/* ** $Id: lstrlib.c,v 1.178.1.1 2013/04/12 18:48:47 roberto Exp $ ** Standard library for string operations and pattern-matching ** See Copyright Notice in lua.h */ #include #include #define lstrlib_c #define LUA_LIB #include "lua.h" #include "lauxlib.h" #include "lualib.h" /* ** maximum number of captures that a pattern can do during ** pattern-matching. This limit is arbitrary. */ #if !defined(LUA_MAXCAPTURES) #define LUA_MAXCAPTURES 32 #endif /* macro to `unsign' a character */ #define uchar(c) ((unsigned char)(c)) /* * PATCHED: add missing character macros. */ #define tolower(C) (((C) >= 'A' && (C) <= 'Z') ? (C) - 'A' + 'a' : (C)) #define toupper(C) (((C) >= 'a' && (C) <= 'z') ? (C) - 'a' + 'A': (C)) #define isgraph(C) ((C) >= 0x21 && (C) <= 0x7E) #define ispunct(C) (((C) >= 0x21 && (C) <= 0x2F) || \ ((C) >= 0x3A && (C) <= 0x40) || \ ((C) >= 0x5B && (C) <= 0x60) || \ ((C) >= 0x7B && (C) <= 0x7E)) /* * The provided version of sprintf returns a char *, but str_format expects * it to return the number of characters printed. This version has the expected * behavior. */ static size_t str_sprintf(char *buf, const char *fmt, ...) { va_list args; size_t len; va_start(args, fmt); len = vsnprintf(buf, INT_MAX, fmt, args); va_end(args); return len; } static int str_len (lua_State *L) { size_t l; luaL_checklstring(L, 1, &l); lua_pushinteger(L, (lua_Integer)l); return 1; } /* translate a relative string position: negative means back from end */ static size_t posrelat (ptrdiff_t pos, size_t len) { if (pos >= 0) return (size_t)pos; else if (0u - (size_t)pos > len) return 0; else return len - ((size_t)-pos) + 1; } static int str_sub (lua_State *L) { size_t l; const char *s = luaL_checklstring(L, 1, &l); size_t start = posrelat(luaL_checkinteger(L, 2), l); size_t end = posrelat(luaL_optinteger(L, 3, -1), l); if (start < 1) start = 1; if (end > l) end = l; if (start <= end) lua_pushlstring(L, s + start - 1, end - start + 1); else lua_pushliteral(L, ""); return 1; } static int str_reverse (lua_State *L) { size_t l, i; luaL_Buffer b; const char *s = luaL_checklstring(L, 1, &l); char *p = luaL_buffinitsize(L, &b, l); for (i = 0; i < l; i++) p[i] = s[l - i - 1]; luaL_pushresultsize(&b, l); return 1; } static int str_lower (lua_State *L) { size_t l; size_t i; luaL_Buffer b; const char *s = luaL_checklstring(L, 1, &l); char *p = luaL_buffinitsize(L, &b, l); for (i=0; i> 1) static int str_rep (lua_State *L) { size_t l, lsep; const char *s = luaL_checklstring(L, 1, &l); int n = luaL_checkint(L, 2); const char *sep = luaL_optlstring(L, 3, "", &lsep); if (n <= 0) lua_pushliteral(L, ""); else if (l + lsep < l || l + lsep >= MAXSIZE / n) /* may overflow? */ return luaL_error(L, "resulting string too large"); else { size_t totallen = n * l + (n - 1) * lsep; luaL_Buffer b; char *p = luaL_buffinitsize(L, &b, totallen); while (n-- > 1) { /* first n-1 copies (followed by separator) */ memcpy(p, s, l * sizeof(char)); p += l; if (lsep > 0) { /* avoid empty 'memcpy' (may be expensive) */ memcpy(p, sep, lsep * sizeof(char)); p += lsep; } } memcpy(p, s, l * sizeof(char)); /* last copy (not followed by separator) */ luaL_pushresultsize(&b, totallen); } return 1; } static int str_byte (lua_State *L) { size_t l; const char *s = luaL_checklstring(L, 1, &l); size_t posi = posrelat(luaL_optinteger(L, 2, 1), l); size_t pose = posrelat(luaL_optinteger(L, 3, posi), l); int n, i; if (posi < 1) posi = 1; if (pose > l) pose = l; if (posi > pose) return 0; /* empty interval; return no values */ n = (int)(pose - posi + 1); if (posi + n <= pose) /* (size_t -> int) overflow? */ return luaL_error(L, "string slice too long"); luaL_checkstack(L, n, "string slice too long"); for (i=0; i= ms->level || ms->capture[l].len == CAP_UNFINISHED) return luaL_error(ms->L, "invalid capture index %%%d", l + 1); return l; } static int capture_to_close (MatchState *ms) { int level = ms->level; for (level--; level>=0; level--) if (ms->capture[level].len == CAP_UNFINISHED) return level; return luaL_error(ms->L, "invalid pattern capture"); } static const char *classend (MatchState *ms, const char *p) { switch (*p++) { case L_ESC: { if (p == ms->p_end) luaL_error(ms->L, "malformed pattern (ends with " LUA_QL("%%") ")"); return p+1; } case '[': { if (*p == '^') p++; do { /* look for a `]' */ if (p == ms->p_end) luaL_error(ms->L, "malformed pattern (missing " LUA_QL("]") ")"); if (*(p++) == L_ESC && p < ms->p_end) p++; /* skip escapes (e.g. `%]') */ } while (*p != ']'); return p+1; } default: { return p; } } } static int iscntrl(int c) { return ((c < 0x20) || (c == 0x7f)); } static int match_class (int c, int cl) { int res; switch (tolower(cl)) { case 'a' : res = isalpha(c); break; case 'c' : res = iscntrl(c); break; case 'd' : res = isdigit(c); break; case 'g' : res = isgraph(c); break; case 'l' : res = islower(c); break; case 'p' : res = ispunct(c); break; case 's' : res = isspace(c); break; case 'u' : res = isupper(c); break; case 'w' : res = isalnum(c); break; case 'x' : res = isxdigit(c); break; case 'z' : res = (c == 0); break; /* deprecated option */ default: return (cl == c); } return (islower(cl) ? res : !res); } static int matchbracketclass (int c, const char *p, const char *ec) { int sig = 1; if (*(p+1) == '^') { sig = 0; p++; /* skip the `^' */ } while (++p < ec) { if (*p == L_ESC) { p++; if (match_class(c, uchar(*p))) return sig; } else if ((*(p+1) == '-') && (p+2 < ec)) { p+=2; if (uchar(*(p-2)) <= c && c <= uchar(*p)) return sig; } else if (uchar(*p) == c) return sig; } return !sig; } static int singlematch (MatchState *ms, const char *s, const char *p, const char *ep) { if (s >= ms->src_end) return 0; else { int c = uchar(*s); switch (*p) { case '.': return 1; /* matches any char */ case L_ESC: return match_class(c, uchar(*(p+1))); case '[': return matchbracketclass(c, p, ep-1); default: return (uchar(*p) == c); } } } static const char *matchbalance (MatchState *ms, const char *s, const char *p) { if (p >= ms->p_end - 1) luaL_error(ms->L, "malformed pattern " "(missing arguments to " LUA_QL("%%b") ")"); if (*s != *p) return NULL; else { int b = *p; int e = *(p+1); int cont = 1; while (++s < ms->src_end) { if (*s == e) { if (--cont == 0) return s+1; } else if (*s == b) cont++; } } return NULL; /* string ends out of balance */ } static const char *max_expand (MatchState *ms, const char *s, const char *p, const char *ep) { ptrdiff_t i = 0; /* counts maximum expand for item */ while (singlematch(ms, s + i, p, ep)) i++; /* keeps trying to match with the maximum repetitions */ while (i>=0) { const char *res = match(ms, (s+i), ep+1); if (res) return res; i--; /* else didn't match; reduce 1 repetition to try again */ } return NULL; } static const char *min_expand (MatchState *ms, const char *s, const char *p, const char *ep) { for (;;) { const char *res = match(ms, s, ep+1); if (res != NULL) return res; else if (singlematch(ms, s, p, ep)) s++; /* try with one more repetition */ else return NULL; } } static const char *start_capture (MatchState *ms, const char *s, const char *p, int what) { const char *res; int level = ms->level; if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures"); ms->capture[level].init = s; ms->capture[level].len = what; ms->level = level+1; if ((res=match(ms, s, p)) == NULL) /* match failed? */ ms->level--; /* undo capture */ return res; } static const char *end_capture (MatchState *ms, const char *s, const char *p) { int l = capture_to_close(ms); const char *res; ms->capture[l].len = s - ms->capture[l].init; /* close capture */ if ((res = match(ms, s, p)) == NULL) /* match failed? */ ms->capture[l].len = CAP_UNFINISHED; /* undo capture */ return res; } static const char *match_capture (MatchState *ms, const char *s, int l) { size_t len; l = check_capture(ms, l); len = ms->capture[l].len; if ((size_t)(ms->src_end-s) >= len && memcmp(ms->capture[l].init, s, len) == 0) return s+len; else return NULL; } static const char *match (MatchState *ms, const char *s, const char *p) { if (ms->matchdepth-- == 0) luaL_error(ms->L, "pattern too complex"); init: /* using goto's to optimize tail recursion */ if (p != ms->p_end) { /* end of pattern? */ switch (*p) { case '(': { /* start capture */ if (*(p + 1) == ')') /* position capture? */ s = start_capture(ms, s, p + 2, CAP_POSITION); else s = start_capture(ms, s, p + 1, CAP_UNFINISHED); break; } case ')': { /* end capture */ s = end_capture(ms, s, p + 1); break; } case '$': { if ((p + 1) != ms->p_end) /* is the `$' the last char in pattern? */ goto dflt; /* no; go to default */ s = (s == ms->src_end) ? s : NULL; /* check end of string */ break; } case L_ESC: { /* escaped sequences not in the format class[*+?-]? */ switch (*(p + 1)) { case 'b': { /* balanced string? */ s = matchbalance(ms, s, p + 2); if (s != NULL) { p += 4; goto init; /* return match(ms, s, p + 4); */ } /* else fail (s == NULL) */ break; } case 'f': { /* frontier? */ const char *ep; char previous; p += 2; if (*p != '[') luaL_error(ms->L, "missing " LUA_QL("[") " after " LUA_QL("%%f") " in pattern"); ep = classend(ms, p); /* points to what is next */ previous = (s == ms->src_init) ? '\0' : *(s - 1); if (!matchbracketclass(uchar(previous), p, ep - 1) && matchbracketclass(uchar(*s), p, ep - 1)) { p = ep; goto init; /* return match(ms, s, ep); */ } s = NULL; /* match failed */ break; } case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': { /* capture results (%0-%9)? */ s = match_capture(ms, s, uchar(*(p + 1))); if (s != NULL) { p += 2; goto init; /* return match(ms, s, p + 2) */ } break; } default: goto dflt; } break; } default: dflt: { /* pattern class plus optional suffix */ const char *ep = classend(ms, p); /* points to optional suffix */ /* does not match at least once? */ if (!singlematch(ms, s, p, ep)) { if (*ep == '*' || *ep == '?' || *ep == '-') { /* accept empty? */ p = ep + 1; goto init; /* return match(ms, s, ep + 1); */ } else /* '+' or no suffix */ s = NULL; /* fail */ } else { /* matched once */ switch (*ep) { /* handle optional suffix */ case '?': { /* optional */ const char *res; if ((res = match(ms, s + 1, ep + 1)) != NULL) s = res; else { p = ep + 1; goto init; /* else return match(ms, s, ep + 1); */ } break; } case '+': /* 1 or more repetitions */ s++; /* 1 match already done */ /* FALLTHROUGH */ case '*': /* 0 or more repetitions */ s = max_expand(ms, s, p, ep); break; case '-': /* 0 or more repetitions (minimum) */ s = min_expand(ms, s, p, ep); break; default: /* no suffix */ s++; p = ep; goto init; /* return match(ms, s + 1, ep); */ } } break; } } } ms->matchdepth++; return s; } static const char *lmemfind (const char *s1, size_t l1, const char *s2, size_t l2) { if (l2 == 0) return s1; /* empty strings are everywhere */ else if (l2 > l1) return NULL; /* avoids a negative `l1' */ else { const char *init; /* to search for a `*s2' inside `s1' */ l2--; /* 1st char will be checked by `memchr' */ l1 = l1-l2; /* `s2' cannot be found after that */ while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) { init++; /* 1st char is already checked */ if (memcmp(init, s2+1, l2) == 0) return init-1; else { /* correct `l1' and `s1' to try again */ l1 -= init-s1; s1 = init; } } return NULL; /* not found */ } } static void push_onecapture (MatchState *ms, int i, const char *s, const char *e) { if (i >= ms->level) { if (i == 0) /* ms->level == 0, too */ lua_pushlstring(ms->L, s, e - s); /* add whole match */ else luaL_error(ms->L, "invalid capture index"); } else { ptrdiff_t l = ms->capture[i].len; if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture"); if (l == CAP_POSITION) lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1); else lua_pushlstring(ms->L, ms->capture[i].init, l); } } static int push_captures (MatchState *ms, const char *s, const char *e) { int i; int nlevels = (ms->level == 0 && s) ? 1 : ms->level; luaL_checkstack(ms->L, nlevels, "too many captures"); for (i = 0; i < nlevels; i++) push_onecapture(ms, i, s, e); return nlevels; /* number of strings pushed */ } /* check whether pattern has no special characters */ static int nospecials (const char *p, size_t l) { size_t upto = 0; do { if (strpbrk(p + upto, SPECIALS)) return 0; /* pattern has a special character */ upto += strlen(p + upto) + 1; /* may have more after \0 */ } while (upto <= l); return 1; /* no special chars found */ } static int str_find_aux (lua_State *L, int find) { size_t ls, lp; const char *s = luaL_checklstring(L, 1, &ls); const char *p = luaL_checklstring(L, 2, &lp); size_t init = posrelat(luaL_optinteger(L, 3, 1), ls); if (init < 1) init = 1; else if (init > ls + 1) { /* start after string's end? */ lua_pushnil(L); /* cannot find anything */ return 1; } /* explicit request or no special characters? */ if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) { /* do a plain search */ const char *s2 = lmemfind(s + init - 1, ls - init + 1, p, lp); if (s2) { lua_pushinteger(L, s2 - s + 1); lua_pushinteger(L, s2 - s + lp); return 2; } } else { MatchState ms; const char *s1 = s + init - 1; int anchor = (*p == '^'); if (anchor) { p++; lp--; /* skip anchor character */ } ms.L = L; ms.matchdepth = MAXCCALLS; ms.src_init = s; ms.src_end = s + ls; ms.p_end = p + lp; do { const char *res; ms.level = 0; lua_assert(ms.matchdepth == MAXCCALLS); if ((res=match(&ms, s1, p)) != NULL) { if (find) { lua_pushinteger(L, s1 - s + 1); /* start */ lua_pushinteger(L, res - s); /* end */ return push_captures(&ms, NULL, 0) + 2; } else return push_captures(&ms, s1, res); } } while (s1++ < ms.src_end && !anchor); } lua_pushnil(L); /* not found */ return 1; } static int str_find (lua_State *L) { return str_find_aux(L, 1); } static int str_match (lua_State *L) { return str_find_aux(L, 0); } static int gmatch_aux (lua_State *L) { MatchState ms; size_t ls, lp; const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls); const char *p = lua_tolstring(L, lua_upvalueindex(2), &lp); const char *src; ms.L = L; ms.matchdepth = MAXCCALLS; ms.src_init = s; ms.src_end = s+ls; ms.p_end = p + lp; for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3)); src <= ms.src_end; src++) { const char *e; ms.level = 0; lua_assert(ms.matchdepth == MAXCCALLS); if ((e = match(&ms, src, p)) != NULL) { lua_Integer newstart = e-s; if (e == src) newstart++; /* empty match? go at least one position */ lua_pushinteger(L, newstart); lua_replace(L, lua_upvalueindex(3)); return push_captures(&ms, src, e); } } return 0; /* not found */ } static int str_gmatch (lua_State *L) { luaL_checkstring(L, 1); luaL_checkstring(L, 2); lua_settop(L, 2); lua_pushinteger(L, 0); lua_pushcclosure(L, gmatch_aux, 3); return 1; } static void add_s (MatchState *ms, luaL_Buffer *b, const char *s, const char *e) { size_t l, i; const char *news = lua_tolstring(ms->L, 3, &l); for (i = 0; i < l; i++) { if (news[i] != L_ESC) luaL_addchar(b, news[i]); else { i++; /* skip ESC */ if (!isdigit(uchar(news[i]))) { if (news[i] != L_ESC) luaL_error(ms->L, "invalid use of " LUA_QL("%c") " in replacement string", L_ESC); luaL_addchar(b, news[i]); } else if (news[i] == '0') luaL_addlstring(b, s, e - s); else { push_onecapture(ms, news[i] - '1', s, e); luaL_addvalue(b); /* add capture to accumulated result */ } } } } static void add_value (MatchState *ms, luaL_Buffer *b, const char *s, const char *e, int tr) { lua_State *L = ms->L; switch (tr) { case LUA_TFUNCTION: { int n; lua_pushvalue(L, 3); n = push_captures(ms, s, e); lua_call(L, n, 1); break; } case LUA_TTABLE: { push_onecapture(ms, 0, s, e); lua_gettable(L, 3); break; } default: { /* LUA_TNUMBER or LUA_TSTRING */ add_s(ms, b, s, e); return; } } if (!lua_toboolean(L, -1)) { /* nil or false? */ lua_pop(L, 1); lua_pushlstring(L, s, e - s); /* keep original text */ } else if (!lua_isstring(L, -1)) luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1)); luaL_addvalue(b); /* add result to accumulator */ } static int str_gsub (lua_State *L) { size_t srcl, lp; const char *src = luaL_checklstring(L, 1, &srcl); const char *p = luaL_checklstring(L, 2, &lp); int tr = lua_type(L, 3); size_t max_s = luaL_optinteger(L, 4, srcl+1); int anchor = (*p == '^'); size_t n = 0; MatchState ms; luaL_Buffer b; luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING || tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3, "string/function/table expected"); luaL_buffinit(L, &b); if (anchor) { p++; lp--; /* skip anchor character */ } ms.L = L; ms.matchdepth = MAXCCALLS; ms.src_init = src; ms.src_end = src+srcl; ms.p_end = p + lp; while (n < max_s) { const char *e; ms.level = 0; lua_assert(ms.matchdepth == MAXCCALLS); e = match(&ms, src, p); if (e) { n++; add_value(&ms, &b, src, e, tr); } if (e && e>src) /* non empty match? */ src = e; /* skip it */ else if (src < ms.src_end) luaL_addchar(&b, *src++); else break; if (anchor) break; } luaL_addlstring(&b, src, ms.src_end-src); luaL_pushresult(&b); lua_pushinteger(L, n); /* number of substitutions */ return 2; } /* }====================================================== */ /* ** {====================================================== ** STRING FORMAT ** ======================================================= */ /* ** LUA_INTFRMLEN is the length modifier for integer conversions in ** 'string.format'; LUA_INTFRM_T is the integer type corresponding to ** the previous length */ #if !defined(LUA_INTFRMLEN) /* { */ #if defined(LUA_USE_LONGLONG) #define LUA_INTFRMLEN "ll" #define LUA_INTFRM_T long long #else #define LUA_INTFRMLEN "l" #define LUA_INTFRM_T long #endif #endif /* } */ /* ** LUA_FLTFRMLEN is the length modifier for float conversions in ** 'string.format'; LUA_FLTFRM_T is the float type corresponding to ** the previous length */ #if !defined(LUA_FLTFRMLEN) #define LUA_FLTFRMLEN "" #define LUA_FLTFRM_T double #endif /* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */ #define MAX_ITEM 512 /* valid flags in a format specification */ #define FLAGS "-+ #0" /* ** maximum size of each format specification (such as '%-099.99d') ** (+10 accounts for %99.99x plus margin of error) */ #define MAX_FORMAT (sizeof(FLAGS) + sizeof(LUA_INTFRMLEN) + 10) static void addquoted (lua_State *L, luaL_Buffer *b, int arg) { size_t l; const char *s = luaL_checklstring(L, arg, &l); luaL_addchar(b, '"'); while (l--) { if (*s == '"' || *s == '\\' || *s == '\n') { luaL_addchar(b, '\\'); luaL_addchar(b, *s); } else if (*s == '\0' || iscntrl(uchar(*s))) { char buff[10]; if (!isdigit(uchar(*(s+1)))) sprintf(buff, "\\%d", (int)uchar(*s)); else sprintf(buff, "\\%03d", (int)uchar(*s)); luaL_addstring(b, buff); } else luaL_addchar(b, *s); s++; } luaL_addchar(b, '"'); } static const char *scanformat (lua_State *L, const char *strfrmt, char *form) { const char *p = strfrmt; while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++; /* skip flags */ if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char)) luaL_error(L, "invalid format (repeated flags)"); if (isdigit(uchar(*p))) p++; /* skip width */ if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ if (*p == '.') { p++; if (isdigit(uchar(*p))) p++; /* skip precision */ if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ } if (isdigit(uchar(*p))) luaL_error(L, "invalid format (width or precision too long)"); *(form++) = '%'; memcpy(form, strfrmt, (p - strfrmt + 1) * sizeof(char)); form += p - strfrmt + 1; *form = '\0'; return p; } /* ** add length modifier into formats */ static void addlenmod (char *form, const char *lenmod) { size_t l = strlen(form); size_t lm = strlen(lenmod); char spec = form[l - 1]; strcpy(form + l - 1, lenmod); form[l + lm - 1] = spec; form[l + lm] = '\0'; } static int str_format (lua_State *L) { int top = lua_gettop(L); int arg = 1; size_t sfl; const char *strfrmt = luaL_checklstring(L, arg, &sfl); const char *strfrmt_end = strfrmt+sfl; luaL_Buffer b; luaL_buffinit(L, &b); while (strfrmt < strfrmt_end) { if (*strfrmt != L_ESC) luaL_addchar(&b, *strfrmt++); else if (*++strfrmt == L_ESC) luaL_addchar(&b, *strfrmt++); /* %% */ else { /* format item */ char form[MAX_FORMAT]; /* to store the format (`%...') */ char *buff = luaL_prepbuffsize(&b, MAX_ITEM); /* to put formatted item */ int nb = 0; /* number of bytes in added item */ if (++arg > top) luaL_argerror(L, arg, "no value"); strfrmt = scanformat(L, strfrmt, form); switch (*strfrmt++) { case 'c': { nb = str_sprintf(buff, form, luaL_checkint(L, arg)); break; } case 'd': case 'i': { lua_Number n = luaL_checknumber(L, arg); LUA_INTFRM_T ni = (LUA_INTFRM_T)n; lua_Number diff = n - (lua_Number)ni; luaL_argcheck(L, -1 < diff && diff < 1, arg, "not a number in proper range"); addlenmod(form, LUA_INTFRMLEN); nb = str_sprintf(buff, form, ni); break; } case 'o': case 'u': case 'x': case 'X': { lua_Number n = luaL_checknumber(L, arg); unsigned LUA_INTFRM_T ni = (unsigned LUA_INTFRM_T)n; lua_Number diff = n - (lua_Number)ni; luaL_argcheck(L, -1 < diff && diff < 1, arg, "not a non-negative number in proper range"); addlenmod(form, LUA_INTFRMLEN); nb = str_sprintf(buff, form, ni); break; } #if defined(LUA_USE_FLOAT_FORMATS) case 'e': case 'E': case 'f': #if defined(LUA_USE_AFORMAT) case 'a': case 'A': #endif case 'g': case 'G': { addlenmod(form, LUA_FLTFRMLEN); nb = str_sprintf(buff, form, (LUA_FLTFRM_T)luaL_checknumber(L, arg)); break; } #endif case 'q': { addquoted(L, &b, arg); break; } case 's': { size_t l; const char *s = luaL_tolstring(L, arg, &l); if (!strchr(form, '.') && l >= 100) { /* no precision and string is too long to be formatted; keep original string */ luaL_addvalue(&b); break; } else { nb = str_sprintf(buff, form, s); lua_pop(L, 1); /* remove result from 'luaL_tolstring' */ break; } } default: { /* also treat cases `pnLlh' */ return luaL_error(L, "invalid option " LUA_QL("%%%c") " to " LUA_QL("format"), *(strfrmt - 1)); } } luaL_addsize(&b, nb); } } luaL_pushresult(&b); return 1; } /* }====================================================== */ static const luaL_Reg strlib[] = { {"byte", str_byte}, {"char", str_char}, {"dump", str_dump}, {"find", str_find}, {"format", str_format}, {"gmatch", str_gmatch}, {"gsub", str_gsub}, {"len", str_len}, {"lower", str_lower}, {"match", str_match}, {"rep", str_rep}, {"reverse", str_reverse}, {"sub", str_sub}, {"upper", str_upper}, {NULL, NULL} }; static void createmetatable (lua_State *L) { lua_createtable(L, 0, 1); /* table to be metatable for strings */ lua_pushliteral(L, ""); /* dummy string */ lua_pushvalue(L, -2); /* copy table */ lua_setmetatable(L, -2); /* set table as metatable for strings */ lua_pop(L, 1); /* pop dummy string */ lua_pushvalue(L, -2); /* get string library */ lua_setfield(L, -2, "__index"); /* metatable.__index = string */ lua_pop(L, 1); /* pop metatable */ } /* ** Open string library */ LUAMOD_API int luaopen_string (lua_State *L) { luaL_newlib(L, strlib); createmetatable(L); return 1; }