
26
27
lstop(lua_State * L,lua_Debug * ar)28 static void lstop (lua_State *L, lua_Debug *ar) {
29 (void)ar; /* unused arg. */
30 lua_sethook(L, NULL, 0, 0);
31 luaL_error(L, "interrupted!");
32 }
33
34
laction(int i)35 static void laction (int i) {
36 signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
37 terminate process (default action) */
38 lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
39 }
40
41
print_usage(void)42 static void print_usage (void) {
43 fprintf(stderr,
44 "usage: %s [options] [script [args]].\n"
45 "Available options are:\n"
46 " -e stat execute string " LUA_QL("stat") "\n"
47 " -l name require library " LUA_QL("name") "\n"
48 " -i enter interactive mode after executing " LUA_QL("script") "\n"
49 " -v show version information\n"
50 " -- stop handling options\n"
51 " - execute stdin and stop handling options\n"
52 ,
53 progname);
54 fflush(stderr);
55 }
56
57
l_message(const char * pname,const char * msg)58 static void l_message (const char *pname, const char *msg) {
59 if (pname) fprintf(stderr, "%s: ", pname);
60 fprintf(stderr, "%s\n", msg);
61 fflush(stderr);
62 }
63
64
report(lua_State * L,int status)65 static int report (lua_State *L, int status) {
66 if (status && !lua_isnil(L, -1)) {
67 const char *msg = lua_tostring(L, -1);
68 if (msg == NULL) msg = "(error object is not a string)";
69 l_message(progname, msg);
70 lua_pop(L, 1);
71 }
72 return status;
73 }
74
75
traceback(lua_State * L)76 static int traceback (lua_State *L) {
77 if (!lua_isstring(L, 1)) /* 'message' not a string? */
78 return 1; /* keep it intact */
79 lua_getfield(L, LUA_GLOBALSINDEX, "debug");
80 if (!lua_istable(L, -1)) {
81 lua_pop(L, 1);
82 return 1;
83 }
84 lua_getfield(L, -1, "traceback");
85 if (!lua_isfunction(L, -1)) {
86 lua_pop(L, 2);
87 return 1;
88 }
89 lua_pushvalue(L, 1); /* pass error message */
90 lua_pushinteger(L, 2); /* skip this function and traceback */
91 lua_call(L, 2, 1); /* call debug.traceback */
92 return 1;
93 }
94
95
docall(lua_State * L,int narg,int clear)96 static int docall (lua_State *L, int narg, int clear) {
97 int status;
98 int base = lua_gettop(L) - narg; /* function index */
99 lua_pushcfunction(L, traceback); /* push traceback function */
100 lua_insert(L, base); /* put it under chunk and args */
101 signal(SIGINT, laction);
102 status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);
103 signal(SIGINT, SIG_DFL);
104 lua_remove(L, base); /* remove traceback function */
105 /* force a complete garbage collection in case of errors */
106 if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0);
107 return status;
108 }
109
110
print_version(void)111 static void print_version (void) {
112 l_message(NULL, LUA_RELEASE " " LUA_COPYRIGHT);
113 }
114
115
getargs(lua_State * L,char ** argv,int n)116 static int getargs (lua_State *L, char **argv, int n) {
117 int narg;
118 int i;
119 int argc = 0;
120 while (argv[argc]) argc++; /* count total number of arguments */
121 narg = argc - (n + 1); /* number of arguments to the script */
122 luaL_checkstack(L, narg + 3, "too many arguments to script");
123 for (i=n+1; i < argc; i++)
124 lua_pushstring(L, argv[i]);
125 lua_createtable(L, narg, n + 1);
126 for (i=0; i < argc; i++) {
127 lua_pushstring(L, argv[i]);
128 lua_rawseti(L, -2, i - n);
129 }
130 return narg;
131 }
132
133
dofile(lua_State * L,const char * name)134 static int dofile (lua_State *L, const char *name) {
135 int status = luaL_loadfile(L, name) || docall(L, 0, 1);
136 return report(L, status);
137 }
138
139
dostring(lua_State * L,const char * s,const char * name)140 static int dostring (lua_State *L, const char *s, const char *name) {
141 int status = luaL_loadbuffer(L, s, strlen(s), name) || docall(L, 0, 1);
142 return report(L, status);
143 }
144
145
dolibrary(lua_State * L,const char * name)146 static int dolibrary (lua_State *L, const char *name) {
147 lua_getglobal(L, "require");
148 lua_pushstring(L, name);
149 return report(L, docall(L, 1, 1));
150 }
151
152
get_prompt(lua_State * L,int firstline)153 static const char *get_prompt (lua_State *L, int firstline) {
154 const char *p;
155 lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2");
156 p = lua_tostring(L, -1);
157 if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
158 lua_pop(L, 1); /* remove global */
159 return p;
160 }
161
162
incomplete(lua_State * L,int status)163 static int incomplete (lua_State *L, int status) {
164 if (status == LUA_ERRSYNTAX) {
165 size_t lmsg;
166 const char *msg = lua_tolstring(L, -1, &lmsg);
167 const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);
168 if (strstr(msg, LUA_QL("<eof>")) == tp) {
169 lua_pop(L, 1);
170 return 1;
171 }
172 }
173 return 0; /* else... */
174 }
175
176
pushline(lua_State * L,int firstline)177 static int pushline (lua_State *L, int firstline) {
178 char buffer[LUA_MAXINPUT];
179 char *b = buffer;
180 size_t l;
181 const char *prmt = get_prompt(L, firstline);
182 if (lua_readline(L, b, prmt) == 0)
183 return 0; /* no input */
184 l = strlen(b);
185 if (l > 0 && b[l-1] == '\n') /* line ends with newline? */
186 b[l-1] = '\0'; /* remove it */
187 if (firstline && b[0] == '=') /* first line starts with `=' ? */
188 lua_pushfstring(L, "return %s", b+1); /* change it to `return' */
189 else
190 lua_pushstring(L, b);
191 lua_freeline(L, b);
192 return 1;
193 }
194
195
loadline(lua_State * L)196 static int loadline (lua_State *L) {
197 int status;
198 lua_settop(L, 0);
199 if (!pushline(L, 1))
200 return -1; /* no input */
201 for (;;) { /* repeat until gets a complete line */
202 status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin");
203 if (!incomplete(L, status)) break; /* cannot try to add lines? */
204 if (!pushline(L, 0)) /* no more input? */
205 return -1;
206 lua_pushliteral(L, "\n"); /* add a new line... */
207 lua_insert(L, -2); /* ...between the two lines */
208 lua_concat(L, 3); /* join them */
209 }
210 lua_saveline(L, 1);
211 lua_remove(L, 1); /* remove line */
212 return status;
213 }
214
215
dotty(lua_State * L)216 static void dotty (lua_State *L) {
217 int status;
218 const char *oldprogname = progname;
219 progname = NULL;
220 while ((status = loadline(L)) != -1) {
221 if (status == 0) status = docall(L, 0, 0);
222 report(L, status);
223 if (status == 0 && lua_gettop(L) > 0) { /* any result to print? */
224 lua_getglobal(L, "print");
225 lua_insert(L, 1);
226 if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)
227 l_message(progname, lua_pushfstring(L,
228 "error calling " LUA_QL("print") " (%s)",
229 lua_tostring(L, -1)));
230 }
231 }
232 lua_settop(L, 0); /* clear stack */
233 fputs("\n", stdout);
234 fflush(stdout);
235 progname = oldprogname;
236 }
237
238
handle_script(lua_State * L,char ** argv,int n)239 static int handle_script (lua_State *L, char **argv, int n) {
240 int status;
241 const char *fname;
242 int narg = getargs(L, argv, n); /* collect arguments */
243 lua_setglobal(L, "arg");
244 fname = argv[n];
245 if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0)
246 fname = NULL; /* stdin */
247 status = luaL_loadfile(L, fname);
248 lua_insert(L, -(narg+1));
249 if (status == 0)
250 status = docall(L, narg, 0);
251 else
252 lua_pop(L, narg);
253 return report(L, status);
254 }
255
256
257 /* check that argument has no extra characters at the end */
258 #define notail(x) {if ((x)[2] != '\0') return -1;}
259
260
collectargs(char ** argv,int * pi,int * pv,int * pe)261 static int collectargs (char **argv, int *pi, int *pv, int *pe) {
262 int i;
263 for (i = 1; argv[i] != NULL; i++) {
264 if (argv[i][0] != '-') /* not an option? */
265 return i;
266 switch (argv[i][1]) { /* option */
267 case '-':
268 notail(argv[i]);
269 return (argv[i+1] != NULL ? i+1 : 0);
270 case '\0':
271 return i;
272 case 'i':
273 notail(argv[i]);
274 *pi = 1; /* go through */
275 case 'v':
276 notail(argv[i]);
277 *pv = 1;
278 break;
279 case 'e':
280 *pe = 1; /* go through */
281 case 'l':
282 if (argv[i][2] == '\0') {
283 i++;
284 if (argv[i] == NULL) return -1;
285 }
286 break;
287 default: return -1; /* invalid option */
288 }
289 }
290 return 0;
291 }
292
293
runargs(lua_State * L,char ** argv,int n)294 static int runargs (lua_State *L, char **argv, int n) {
295 int i;
296 for (i = 1; i < n; i++) {
297 if (argv[i] == NULL) continue;
298 lua_assert(argv[i][0] == '-');
299 switch (argv[i][1]) { /* option */
300 case 'e': {
301 const char *chunk = argv[i] + 2;
302 if (*chunk == '\0') chunk = argv[++i];
303 lua_assert(chunk != NULL);
304 if (dostring(L, chunk, "=(command line)") != 0)
305 return 1;
306 break;
307 }
308 case 'l': {
309 const char *filename = argv[i] + 2;
310 if (*filename == '\0') filename = argv[++i];
311 lua_assert(filename != NULL);
312 if (dolibrary(L, filename))
313 return 1; /* stop if file fails */
314 break;
315 }
316 default: break;
317 }
318 }
319 return 0;
320 }
321
322
handle_luainit(lua_State * L)323 static int handle_luainit (lua_State *L) {
324 const char *init = getenv(LUA_INIT);
325 if (init == NULL) return 0; /* status OK */
326 else if (init[0] == '@')
327 return dofile(L, init+1);
328 else
329 return dostring(L, init, "=" LUA_INIT);
330 }
331
332
333 struct Smain {
334 int argc;
335 char **argv;
336 int status;
337 };
338
339
pmain(lua_State * L)340 static int pmain (lua_State *L) {
341 struct Smain *s = (struct Smain *)lua_touserdata(L, 1);
342 char **argv = s->argv;
343 int script;
344 int has_i = 0, has_v = 0, has_e = 0;
345 globalL = L;
346 if (argv[0] && argv[0][0]) progname = argv[0];
347 lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */
348 luaL_openlibs(L); /* open libraries */
349 lua_gc(L, LUA_GCRESTART, 0);
350 s->status = handle_luainit(L);
351 if (s->status != 0) return 0;
352 script = collectargs(argv, &has_i, &has_v, &has_e);
353 if (script < 0) { /* invalid args? */
354 print_usage();
355 s->status = 1;
356 return 0;
357 }
358 if (has_v) print_version();
359 s->status = runargs(L, argv, (script > 0) ? script : s->argc);
360 if (s->status != 0) return 0;
361 if (script)
362 s->status = handle_script(L, argv, script);
363 if (s->status != 0) return 0;
364 if (has_i)
365 dotty(L);
366 else if (script == 0 && !has_e && !has_v) {
367 if (lua_stdin_is_tty()) {
368 print_version();
369 dotty(L);
370 }
371 else dofile(L, NULL); /* executes stdin as a file */
372 }
373 return 0;
374 }
375
376
main(int argc,char ** argv)377 int main (int argc, char **argv) {
378 int status;
379 struct Smain s;
380 lua_State *L = lua_open(); /* create state */
381 if (L == NULL) {
382 l_message(argv[0], "cannot create state: not enough memory");
383 return EXIT_FAILURE;
384 }
385 s.argc = argc;
386 s.argv = argv;
387 status = lua_cpcall(L, &pmain, &s);
388 report(L, status);
389 lua_close(L);
390 return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;
391 }
392
393
