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/src/middleware/lua/lstrlib.c

https://bitbucket.org/vivkin/gam3b00bs/
C | 869 lines | 753 code | 95 blank | 21 comment | 185 complexity | dbaf7cf3c47d558cd0235f69116faf39 MD5 | raw file
  1/*
  2** $Id: lstrlib.c,v 1.132.1.4 2008/07/11 17:27:21 roberto Exp $
  3** Standard library for string operations and pattern-matching
  4** See Copyright Notice in lua.h
  5*/
  6
  7
  8#include <ctype.h>
  9#include <stddef.h>
 10#include <stdio.h>
 11#include <stdlib.h>
 12#include <string.h>
 13
 14#define lstrlib_c
 15#define LUA_LIB
 16
 17#include "lua.h"
 18
 19#include "lauxlib.h"
 20#include "lualib.h"
 21
 22
 23/* macro to `unsign' a character */
 24#define uchar(c)        ((unsigned char)(c))
 25
 26
 27
 28static int str_len (lua_State *L) {
 29  size_t l;
 30  luaL_checklstring(L, 1, &l);
 31  lua_pushinteger(L, l);
 32  return 1;
 33}
 34
 35
 36static ptrdiff_t posrelat (ptrdiff_t pos, size_t len) {
 37  /* relative string position: negative means back from end */
 38  if (pos < 0) pos += (ptrdiff_t)len + 1;
 39  return (pos >= 0) ? pos : 0;
 40}
 41
 42
 43static int str_sub (lua_State *L) {
 44  size_t l;
 45  const char *s = luaL_checklstring(L, 1, &l);
 46  ptrdiff_t start = posrelat(luaL_checkinteger(L, 2), l);
 47  ptrdiff_t end = posrelat(luaL_optinteger(L, 3, -1), l);
 48  if (start < 1) start = 1;
 49  if (end > (ptrdiff_t)l) end = (ptrdiff_t)l;
 50  if (start <= end)
 51    lua_pushlstring(L, s+start-1, end-start+1);
 52  else lua_pushliteral(L, "");
 53  return 1;
 54}
 55
 56
 57static int str_reverse (lua_State *L) {
 58  size_t l;
 59  luaL_Buffer b;
 60  const char *s = luaL_checklstring(L, 1, &l);
 61  luaL_buffinit(L, &b);
 62  while (l--) luaL_addchar(&b, s[l]);
 63  luaL_pushresult(&b);
 64  return 1;
 65}
 66
 67
 68static int str_lower (lua_State *L) {
 69  size_t l;
 70  size_t i;
 71  luaL_Buffer b;
 72  const char *s = luaL_checklstring(L, 1, &l);
 73  luaL_buffinit(L, &b);
 74  for (i=0; i<l; i++)
 75    luaL_addchar(&b, tolower(uchar(s[i])));
 76  luaL_pushresult(&b);
 77  return 1;
 78}
 79
 80
 81static int str_upper (lua_State *L) {
 82  size_t l;
 83  size_t i;
 84  luaL_Buffer b;
 85  const char *s = luaL_checklstring(L, 1, &l);
 86  luaL_buffinit(L, &b);
 87  for (i=0; i<l; i++)
 88    luaL_addchar(&b, toupper(uchar(s[i])));
 89  luaL_pushresult(&b);
 90  return 1;
 91}
 92
 93static int str_rep (lua_State *L) {
 94  size_t l;
 95  luaL_Buffer b;
 96  const char *s = luaL_checklstring(L, 1, &l);
 97  int n = luaL_checkint(L, 2);
 98  luaL_buffinit(L, &b);
 99  while (n-- > 0)
100    luaL_addlstring(&b, s, l);
101  luaL_pushresult(&b);
102  return 1;
103}
104
105
106static int str_byte (lua_State *L) {
107  size_t l;
108  const char *s = luaL_checklstring(L, 1, &l);
109  ptrdiff_t posi = posrelat(luaL_optinteger(L, 2, 1), l);
110  ptrdiff_t pose = posrelat(luaL_optinteger(L, 3, posi), l);
111  int n, i;
112  if (posi <= 0) posi = 1;
113  if ((size_t)pose > l) pose = l;
114  if (posi > pose) return 0;  /* empty interval; return no values */
115  n = (int)(pose -  posi + 1);
116  if (posi + n <= pose)  /* overflow? */
117    luaL_error(L, "string slice too long");
118  luaL_checkstack(L, n, "string slice too long");
119  for (i=0; i<n; i++)
120    lua_pushinteger(L, uchar(s[posi+i-1]));
121  return n;
122}
123
124
125static int str_char (lua_State *L) {
126  int n = lua_gettop(L);  /* number of arguments */
127  int i;
128  luaL_Buffer b;
129  luaL_buffinit(L, &b);
130  for (i=1; i<=n; i++) {
131    int c = luaL_checkint(L, i);
132    luaL_argcheck(L, uchar(c) == c, i, "invalid value");
133    luaL_addchar(&b, uchar(c));
134  }
135  luaL_pushresult(&b);
136  return 1;
137}
138
139
140static int writer (lua_State *L, const void* b, size_t size, void* B) {
141  (void)L;
142  luaL_addlstring((luaL_Buffer*) B, (const char *)b, size);
143  return 0;
144}
145
146
147static int str_dump (lua_State *L) {
148  luaL_Buffer b;
149  luaL_checktype(L, 1, LUA_TFUNCTION);
150  lua_settop(L, 1);
151  luaL_buffinit(L,&b);
152  if (lua_dump(L, writer, &b) != 0)
153    luaL_error(L, "unable to dump given function");
154  luaL_pushresult(&b);
155  return 1;
156}
157
158
159
160/*
161** {======================================================
162** PATTERN MATCHING
163** =======================================================
164*/
165
166
167#define CAP_UNFINISHED	(-1)
168#define CAP_POSITION	(-2)
169
170typedef struct MatchState {
171  const char *src_init;  /* init of source string */
172  const char *src_end;  /* end (`\0') of source string */
173  lua_State *L;
174  int level;  /* total number of captures (finished or unfinished) */
175  struct {
176    const char *init;
177    ptrdiff_t len;
178  } capture[LUA_MAXCAPTURES];
179} MatchState;
180
181
182#define L_ESC		'%'
183#define SPECIALS	"^$*+?.([%-"
184
185
186static int check_capture (MatchState *ms, int l) {
187  l -= '1';
188  if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
189    return luaL_error(ms->L, "invalid capture index");
190  return l;
191}
192
193
194static int capture_to_close (MatchState *ms) {
195  int level = ms->level;
196  for (level--; level>=0; level--)
197    if (ms->capture[level].len == CAP_UNFINISHED) return level;
198  return luaL_error(ms->L, "invalid pattern capture");
199}
200
201
202static const char *classend (MatchState *ms, const char *p) {
203  switch (*p++) {
204    case L_ESC: {
205      if (*p == '\0')
206        luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")");
207      return p+1;
208    }
209    case '[': {
210      if (*p == '^') p++;
211      do {  /* look for a `]' */
212        if (*p == '\0')
213          luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")");
214        if (*(p++) == L_ESC && *p != '\0')
215          p++;  /* skip escapes (e.g. `%]') */
216      } while (*p != ']');
217      return p+1;
218    }
219    default: {
220      return p;
221    }
222  }
223}
224
225
226static int match_class (int c, int cl) {
227  int res;
228  switch (tolower(cl)) {
229    case 'a' : res = isalpha(c); break;
230    case 'c' : res = iscntrl(c); break;
231    case 'd' : res = isdigit(c); break;
232    case 'l' : res = islower(c); break;
233    case 'p' : res = ispunct(c); break;
234    case 's' : res = isspace(c); break;
235    case 'u' : res = isupper(c); break;
236    case 'w' : res = isalnum(c); break;
237    case 'x' : res = isxdigit(c); break;
238    case 'z' : res = (c == 0); break;
239    default: return (cl == c);
240  }
241  return (islower(cl) ? res : !res);
242}
243
244
245static int matchbracketclass (int c, const char *p, const char *ec) {
246  int sig = 1;
247  if (*(p+1) == '^') {
248    sig = 0;
249    p++;  /* skip the `^' */
250  }
251  while (++p < ec) {
252    if (*p == L_ESC) {
253      p++;
254      if (match_class(c, uchar(*p)))
255        return sig;
256    }
257    else if ((*(p+1) == '-') && (p+2 < ec)) {
258      p+=2;
259      if (uchar(*(p-2)) <= c && c <= uchar(*p))
260        return sig;
261    }
262    else if (uchar(*p) == c) return sig;
263  }
264  return !sig;
265}
266
267
268static int singlematch (int c, const char *p, const char *ep) {
269  switch (*p) {
270    case '.': return 1;  /* matches any char */
271    case L_ESC: return match_class(c, uchar(*(p+1)));
272    case '[': return matchbracketclass(c, p, ep-1);
273    default:  return (uchar(*p) == c);
274  }
275}
276
277
278static const char *match (MatchState *ms, const char *s, const char *p);
279
280
281static const char *matchbalance (MatchState *ms, const char *s,
282                                   const char *p) {
283  if (*p == 0 || *(p+1) == 0)
284    luaL_error(ms->L, "unbalanced pattern");
285  if (*s != *p) return NULL;
286  else {
287    int b = *p;
288    int e = *(p+1);
289    int cont = 1;
290    while (++s < ms->src_end) {
291      if (*s == e) {
292        if (--cont == 0) return s+1;
293      }
294      else if (*s == b) cont++;
295    }
296  }
297  return NULL;  /* string ends out of balance */
298}
299
300
301static const char *max_expand (MatchState *ms, const char *s,
302                                 const char *p, const char *ep) {
303  ptrdiff_t i = 0;  /* counts maximum expand for item */
304  while ((s+i)<ms->src_end && singlematch(uchar(*(s+i)), p, ep))
305    i++;
306  /* keeps trying to match with the maximum repetitions */
307  while (i>=0) {
308    const char *res = match(ms, (s+i), ep+1);
309    if (res) return res;
310    i--;  /* else didn't match; reduce 1 repetition to try again */
311  }
312  return NULL;
313}
314
315
316static const char *min_expand (MatchState *ms, const char *s,
317                                 const char *p, const char *ep) {
318  for (;;) {
319    const char *res = match(ms, s, ep+1);
320    if (res != NULL)
321      return res;
322    else if (s<ms->src_end && singlematch(uchar(*s), p, ep))
323      s++;  /* try with one more repetition */
324    else return NULL;
325  }
326}
327
328
329static const char *start_capture (MatchState *ms, const char *s,
330                                    const char *p, int what) {
331  const char *res;
332  int level = ms->level;
333  if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures");
334  ms->capture[level].init = s;
335  ms->capture[level].len = what;
336  ms->level = level+1;
337  if ((res=match(ms, s, p)) == NULL)  /* match failed? */
338    ms->level--;  /* undo capture */
339  return res;
340}
341
342
343static const char *end_capture (MatchState *ms, const char *s,
344                                  const char *p) {
345  int l = capture_to_close(ms);
346  const char *res;
347  ms->capture[l].len = s - ms->capture[l].init;  /* close capture */
348  if ((res = match(ms, s, p)) == NULL)  /* match failed? */
349    ms->capture[l].len = CAP_UNFINISHED;  /* undo capture */
350  return res;
351}
352
353
354static const char *match_capture (MatchState *ms, const char *s, int l) {
355  size_t len;
356  l = check_capture(ms, l);
357  len = ms->capture[l].len;
358  if ((size_t)(ms->src_end-s) >= len &&
359      memcmp(ms->capture[l].init, s, len) == 0)
360    return s+len;
361  else return NULL;
362}
363
364
365static const char *match (MatchState *ms, const char *s, const char *p) {
366  init: /* using goto's to optimize tail recursion */
367  switch (*p) {
368    case '(': {  /* start capture */
369      if (*(p+1) == ')')  /* position capture? */
370        return start_capture(ms, s, p+2, CAP_POSITION);
371      else
372        return start_capture(ms, s, p+1, CAP_UNFINISHED);
373    }
374    case ')': {  /* end capture */
375      return end_capture(ms, s, p+1);
376    }
377    case L_ESC: {
378      switch (*(p+1)) {
379        case 'b': {  /* balanced string? */
380          s = matchbalance(ms, s, p+2);
381          if (s == NULL) return NULL;
382          p+=4; goto init;  /* else return match(ms, s, p+4); */
383        }
384        case 'f': {  /* frontier? */
385          const char *ep; char previous;
386          p += 2;
387          if (*p != '[')
388            luaL_error(ms->L, "missing " LUA_QL("[") " after "
389                               LUA_QL("%%f") " in pattern");
390          ep = classend(ms, p);  /* points to what is next */
391          previous = (s == ms->src_init) ? '\0' : *(s-1);
392          if (matchbracketclass(uchar(previous), p, ep-1) ||
393             !matchbracketclass(uchar(*s), p, ep-1)) return NULL;
394          p=ep; goto init;  /* else return match(ms, s, ep); */
395        }
396        default: {
397          if (isdigit(uchar(*(p+1)))) {  /* capture results (%0-%9)? */
398            s = match_capture(ms, s, uchar(*(p+1)));
399            if (s == NULL) return NULL;
400            p+=2; goto init;  /* else return match(ms, s, p+2) */
401          }
402          goto dflt;  /* case default */
403        }
404      }
405    }
406    case '\0': {  /* end of pattern */
407      return s;  /* match succeeded */
408    }
409    case '$': {
410      if (*(p+1) == '\0')  /* is the `$' the last char in pattern? */
411        return (s == ms->src_end) ? s : NULL;  /* check end of string */
412      else goto dflt;
413    }
414    default: dflt: {  /* it is a pattern item */
415      const char *ep = classend(ms, p);  /* points to what is next */
416      int m = s<ms->src_end && singlematch(uchar(*s), p, ep);
417      switch (*ep) {
418        case '?': {  /* optional */
419          const char *res;
420          if (m && ((res=match(ms, s+1, ep+1)) != NULL))
421            return res;
422          p=ep+1; goto init;  /* else return match(ms, s, ep+1); */
423        }
424        case '*': {  /* 0 or more repetitions */
425          return max_expand(ms, s, p, ep);
426        }
427        case '+': {  /* 1 or more repetitions */
428          return (m ? max_expand(ms, s+1, p, ep) : NULL);
429        }
430        case '-': {  /* 0 or more repetitions (minimum) */
431          return min_expand(ms, s, p, ep);
432        }
433        default: {
434          if (!m) return NULL;
435          s++; p=ep; goto init;  /* else return match(ms, s+1, ep); */
436        }
437      }
438    }
439  }
440}
441
442
443
444static const char *lmemfind (const char *s1, size_t l1,
445                               const char *s2, size_t l2) {
446  if (l2 == 0) return s1;  /* empty strings are everywhere */
447  else if (l2 > l1) return NULL;  /* avoids a negative `l1' */
448  else {
449    const char *init;  /* to search for a `*s2' inside `s1' */
450    l2--;  /* 1st char will be checked by `memchr' */
451    l1 = l1-l2;  /* `s2' cannot be found after that */
452    while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) {
453      init++;   /* 1st char is already checked */
454      if (memcmp(init, s2+1, l2) == 0)
455        return init-1;
456      else {  /* correct `l1' and `s1' to try again */
457        l1 -= init-s1;
458        s1 = init;
459      }
460    }
461    return NULL;  /* not found */
462  }
463}
464
465
466static void push_onecapture (MatchState *ms, int i, const char *s,
467                                                    const char *e) {
468  if (i >= ms->level) {
469    if (i == 0)  /* ms->level == 0, too */
470      lua_pushlstring(ms->L, s, e - s);  /* add whole match */
471    else
472      luaL_error(ms->L, "invalid capture index");
473  }
474  else {
475    ptrdiff_t l = ms->capture[i].len;
476    if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");
477    if (l == CAP_POSITION)
478      lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1);
479    else
480      lua_pushlstring(ms->L, ms->capture[i].init, l);
481  }
482}
483
484
485static int push_captures (MatchState *ms, const char *s, const char *e) {
486  int i;
487  int nlevels = (ms->level == 0 && s) ? 1 : ms->level;
488  luaL_checkstack(ms->L, nlevels, "too many captures");
489  for (i = 0; i < nlevels; i++)
490    push_onecapture(ms, i, s, e);
491  return nlevels;  /* number of strings pushed */
492}
493
494
495static int str_find_aux (lua_State *L, int find) {
496  size_t l1, l2;
497  const char *s = luaL_checklstring(L, 1, &l1);
498  const char *p = luaL_checklstring(L, 2, &l2);
499  ptrdiff_t init = posrelat(luaL_optinteger(L, 3, 1), l1) - 1;
500  if (init < 0) init = 0;
501  else if ((size_t)(init) > l1) init = (ptrdiff_t)l1;
502  if (find && (lua_toboolean(L, 4) ||  /* explicit request? */
503      strpbrk(p, SPECIALS) == NULL)) {  /* or no special characters? */
504    /* do a plain search */
505    const char *s2 = lmemfind(s+init, l1-init, p, l2);
506    if (s2) {
507      lua_pushinteger(L, s2-s+1);
508      lua_pushinteger(L, s2-s+l2);
509      return 2;
510    }
511  }
512  else {
513    MatchState ms;
514    int anchor = (*p == '^') ? (p++, 1) : 0;
515    const char *s1=s+init;
516    ms.L = L;
517    ms.src_init = s;
518    ms.src_end = s+l1;
519    do {
520      const char *res;
521      ms.level = 0;
522      if ((res=match(&ms, s1, p)) != NULL) {
523        if (find) {
524          lua_pushinteger(L, s1-s+1);  /* start */
525          lua_pushinteger(L, res-s);   /* end */
526          return push_captures(&ms, NULL, 0) + 2;
527        }
528        else
529          return push_captures(&ms, s1, res);
530      }
531    } while (s1++ < ms.src_end && !anchor);
532  }
533  lua_pushnil(L);  /* not found */
534  return 1;
535}
536
537
538static int str_find (lua_State *L) {
539  return str_find_aux(L, 1);
540}
541
542
543static int str_match (lua_State *L) {
544  return str_find_aux(L, 0);
545}
546
547
548static int gmatch_aux (lua_State *L) {
549  MatchState ms;
550  size_t ls;
551  const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls);
552  const char *p = lua_tostring(L, lua_upvalueindex(2));
553  const char *src;
554  ms.L = L;
555  ms.src_init = s;
556  ms.src_end = s+ls;
557  for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));
558       src <= ms.src_end;
559       src++) {
560    const char *e;
561    ms.level = 0;
562    if ((e = match(&ms, src, p)) != NULL) {
563      lua_Integer newstart = e-s;
564      if (e == src) newstart++;  /* empty match? go at least one position */
565      lua_pushinteger(L, newstart);
566      lua_replace(L, lua_upvalueindex(3));
567      return push_captures(&ms, src, e);
568    }
569  }
570  return 0;  /* not found */
571}
572
573
574static int gmatch (lua_State *L) {
575  luaL_checkstring(L, 1);
576  luaL_checkstring(L, 2);
577  lua_settop(L, 2);
578  lua_pushinteger(L, 0);
579  lua_pushcclosure(L, gmatch_aux, 3);
580  return 1;
581}
582
583
584static int gfind_nodef (lua_State *L) {
585  return luaL_error(L, LUA_QL("string.gfind") " was renamed to "
586                       LUA_QL("string.gmatch"));
587}
588
589
590static void add_s (MatchState *ms, luaL_Buffer *b, const char *s,
591                                                   const char *e) {
592  size_t l, i;
593  const char *news = lua_tolstring(ms->L, 3, &l);
594  for (i = 0; i < l; i++) {
595    if (news[i] != L_ESC)
596      luaL_addchar(b, news[i]);
597    else {
598      i++;  /* skip ESC */
599      if (!isdigit(uchar(news[i])))
600        luaL_addchar(b, news[i]);
601      else if (news[i] == '0')
602          luaL_addlstring(b, s, e - s);
603      else {
604        push_onecapture(ms, news[i] - '1', s, e);
605        luaL_addvalue(b);  /* add capture to accumulated result */
606      }
607    }
608  }
609}
610
611
612static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
613                                                       const char *e) {
614  lua_State *L = ms->L;
615  switch (lua_type(L, 3)) {
616    case LUA_TNUMBER:
617    case LUA_TSTRING: {
618      add_s(ms, b, s, e);
619      return;
620    }
621    case LUA_TFUNCTION: {
622      int n;
623      lua_pushvalue(L, 3);
624      n = push_captures(ms, s, e);
625      lua_call(L, n, 1);
626      break;
627    }
628    case LUA_TTABLE: {
629      push_onecapture(ms, 0, s, e);
630      lua_gettable(L, 3);
631      break;
632    }
633  }
634  if (!lua_toboolean(L, -1)) {  /* nil or false? */
635    lua_pop(L, 1);
636    lua_pushlstring(L, s, e - s);  /* keep original text */
637  }
638  else if (!lua_isstring(L, -1))
639    luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1)); 
640  luaL_addvalue(b);  /* add result to accumulator */
641}
642
643
644static int str_gsub (lua_State *L) {
645  size_t srcl;
646  const char *src = luaL_checklstring(L, 1, &srcl);
647  const char *p = luaL_checkstring(L, 2);
648  int  tr = lua_type(L, 3);
649  int max_s = luaL_optint(L, 4, srcl+1);
650  int anchor = (*p == '^') ? (p++, 1) : 0;
651  int n = 0;
652  MatchState ms;
653  luaL_Buffer b;
654  luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
655                   tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
656                      "string/function/table expected");
657  luaL_buffinit(L, &b);
658  ms.L = L;
659  ms.src_init = src;
660  ms.src_end = src+srcl;
661  while (n < max_s) {
662    const char *e;
663    ms.level = 0;
664    e = match(&ms, src, p);
665    if (e) {
666      n++;
667      add_value(&ms, &b, src, e);
668    }
669    if (e && e>src) /* non empty match? */
670      src = e;  /* skip it */
671    else if (src < ms.src_end)
672      luaL_addchar(&b, *src++);
673    else break;
674    if (anchor) break;
675  }
676  luaL_addlstring(&b, src, ms.src_end-src);
677  luaL_pushresult(&b);
678  lua_pushinteger(L, n);  /* number of substitutions */
679  return 2;
680}
681
682/* }====================================================== */
683
684
685/* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */
686#define MAX_ITEM	512
687/* valid flags in a format specification */
688#define FLAGS	"-+ #0"
689/*
690** maximum size of each format specification (such as '%-099.99d')
691** (+10 accounts for %99.99x plus margin of error)
692*/
693#define MAX_FORMAT	(sizeof(FLAGS) + sizeof(LUA_INTFRMLEN) + 10)
694
695
696static void addquoted (lua_State *L, luaL_Buffer *b, int arg) {
697  size_t l;
698  const char *s = luaL_checklstring(L, arg, &l);
699  luaL_addchar(b, '"');
700  while (l--) {
701    switch (*s) {
702      case '"': case '\\': case '\n': {
703        luaL_addchar(b, '\\');
704        luaL_addchar(b, *s);
705        break;
706      }
707      case '\r': {
708        luaL_addlstring(b, "\\r", 2);
709        break;
710      }
711      case '\0': {
712        luaL_addlstring(b, "\\000", 4);
713        break;
714      }
715      default: {
716        luaL_addchar(b, *s);
717        break;
718      }
719    }
720    s++;
721  }
722  luaL_addchar(b, '"');
723}
724
725static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
726  const char *p = strfrmt;
727  while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++;  /* skip flags */
728  if ((size_t)(p - strfrmt) >= sizeof(FLAGS))
729    luaL_error(L, "invalid format (repeated flags)");
730  if (isdigit(uchar(*p))) p++;  /* skip width */
731  if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
732  if (*p == '.') {
733    p++;
734    if (isdigit(uchar(*p))) p++;  /* skip precision */
735    if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
736  }
737  if (isdigit(uchar(*p)))
738    luaL_error(L, "invalid format (width or precision too long)");
739  *(form++) = '%';
740  strncpy(form, strfrmt, p - strfrmt + 1);
741  form += p - strfrmt + 1;
742  *form = '\0';
743  return p;
744}
745
746
747static void addintlen (char *form) {
748  size_t l = strlen(form);
749  char spec = form[l - 1];
750  strcpy(form + l - 1, LUA_INTFRMLEN);
751  form[l + sizeof(LUA_INTFRMLEN) - 2] = spec;
752  form[l + sizeof(LUA_INTFRMLEN) - 1] = '\0';
753}
754
755
756static int str_format (lua_State *L) {
757  int arg = 1;
758  size_t sfl;
759  const char *strfrmt = luaL_checklstring(L, arg, &sfl);
760  const char *strfrmt_end = strfrmt+sfl;
761  luaL_Buffer b;
762  luaL_buffinit(L, &b);
763  while (strfrmt < strfrmt_end) {
764    if (*strfrmt != L_ESC)
765      luaL_addchar(&b, *strfrmt++);
766    else if (*++strfrmt == L_ESC)
767      luaL_addchar(&b, *strfrmt++);  /* %% */
768    else { /* format item */
769      char form[MAX_FORMAT];  /* to store the format (`%...') */
770      char buff[MAX_ITEM];  /* to store the formatted item */
771      arg++;
772      strfrmt = scanformat(L, strfrmt, form);
773      switch (*strfrmt++) {
774        case 'c': {
775          sprintf(buff, form, (int)luaL_checknumber(L, arg));
776          break;
777        }
778        case 'd':  case 'i': {
779          addintlen(form);
780          sprintf(buff, form, (LUA_INTFRM_T)luaL_checknumber(L, arg));
781          break;
782        }
783        case 'o':  case 'u':  case 'x':  case 'X': {
784          addintlen(form);
785          sprintf(buff, form, (unsigned LUA_INTFRM_T)luaL_checknumber(L, arg));
786          break;
787        }
788        case 'e':  case 'E': case 'f':
789        case 'g': case 'G': {
790          sprintf(buff, form, (double)luaL_checknumber(L, arg));
791          break;
792        }
793        case 'q': {
794          addquoted(L, &b, arg);
795          continue;  /* skip the 'addsize' at the end */
796        }
797        case 's': {
798          size_t l;
799          const char *s = luaL_checklstring(L, arg, &l);
800          if (!strchr(form, '.') && l >= 100) {
801            /* no precision and string is too long to be formatted;
802               keep original string */
803            lua_pushvalue(L, arg);
804            luaL_addvalue(&b);
805            continue;  /* skip the `addsize' at the end */
806          }
807          else {
808            sprintf(buff, form, s);
809            break;
810          }
811        }
812        default: {  /* also treat cases `pnLlh' */
813          return luaL_error(L, "invalid option " LUA_QL("%%%c") " to "
814                               LUA_QL("format"), *(strfrmt - 1));
815        }
816      }
817      luaL_addlstring(&b, buff, strlen(buff));
818    }
819  }
820  luaL_pushresult(&b);
821  return 1;
822}
823
824
825static const luaL_Reg strlib[] = {
826  {"byte", str_byte},
827  {"char", str_char},
828  {"dump", str_dump},
829  {"find", str_find},
830  {"format", str_format},
831  {"gfind", gfind_nodef},
832  {"gmatch", gmatch},
833  {"gsub", str_gsub},
834  {"len", str_len},
835  {"lower", str_lower},
836  {"match", str_match},
837  {"rep", str_rep},
838  {"reverse", str_reverse},
839  {"sub", str_sub},
840  {"upper", str_upper},
841  {NULL, NULL}
842};
843
844
845static void createmetatable (lua_State *L) {
846  lua_createtable(L, 0, 1);  /* create metatable for strings */
847  lua_pushliteral(L, "");  /* dummy string */
848  lua_pushvalue(L, -2);
849  lua_setmetatable(L, -2);  /* set string metatable */
850  lua_pop(L, 1);  /* pop dummy string */
851  lua_pushvalue(L, -2);  /* string library... */
852  lua_setfield(L, -2, "__index");  /* ...is the __index metamethod */
853  lua_pop(L, 1);  /* pop metatable */
854}
855
856
857/*
858** Open string library
859*/
860LUALIB_API int luaopen_string (lua_State *L) {
861  luaL_register(L, LUA_STRLIBNAME, strlib);
862#if defined(LUA_COMPAT_GFIND)
863  lua_getfield(L, -1, "gmatch");
864  lua_setfield(L, -2, "gfind");
865#endif
866  createmetatable(L);
867  return 1;
868}
869