1 /*
2 ** $Id: lstrlib.c,v 1.178.1.1 2013/04/12 18:48:47 roberto Exp $
3 ** Standard library for string operations and pattern-matching
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #define lstrlib_c
9 #define LUA_LIB
10
11 #include <sys/lua/lua.h>
12
13 #include <sys/lua/lauxlib.h>
14 #include <sys/lua/lualib.h>
15
16
17 /*
18 ** maximum number of captures that a pattern can do during
19 ** pattern-matching. This limit is arbitrary.
20 */
21 #if !defined(LUA_MAXCAPTURES)
22 #define LUA_MAXCAPTURES 16
23 #endif
24
25
26 /* macro to `unsign' a character */
27 #define uchar(c) ((unsigned char)(c))
28
29 /*
30 * The provided version of sprintf returns a char *, but str_format expects
31 * it to return the number of characters printed. This version has the expected
32 * behavior.
33 */
str_sprintf(char * buf,const char * fmt,...)34 static size_t str_sprintf(char *buf, const char *fmt, ...) {
35 va_list args;
36 size_t len;
37
38 va_start(args, fmt);
39 len = vsnprintf(buf, INT_MAX, fmt, args);
40 va_end(args);
41
42 return len;
43 }
44
45
str_len(lua_State * L)46 static int str_len (lua_State *L) {
47 size_t l;
48 luaL_checklstring(L, 1, &l);
49 lua_pushinteger(L, (lua_Integer)l);
50 return 1;
51 }
52
53
54 /* translate a relative string position: negative means back from end */
posrelat(ptrdiff_t pos,size_t len)55 static size_t posrelat (ptrdiff_t pos, size_t len) {
56 if (pos >= 0) return (size_t)pos;
57 else if (0u - (size_t)pos > len) return 0;
58 else return len - ((size_t)-pos) + 1;
59 }
60
61
str_sub(lua_State * L)62 static int str_sub (lua_State *L) {
63 size_t l;
64 const char *s = luaL_checklstring(L, 1, &l);
65 size_t start = posrelat(luaL_checkinteger(L, 2), l);
66 size_t end = posrelat(luaL_optinteger(L, 3, -1), l);
67 if (start < 1) start = 1;
68 if (end > l) end = l;
69 if (start <= end)
70 lua_pushlstring(L, s + start - 1, end - start + 1);
71 else lua_pushliteral(L, "");
72 return 1;
73 }
74
75
str_reverse(lua_State * L)76 static int str_reverse (lua_State *L) {
77 size_t l, i;
78 luaL_Buffer b;
79 const char *s = luaL_checklstring(L, 1, &l);
80 char *p = luaL_buffinitsize(L, &b, l);
81 for (i = 0; i < l; i++)
82 p[i] = s[l - i - 1];
83 luaL_pushresultsize(&b, l);
84 return 1;
85 }
86
87
str_lower(lua_State * L)88 static int str_lower (lua_State *L) {
89 size_t l;
90 size_t i;
91 luaL_Buffer b;
92 const char *s = luaL_checklstring(L, 1, &l);
93 char *p = luaL_buffinitsize(L, &b, l);
94 for (i=0; i<l; i++)
95 p[i] = tolower(uchar(s[i]));
96 luaL_pushresultsize(&b, l);
97 return 1;
98 }
99
100
str_upper(lua_State * L)101 static int str_upper (lua_State *L) {
102 size_t l;
103 size_t i;
104 luaL_Buffer b;
105 const char *s = luaL_checklstring(L, 1, &l);
106 char *p = luaL_buffinitsize(L, &b, l);
107 for (i=0; i<l; i++)
108 p[i] = toupper(uchar(s[i]));
109 luaL_pushresultsize(&b, l);
110 return 1;
111 }
112
113
114 /* reasonable limit to avoid arithmetic overflow */
115 #define MAXSIZE ((~(size_t)0) >> 1)
116
str_rep(lua_State * L)117 static int str_rep (lua_State *L) {
118 size_t l, lsep;
119 const char *s = luaL_checklstring(L, 1, &l);
120 int n = luaL_checkint(L, 2);
121 const char *sep = luaL_optlstring(L, 3, "", &lsep);
122 if (n <= 0) lua_pushliteral(L, "");
123 else if (l + lsep < l || l + lsep >= MAXSIZE / n) /* may overflow? */
124 return luaL_error(L, "resulting string too large");
125 else {
126 size_t totallen = n * l + (n - 1) * lsep;
127 luaL_Buffer b;
128 char *p = luaL_buffinitsize(L, &b, totallen);
129 while (n-- > 1) { /* first n-1 copies (followed by separator) */
130 memcpy(p, s, l * sizeof(char)); p += l;
131 if (lsep > 0) { /* avoid empty 'memcpy' (may be expensive) */
132 memcpy(p, sep, lsep * sizeof(char)); p += lsep;
133 }
134 }
135 memcpy(p, s, l * sizeof(char)); /* last copy (not followed by separator) */
136 luaL_pushresultsize(&b, totallen);
137 }
138 return 1;
139 }
140
141
str_byte(lua_State * L)142 static int str_byte (lua_State *L) {
143 size_t l;
144 const char *s = luaL_checklstring(L, 1, &l);
145 size_t posi = posrelat(luaL_optinteger(L, 2, 1), l);
146 size_t pose = posrelat(luaL_optinteger(L, 3, posi), l);
147 int n, i;
148 if (posi < 1) posi = 1;
149 if (pose > l) pose = l;
150 if (posi > pose) return 0; /* empty interval; return no values */
151 n = (int)(pose - posi + 1);
152 if (posi + n <= pose) /* (size_t -> int) overflow? */
153 return luaL_error(L, "string slice too long");
154 luaL_checkstack(L, n, "string slice too long");
155 for (i=0; i<n; i++)
156 lua_pushinteger(L, uchar(s[posi+i-1]));
157 return n;
158 }
159
160
str_char(lua_State * L)161 static int str_char (lua_State *L) {
162 int n = lua_gettop(L); /* number of arguments */
163 int i;
164 luaL_Buffer b;
165 char *p = luaL_buffinitsize(L, &b, n);
166 for (i=1; i<=n; i++) {
167 int c = luaL_checkint(L, i);
168 luaL_argcheck(L, uchar(c) == c, i, "value out of range");
169 p[i - 1] = uchar(c);
170 }
171 luaL_pushresultsize(&b, n);
172 return 1;
173 }
174
175
176 #if defined(LUA_USE_DUMP)
writer(lua_State * L,const void * b,size_t size,void * B)177 static int writer (lua_State *L, const void* b, size_t size, void* B) {
178 (void)L;
179 luaL_addlstring((luaL_Buffer*) B, (const char *)b, size);
180 return 0;
181 }
182
183
str_dump(lua_State * L)184 static int str_dump (lua_State *L) {
185 luaL_Buffer b;
186 luaL_checktype(L, 1, LUA_TFUNCTION);
187 lua_settop(L, 1);
188 luaL_buffinit(L,&b);
189 if (lua_dump(L, writer, &b) != 0)
190 return luaL_error(L, "unable to dump given function");
191 luaL_pushresult(&b);
192 return 1;
193 }
194 #endif
195
196
197 /*
198 ** {======================================================
199 ** PATTERN MATCHING
200 ** =======================================================
201 */
202
203
204 #define CAP_UNFINISHED (-1)
205 #define CAP_POSITION (-2)
206
207
208 typedef struct MatchState {
209 int matchdepth; /* control for recursive depth (to avoid C stack overflow) */
210 const char *src_init; /* init of source string */
211 const char *src_end; /* end ('\0') of source string */
212 const char *p_end; /* end ('\0') of pattern */
213 lua_State *L;
214 int level; /* total number of captures (finished or unfinished) */
215 struct {
216 const char *init;
217 ptrdiff_t len;
218 } capture[LUA_MAXCAPTURES];
219 } MatchState;
220
221
222 /* recursive function */
223 static const char *match (MatchState *ms, const char *s, const char *p);
224
225
226 /* maximum recursion depth for 'match' */
227 #if !defined(MAXCCALLS)
228 #define MAXCCALLS 200
229 #endif
230
231
232 #define L_ESC '%'
233 #define SPECIALS "^$*+?.([%-"
234
235
check_capture(MatchState * ms,int l)236 static int check_capture (MatchState *ms, int l) {
237 l -= '1';
238 if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
239 return luaL_error(ms->L, "invalid capture index %%%d", l + 1);
240 return l;
241 }
242
243
capture_to_close(MatchState * ms)244 static int capture_to_close (MatchState *ms) {
245 int level = ms->level;
246 for (level--; level>=0; level--)
247 if (ms->capture[level].len == CAP_UNFINISHED) return level;
248 return luaL_error(ms->L, "invalid pattern capture");
249 }
250
251
classend(MatchState * ms,const char * p)252 static const char *classend (MatchState *ms, const char *p) {
253 switch (*p++) {
254 case L_ESC: {
255 if (p == ms->p_end)
256 luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")");
257 return p+1;
258 }
259 case '[': {
260 if (*p == '^') p++;
261 do { /* look for a `]' */
262 if (p == ms->p_end)
263 luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")");
264 if (*(p++) == L_ESC && p < ms->p_end)
265 p++; /* skip escapes (e.g. `%]') */
266 } while (*p != ']');
267 return p+1;
268 }
269 default: {
270 return p;
271 }
272 }
273 }
274
275
match_class(int c,int cl)276 static int match_class (int c, int cl) {
277 int res;
278 switch (tolower(cl)) {
279 case 'a' : res = isalpha(c); break;
280 case 'c' : res = iscntrl(c); break;
281 case 'd' : res = isdigit(c); break;
282 case 'g' : res = isgraph(c); break;
283 case 'l' : res = islower(c); break;
284 case 'p' : res = ispunct(c); break;
285 case 's' : res = isspace(c); break;
286 case 'u' : res = isupper(c); break;
287 case 'w' : res = isalnum(c); break;
288 case 'x' : res = isxdigit(c); break;
289 case 'z' : res = (c == 0); break; /* deprecated option */
290 default: return (cl == c);
291 }
292 return (islower(cl) ? res : !res);
293 }
294
295
matchbracketclass(int c,const char * p,const char * ec)296 static int matchbracketclass (int c, const char *p, const char *ec) {
297 int sig = 1;
298 if (*(p+1) == '^') {
299 sig = 0;
300 p++; /* skip the `^' */
301 }
302 while (++p < ec) {
303 if (*p == L_ESC) {
304 p++;
305 if (match_class(c, uchar(*p)))
306 return sig;
307 }
308 else if ((*(p+1) == '-') && (p+2 < ec)) {
309 p+=2;
310 if (uchar(*(p-2)) <= c && c <= uchar(*p))
311 return sig;
312 }
313 else if (uchar(*p) == c) return sig;
314 }
315 return !sig;
316 }
317
318
singlematch(MatchState * ms,const char * s,const char * p,const char * ep)319 static int singlematch (MatchState *ms, const char *s, const char *p,
320 const char *ep) {
321 if (s >= ms->src_end)
322 return 0;
323 else {
324 int c = uchar(*s);
325 switch (*p) {
326 case '.': return 1; /* matches any char */
327 case L_ESC: return match_class(c, uchar(*(p+1)));
328 case '[': return matchbracketclass(c, p, ep-1);
329 default: return (uchar(*p) == c);
330 }
331 }
332 }
333
334
matchbalance(MatchState * ms,const char * s,const char * p)335 static const char *matchbalance (MatchState *ms, const char *s,
336 const char *p) {
337 if (p >= ms->p_end - 1)
338 luaL_error(ms->L, "malformed pattern "
339 "(missing arguments to " LUA_QL("%%b") ")");
340 if (*s != *p) return NULL;
341 else {
342 int b = *p;
343 int e = *(p+1);
344 int cont = 1;
345 while (++s < ms->src_end) {
346 if (*s == e) {
347 if (--cont == 0) return s+1;
348 }
349 else if (*s == b) cont++;
350 }
351 }
352 return NULL; /* string ends out of balance */
353 }
354
355
max_expand(MatchState * ms,const char * s,const char * p,const char * ep)356 static const char *max_expand (MatchState *ms, const char *s,
357 const char *p, const char *ep) {
358 ptrdiff_t i = 0; /* counts maximum expand for item */
359 while (singlematch(ms, s + i, p, ep))
360 i++;
361 /* keeps trying to match with the maximum repetitions */
362 while (i>=0) {
363 const char *res = match(ms, (s+i), ep+1);
364 if (res) return res;
365 i--; /* else didn't match; reduce 1 repetition to try again */
366 }
367 return NULL;
368 }
369
370
min_expand(MatchState * ms,const char * s,const char * p,const char * ep)371 static const char *min_expand (MatchState *ms, const char *s,
372 const char *p, const char *ep) {
373 for (;;) {
374 const char *res = match(ms, s, ep+1);
375 if (res != NULL)
376 return res;
377 else if (singlematch(ms, s, p, ep))
378 s++; /* try with one more repetition */
379 else return NULL;
380 }
381 }
382
383
start_capture(MatchState * ms,const char * s,const char * p,int what)384 static const char *start_capture (MatchState *ms, const char *s,
385 const char *p, int what) {
386 const char *res;
387 int level = ms->level;
388 if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures");
389 ms->capture[level].init = s;
390 ms->capture[level].len = what;
391 ms->level = level+1;
392 if ((res=match(ms, s, p)) == NULL) /* match failed? */
393 ms->level--; /* undo capture */
394 return res;
395 }
396
397
end_capture(MatchState * ms,const char * s,const char * p)398 static const char *end_capture (MatchState *ms, const char *s,
399 const char *p) {
400 int l = capture_to_close(ms);
401 const char *res;
402 ms->capture[l].len = s - ms->capture[l].init; /* close capture */
403 if ((res = match(ms, s, p)) == NULL) /* match failed? */
404 ms->capture[l].len = CAP_UNFINISHED; /* undo capture */
405 return res;
406 }
407
408
match_capture(MatchState * ms,const char * s,int l)409 static const char *match_capture (MatchState *ms, const char *s, int l) {
410 size_t len;
411 l = check_capture(ms, l);
412 len = ms->capture[l].len;
413 if ((size_t)(ms->src_end-s) >= len &&
414 memcmp(ms->capture[l].init, s, len) == 0)
415 return s+len;
416 else return NULL;
417 }
418
419
match(MatchState * ms,const char * s,const char * p)420 static const char *match (MatchState *ms, const char *s, const char *p) {
421 if (ms->matchdepth-- == 0)
422 luaL_error(ms->L, "pattern too complex");
423 init: /* using goto's to optimize tail recursion */
424 if (p != ms->p_end) { /* end of pattern? */
425 switch (*p) {
426 case '(': { /* start capture */
427 if (*(p + 1) == ')') /* position capture? */
428 s = start_capture(ms, s, p + 2, CAP_POSITION);
429 else
430 s = start_capture(ms, s, p + 1, CAP_UNFINISHED);
431 break;
432 }
433 case ')': { /* end capture */
434 s = end_capture(ms, s, p + 1);
435 break;
436 }
437 case '$': {
438 if ((p + 1) != ms->p_end) /* is the `$' the last char in pattern? */
439 goto dflt; /* no; go to default */
440 s = (s == ms->src_end) ? s : NULL; /* check end of string */
441 break;
442 }
443 case L_ESC: { /* escaped sequences not in the format class[*+?-]? */
444 switch (*(p + 1)) {
445 case 'b': { /* balanced string? */
446 s = matchbalance(ms, s, p + 2);
447 if (s != NULL) {
448 p += 4; goto init; /* return match(ms, s, p + 4); */
449 } /* else fail (s == NULL) */
450 break;
451 }
452 case 'f': { /* frontier? */
453 const char *ep; char previous;
454 p += 2;
455 if (*p != '[')
456 luaL_error(ms->L, "missing " LUA_QL("[") " after "
457 LUA_QL("%%f") " in pattern");
458 ep = classend(ms, p); /* points to what is next */
459 previous = (s == ms->src_init) ? '\0' : *(s - 1);
460 if (!matchbracketclass(uchar(previous), p, ep - 1) &&
461 matchbracketclass(uchar(*s), p, ep - 1)) {
462 p = ep; goto init; /* return match(ms, s, ep); */
463 }
464 s = NULL; /* match failed */
465 break;
466 }
467 case '0': case '1': case '2': case '3':
468 case '4': case '5': case '6': case '7':
469 case '8': case '9': { /* capture results (%0-%9)? */
470 s = match_capture(ms, s, uchar(*(p + 1)));
471 if (s != NULL) {
472 p += 2; goto init; /* return match(ms, s, p + 2) */
473 }
474 break;
475 }
476 default: goto dflt;
477 }
478 break;
479 }
480 default: dflt: { /* pattern class plus optional suffix */
481 const char *ep = classend(ms, p); /* points to optional suffix */
482 /* does not match at least once? */
483 if (!singlematch(ms, s, p, ep)) {
484 if (*ep == '*' || *ep == '?' || *ep == '-') { /* accept empty? */
485 p = ep + 1; goto init; /* return match(ms, s, ep + 1); */
486 }
487 else /* '+' or no suffix */
488 s = NULL; /* fail */
489 }
490 else { /* matched once */
491 switch (*ep) { /* handle optional suffix */
492 case '?': { /* optional */
493 const char *res;
494 if ((res = match(ms, s + 1, ep + 1)) != NULL)
495 s = res;
496 else {
497 p = ep + 1; goto init; /* else return match(ms, s, ep + 1); */
498 }
499 break;
500 }
501 case '+': /* 1 or more repetitions */
502 s++; /* 1 match already done */
503 zfs_fallthrough;
504 case '*': /* 0 or more repetitions */
505 s = max_expand(ms, s, p, ep);
506 break;
507 case '-': /* 0 or more repetitions (minimum) */
508 s = min_expand(ms, s, p, ep);
509 break;
510 default: /* no suffix */
511 s++; p = ep; goto init; /* return match(ms, s + 1, ep); */
512 }
513 }
514 break;
515 }
516 }
517 }
518 ms->matchdepth++;
519 return s;
520 }
521
522
523
lmemfind(const char * s1,size_t l1,const char * s2,size_t l2)524 static const char *lmemfind (const char *s1, size_t l1,
525 const char *s2, size_t l2) {
526 if (l2 == 0) return s1; /* empty strings are everywhere */
527 else if (l2 > l1) return NULL; /* avoids a negative `l1' */
528 else {
529 const char *init; /* to search for a `*s2' inside `s1' */
530 l2--; /* 1st char will be checked by `memchr' */
531 l1 = l1-l2; /* `s2' cannot be found after that */
532 while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) {
533 init++; /* 1st char is already checked */
534 if (memcmp(init, s2+1, l2) == 0)
535 return init-1;
536 else { /* correct `l1' and `s1' to try again */
537 l1 -= init-s1;
538 s1 = init;
539 }
540 }
541 return NULL; /* not found */
542 }
543 }
544
545
push_onecapture(MatchState * ms,int i,const char * s,const char * e)546 static void push_onecapture (MatchState *ms, int i, const char *s,
547 const char *e) {
548 if (i >= ms->level) {
549 if (i == 0) /* ms->level == 0, too */
550 lua_pushlstring(ms->L, s, e - s); /* add whole match */
551 else
552 luaL_error(ms->L, "invalid capture index");
553 }
554 else {
555 ptrdiff_t l = ms->capture[i].len;
556 if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");
557 if (l == CAP_POSITION)
558 lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1);
559 else
560 lua_pushlstring(ms->L, ms->capture[i].init, l);
561 }
562 }
563
564
push_captures(MatchState * ms,const char * s,const char * e)565 static int push_captures (MatchState *ms, const char *s, const char *e) {
566 int i;
567 int nlevels = (ms->level == 0 && s) ? 1 : ms->level;
568 luaL_checkstack(ms->L, nlevels, "too many captures");
569 for (i = 0; i < nlevels; i++)
570 push_onecapture(ms, i, s, e);
571 return nlevels; /* number of strings pushed */
572 }
573
574
575 /* check whether pattern has no special characters */
nospecials(const char * p,size_t l)576 static int nospecials (const char *p, size_t l) {
577 size_t upto = 0;
578 do {
579 if (strpbrk(p + upto, SPECIALS))
580 return 0; /* pattern has a special character */
581 upto += strlen(p + upto) + 1; /* may have more after \0 */
582 } while (upto <= l);
583 return 1; /* no special chars found */
584 }
585
586
str_find_aux(lua_State * L,int find)587 static int str_find_aux (lua_State *L, int find) {
588 size_t ls, lp;
589 const char *s = luaL_checklstring(L, 1, &ls);
590 const char *p = luaL_checklstring(L, 2, &lp);
591 size_t init = posrelat(luaL_optinteger(L, 3, 1), ls);
592 if (init < 1) init = 1;
593 else if (init > ls + 1) { /* start after string's end? */
594 lua_pushnil(L); /* cannot find anything */
595 return 1;
596 }
597 /* explicit request or no special characters? */
598 if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) {
599 /* do a plain search */
600 const char *s2 = lmemfind(s + init - 1, ls - init + 1, p, lp);
601 if (s2) {
602 lua_pushinteger(L, s2 - s + 1);
603 lua_pushinteger(L, s2 - s + lp);
604 return 2;
605 }
606 }
607 else {
608 MatchState ms;
609 const char *s1 = s + init - 1;
610 int anchor = (*p == '^');
611 if (anchor) {
612 p++; lp--; /* skip anchor character */
613 }
614 ms.L = L;
615 ms.matchdepth = MAXCCALLS;
616 ms.src_init = s;
617 ms.src_end = s + ls;
618 ms.p_end = p + lp;
619 do {
620 const char *res;
621 ms.level = 0;
622 lua_assert(ms.matchdepth == MAXCCALLS);
623 if ((res=match(&ms, s1, p)) != NULL) {
624 if (find) {
625 lua_pushinteger(L, s1 - s + 1); /* start */
626 lua_pushinteger(L, res - s); /* end */
627 return push_captures(&ms, NULL, 0) + 2;
628 }
629 else
630 return push_captures(&ms, s1, res);
631 }
632 } while (s1++ < ms.src_end && !anchor);
633 }
634 lua_pushnil(L); /* not found */
635 return 1;
636 }
637
638
str_find(lua_State * L)639 static int str_find (lua_State *L) {
640 return str_find_aux(L, 1);
641 }
642
643
str_match(lua_State * L)644 static int str_match (lua_State *L) {
645 return str_find_aux(L, 0);
646 }
647
648
gmatch_aux(lua_State * L)649 static int gmatch_aux (lua_State *L) {
650 MatchState ms;
651 size_t ls, lp;
652 const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls);
653 const char *p = lua_tolstring(L, lua_upvalueindex(2), &lp);
654 const char *src;
655 ms.L = L;
656 ms.matchdepth = MAXCCALLS;
657 ms.src_init = s;
658 ms.src_end = s+ls;
659 ms.p_end = p + lp;
660 for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));
661 src <= ms.src_end;
662 src++) {
663 const char *e;
664 ms.level = 0;
665 lua_assert(ms.matchdepth == MAXCCALLS);
666 if ((e = match(&ms, src, p)) != NULL) {
667 lua_Integer newstart = e-s;
668 if (e == src) newstart++; /* empty match? go at least one position */
669 lua_pushinteger(L, newstart);
670 lua_replace(L, lua_upvalueindex(3));
671 return push_captures(&ms, src, e);
672 }
673 }
674 return 0; /* not found */
675 }
676
677
str_gmatch(lua_State * L)678 static int str_gmatch (lua_State *L) {
679 luaL_checkstring(L, 1);
680 luaL_checkstring(L, 2);
681 lua_settop(L, 2);
682 lua_pushinteger(L, 0);
683 lua_pushcclosure(L, gmatch_aux, 3);
684 return 1;
685 }
686
687
add_s(MatchState * ms,luaL_Buffer * b,const char * s,const char * e)688 static void add_s (MatchState *ms, luaL_Buffer *b, const char *s,
689 const char *e) {
690 size_t l, i;
691 const char *news = lua_tolstring(ms->L, 3, &l);
692 for (i = 0; i < l; i++) {
693 if (news[i] != L_ESC)
694 luaL_addchar(b, news[i]);
695 else {
696 i++; /* skip ESC */
697 if (!isdigit(uchar(news[i]))) {
698 if (news[i] != L_ESC)
699 luaL_error(ms->L, "invalid use of " LUA_QL("%c")
700 " in replacement string", L_ESC);
701 luaL_addchar(b, news[i]);
702 }
703 else if (news[i] == '0')
704 luaL_addlstring(b, s, e - s);
705 else {
706 push_onecapture(ms, news[i] - '1', s, e);
707 luaL_addvalue(b); /* add capture to accumulated result */
708 }
709 }
710 }
711 }
712
713
add_value(MatchState * ms,luaL_Buffer * b,const char * s,const char * e,int tr)714 static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
715 const char *e, int tr) {
716 lua_State *L = ms->L;
717 switch (tr) {
718 case LUA_TFUNCTION: {
719 int n;
720 lua_pushvalue(L, 3);
721 n = push_captures(ms, s, e);
722 lua_call(L, n, 1);
723 break;
724 }
725 case LUA_TTABLE: {
726 push_onecapture(ms, 0, s, e);
727 lua_gettable(L, 3);
728 break;
729 }
730 default: { /* LUA_TNUMBER or LUA_TSTRING */
731 add_s(ms, b, s, e);
732 return;
733 }
734 }
735 if (!lua_toboolean(L, -1)) { /* nil or false? */
736 lua_pop(L, 1);
737 lua_pushlstring(L, s, e - s); /* keep original text */
738 }
739 else if (!lua_isstring(L, -1))
740 luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1));
741 luaL_addvalue(b); /* add result to accumulator */
742 }
743
744
str_gsub(lua_State * L)745 static int str_gsub (lua_State *L) {
746 size_t srcl, lp;
747 const char *src = luaL_checklstring(L, 1, &srcl);
748 const char *p = luaL_checklstring(L, 2, &lp);
749 int tr = lua_type(L, 3);
750 size_t max_s = luaL_optinteger(L, 4, srcl+1);
751 int anchor = (*p == '^');
752 size_t n = 0;
753 MatchState ms;
754 luaL_Buffer b;
755 luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
756 tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
757 "string/function/table expected");
758 luaL_buffinit(L, &b);
759 if (anchor) {
760 p++; lp--; /* skip anchor character */
761 }
762 ms.L = L;
763 ms.matchdepth = MAXCCALLS;
764 ms.src_init = src;
765 ms.src_end = src+srcl;
766 ms.p_end = p + lp;
767 while (n < max_s) {
768 const char *e;
769 ms.level = 0;
770 lua_assert(ms.matchdepth == MAXCCALLS);
771 e = match(&ms, src, p);
772 if (e) {
773 n++;
774 add_value(&ms, &b, src, e, tr);
775 }
776 if (e && e>src) /* non empty match? */
777 src = e; /* skip it */
778 else if (src < ms.src_end)
779 luaL_addchar(&b, *src++);
780 else break;
781 if (anchor) break;
782 }
783 luaL_addlstring(&b, src, ms.src_end-src);
784 luaL_pushresult(&b);
785 lua_pushinteger(L, n); /* number of substitutions */
786 return 2;
787 }
788
789 /* }====================================================== */
790
791
792
793 /*
794 ** {======================================================
795 ** STRING FORMAT
796 ** =======================================================
797 */
798
799 /*
800 ** LUA_INTFRMLEN is the length modifier for integer conversions in
801 ** 'string.format'; LUA_INTFRM_T is the integer type corresponding to
802 ** the previous length
803 */
804 #if !defined(LUA_INTFRMLEN) /* { */
805 #if defined(LUA_USE_LONGLONG)
806
807 #define LUA_INTFRMLEN "ll"
808 #define LUA_INTFRM_T long long
809
810 #else
811
812 #define LUA_INTFRMLEN "l"
813 #define LUA_INTFRM_T long
814
815 #endif
816 #endif /* } */
817
818
819 /*
820 ** LUA_FLTFRMLEN is the length modifier for float conversions in
821 ** 'string.format'; LUA_FLTFRM_T is the float type corresponding to
822 ** the previous length
823 */
824 #if !defined(LUA_FLTFRMLEN)
825
826 #define LUA_FLTFRMLEN ""
827 #define LUA_FLTFRM_T double
828
829 #endif
830
831
832 /* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */
833 #define MAX_ITEM 512
834 /* valid flags in a format specification */
835 #define FLAGS "-+ #0"
836 /*
837 ** maximum size of each format specification (such as '%-099.99d')
838 ** (+10 accounts for %99.99x plus margin of error)
839 */
840 #define MAX_FORMAT (sizeof(FLAGS) + sizeof(LUA_INTFRMLEN) + 10)
841
842
addquoted(lua_State * L,luaL_Buffer * b,int arg)843 static void addquoted (lua_State *L, luaL_Buffer *b, int arg) {
844 size_t l;
845 const char *s = luaL_checklstring(L, arg, &l);
846 luaL_addchar(b, '"');
847 while (l--) {
848 if (*s == '"' || *s == '\\' || *s == '\n') {
849 luaL_addchar(b, '\\');
850 luaL_addchar(b, *s);
851 }
852 else if (*s == '\0' || iscntrl(uchar(*s))) {
853 char buff[10];
854 if (!isdigit(uchar(*(s+1))))
855 snprintf(buff, sizeof(buff), "\\%d", (int)uchar(*s));
856 else
857 snprintf(buff, sizeof(buff), "\\%03d", (int)uchar(*s));
858 luaL_addstring(b, buff);
859 }
860 else
861 luaL_addchar(b, *s);
862 s++;
863 }
864 luaL_addchar(b, '"');
865 }
866
scanformat(lua_State * L,const char * strfrmt,char * form)867 static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
868 const char *p = strfrmt;
869 while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++; /* skip flags */
870 if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char))
871 luaL_error(L, "invalid format (repeated flags)");
872 if (isdigit(uchar(*p))) p++; /* skip width */
873 if (isdigit(uchar(*p))) p++; /* (2 digits at most) */
874 if (*p == '.') {
875 p++;
876 if (isdigit(uchar(*p))) p++; /* skip precision */
877 if (isdigit(uchar(*p))) p++; /* (2 digits at most) */
878 }
879 if (isdigit(uchar(*p)))
880 luaL_error(L, "invalid format (width or precision too long)");
881 *(form++) = '%';
882 memcpy(form, strfrmt, (p - strfrmt + 1) * sizeof(char));
883 form += p - strfrmt + 1;
884 *form = '\0';
885 return p;
886 }
887
888
889 /*
890 ** add length modifier into formats
891 */
addlenmod(char * form,const char * lenmod,size_t size)892 static void addlenmod (char *form, const char *lenmod, size_t size) {
893 size_t l = strlen(form);
894 size_t lm = strlen(lenmod);
895 char spec = form[l - 1];
896 strlcpy(form + l - 1, lenmod, size - (l - 1));
897 form[l + lm - 1] = spec;
898 form[l + lm] = '\0';
899 }
900
901
str_format(lua_State * L)902 static int str_format (lua_State *L) {
903 int top = lua_gettop(L);
904 int arg = 1;
905 size_t sfl;
906 const char *strfrmt = luaL_checklstring(L, arg, &sfl);
907 const char *strfrmt_end = strfrmt+sfl;
908 luaL_Buffer b;
909 luaL_buffinit(L, &b);
910 while (strfrmt < strfrmt_end) {
911 if (*strfrmt != L_ESC)
912 luaL_addchar(&b, *strfrmt++);
913 else if (*++strfrmt == L_ESC)
914 luaL_addchar(&b, *strfrmt++); /* %% */
915 else { /* format item */
916 char form[MAX_FORMAT]; /* to store the format (`%...') */
917 char *buff = luaL_prepbuffsize(&b, MAX_ITEM); /* to put formatted item */
918 int nb = 0; /* number of bytes in added item */
919 if (++arg > top)
920 luaL_argerror(L, arg, "no value");
921 strfrmt = scanformat(L, strfrmt, form);
922 switch (*strfrmt++) {
923 case 'c': {
924 nb = str_sprintf(buff, form, luaL_checkint(L, arg));
925 break;
926 }
927 case 'd': case 'i': {
928 lua_Number n = luaL_checknumber(L, arg);
929 LUA_INTFRM_T ni = (LUA_INTFRM_T)n;
930 lua_Number diff = n - (lua_Number)ni;
931 luaL_argcheck(L, -1 < diff && diff < 1, arg,
932 "not a number in proper range");
933 addlenmod(form, LUA_INTFRMLEN, MAX_FORMAT);
934 nb = str_sprintf(buff, form, ni);
935 break;
936 }
937 case 'o': case 'u': case 'x': case 'X': {
938 lua_Number n = luaL_checknumber(L, arg);
939 unsigned LUA_INTFRM_T ni = (unsigned LUA_INTFRM_T)n;
940 lua_Number diff = n - (lua_Number)ni;
941 luaL_argcheck(L, -1 < diff && diff < 1, arg,
942 "not a non-negative number in proper range");
943 addlenmod(form, LUA_INTFRMLEN, MAX_FORMAT);
944 nb = str_sprintf(buff, form, ni);
945 break;
946 }
947 #if defined(LUA_USE_FLOAT_FORMATS)
948 case 'e': case 'E': case 'f':
949 #if defined(LUA_USE_AFORMAT)
950 case 'a': case 'A':
951 #endif
952 case 'g': case 'G': {
953 addlenmod(form, LUA_FLTFRMLEN, MAX_FORMAT);
954 nb = str_sprintf(buff, form, (LUA_FLTFRM_T)luaL_checknumber(L, arg));
955 break;
956 }
957 #endif
958 case 'q': {
959 addquoted(L, &b, arg);
960 break;
961 }
962 case 's': {
963 size_t l;
964 const char *s = luaL_tolstring(L, arg, &l);
965 if (!strchr(form, '.') && l >= 100) {
966 /* no precision and string is too long to be formatted;
967 keep original string */
968 luaL_addvalue(&b);
969 break;
970 }
971 else {
972 nb = str_sprintf(buff, form, s);
973 lua_pop(L, 1); /* remove result from 'luaL_tolstring' */
974 break;
975 }
976 }
977 default: { /* also treat cases `pnLlh' */
978 return luaL_error(L, "invalid option " LUA_QL("%%%c") " to "
979 LUA_QL("format"), *(strfrmt - 1));
980 }
981 }
982 luaL_addsize(&b, nb);
983 }
984 }
985 luaL_pushresult(&b);
986 return 1;
987 }
988
989 /* }====================================================== */
990
991
992 static const luaL_Reg strlib[] = {
993 {"byte", str_byte},
994 {"char", str_char},
995 #if defined(LUA_USE_DUMP)
996 {"dump", str_dump},
997 #endif
998 {"find", str_find},
999 {"format", str_format},
1000 {"gmatch", str_gmatch},
1001 {"gsub", str_gsub},
1002 {"len", str_len},
1003 {"lower", str_lower},
1004 {"match", str_match},
1005 {"rep", str_rep},
1006 {"reverse", str_reverse},
1007 {"sub", str_sub},
1008 {"upper", str_upper},
1009 {NULL, NULL}
1010 };
1011
1012
createmetatable(lua_State * L)1013 static void createmetatable (lua_State *L) {
1014 lua_createtable(L, 0, 1); /* table to be metatable for strings */
1015 lua_pushliteral(L, ""); /* dummy string */
1016 lua_pushvalue(L, -2); /* copy table */
1017 lua_setmetatable(L, -2); /* set table as metatable for strings */
1018 lua_pop(L, 1); /* pop dummy string */
1019 lua_pushvalue(L, -2); /* get string library */
1020 lua_setfield(L, -2, "__index"); /* metatable.__index = string */
1021 lua_pop(L, 1); /* pop metatable */
1022 }
1023
1024
1025 /*
1026 ** Open string library
1027 */
luaopen_string(lua_State * L)1028 LUAMOD_API int luaopen_string (lua_State *L) {
1029 luaL_newlib(L, strlib);
1030 createmetatable(L);
1031 return 1;
1032 }
1033
1034 #if defined(_KERNEL)
1035
1036 EXPORT_SYMBOL(luaopen_string);
1037
1038 #endif
1039