mirror of https://github.com/lua/lua
540 lines
13 KiB
C
540 lines
13 KiB
C
/*
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** $Id: lstrlib.c,v 1.13 1998/05/18 22:21:55 roberto Exp roberto $
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** Standard library for strings and pattern-matching
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** See Copyright Notice in lua.h
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*/
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#include <ctype.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "lauxlib.h"
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#include "lua.h"
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#include "lualib.h"
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static void addnchar (char *s, int n)
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{
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char *b = luaL_openspace(n);
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memcpy(b, s, n);
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luaL_addsize(n);
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}
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static void str_len (void)
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{
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long l;
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luaL_check_lstr(1, &l);
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lua_pushnumber(l);
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}
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static void closeandpush (void)
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{
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lua_pushlstring(luaL_buffer(), luaL_getsize());
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}
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static long posrelat (long pos, long len)
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{
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/* relative string position: negative means back from end */
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return (pos>=0) ? pos : len+pos+1;
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}
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static void str_sub (void)
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{
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long l;
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char *s = luaL_check_lstr(1, &l);
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long start = posrelat(luaL_check_number(2), l);
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long end = posrelat(luaL_opt_number(3, -1), l);
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if (1 <= start && start <= end && end <= l)
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lua_pushlstring(s+start-1, end-start+1);
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else lua_pushstring("");
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}
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static void str_lower (void)
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{
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long l;
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int i;
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char *s = luaL_check_lstr(1, &l);
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luaL_resetbuffer();
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for (i=0; i<l; i++)
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luaL_addchar(tolower((unsigned char)(s[i])));
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closeandpush();
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}
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static void str_upper (void)
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{
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long l;
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int i;
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char *s = luaL_check_lstr(1, &l);
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luaL_resetbuffer();
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for (i=0; i<l; i++)
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luaL_addchar(toupper((unsigned char)(s[i])));
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closeandpush();
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}
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static void str_rep (void)
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{
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long l;
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char *s = luaL_check_lstr(1, &l);
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int n = (int)luaL_check_number(2);
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luaL_resetbuffer();
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while (n-- > 0)
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addnchar(s, l);
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closeandpush();
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}
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static void str_byte (void)
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{
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long l;
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char *s = luaL_check_lstr(1, &l);
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long pos = posrelat(luaL_opt_number(2, 1), l);
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luaL_arg_check(0<pos && pos<=l, 2, "out of range");
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lua_pushnumber((unsigned char)s[pos-1]);
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}
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static void str_char (void) {
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int i = 0;
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luaL_resetbuffer();
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while (lua_getparam(++i) != LUA_NOOBJECT) {
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double c = luaL_check_number(i);
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luaL_arg_check((unsigned char)c == c, i, "invalid value");
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luaL_addchar((int)c);
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}
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closeandpush();
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}
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/*
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** =======================================================
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** PATTERN MATCHING
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** =======================================================
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*/
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#define MAX_CAPT 9
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struct Capture {
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int level; /* total number of captures (finished or unfinished) */
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char *src_end; /* end ('\0') of source string */
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struct {
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char *init;
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int len; /* -1 signals unfinished capture */
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} capture[MAX_CAPT];
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};
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#define ESC '%'
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#define SPECIALS "^$*?.([%-"
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static void push_captures (struct Capture *cap)
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{
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int i;
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for (i=0; i<cap->level; i++)
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lua_pushlstring(cap->capture[i].init, cap->capture[i].len);
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}
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static int check_cap (int l, struct Capture *cap)
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{
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l -= '1';
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if (!(0 <= l && l < cap->level && cap->capture[l].len != -1))
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lua_error("invalid capture index");
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return l;
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}
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static int capture_to_close (struct Capture *cap)
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{
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int level = cap->level;
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for (level--; level>=0; level--)
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if (cap->capture[level].len == -1) return level;
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lua_error("invalid pattern capture");
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return 0; /* to avoid warnings */
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}
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static char *bracket_end (char *p)
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{
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return (*p == 0) ? NULL : strchr((*p=='^') ? p+2 : p+1, ']');
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}
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static int matchclass (int c, int cl)
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{
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int res;
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switch (tolower(cl)) {
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case 'a' : res = isalpha(c); break;
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case 'c' : res = iscntrl(c); break;
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case 'd' : res = isdigit(c); break;
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case 'l' : res = islower(c); break;
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case 'p' : res = ispunct(c); break;
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case 's' : res = isspace(c); break;
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case 'u' : res = isupper(c); break;
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case 'w' : res = isalnum(c); break;
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case 'z' : res = (c == '\0'); break;
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default: return (cl == c);
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}
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return (islower((unsigned char)cl) ? res : !res);
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}
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int luaI_singlematch (int c, char *p, char **ep)
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{
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switch (*p) {
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case '.': /* matches any char */
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*ep = p+1;
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return 1;
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case '\0': /* end of pattern; matches nothing */
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*ep = p;
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return 0;
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case ESC:
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if (*(++p) == '\0')
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luaL_verror("incorrect pattern (ends with `%c')", ESC);
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*ep = p+1;
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return matchclass(c, (unsigned char)*p);
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case '[': {
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char *end = bracket_end(p+1);
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int sig = *(p+1) == '^' ? (p++, 0) : 1;
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if (end == NULL) lua_error("incorrect pattern (missing `]')");
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*ep = end+1;
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while (++p < end) {
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if (*p == ESC) {
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if (((p+1) < end) && matchclass(c, (unsigned char)*++p))
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return sig;
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}
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else if ((*(p+1) == '-') && (p+2 < end)) {
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p+=2;
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if ((unsigned char)*(p-2) <= c && c <= (unsigned char)*p)
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return sig;
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}
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else if ((unsigned char)*p == c) return sig;
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}
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return !sig;
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}
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default:
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*ep = p+1;
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return ((unsigned char)*p == c);
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}
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}
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static char *matchbalance (char *s, int b, int e, struct Capture *cap)
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{
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if (*s != b) return NULL;
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else {
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int cont = 1;
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while (++s < cap->src_end) {
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if (*s == e) {
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if (--cont == 0) return s+1;
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}
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else if (*s == b) cont++;
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}
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}
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return NULL; /* string ends out of balance */
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}
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static char *matchitem (char *s, char *p, struct Capture *cap, char **ep)
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{
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if (*p == ESC) {
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p++;
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if (isdigit((unsigned char)*p)) { /* capture */
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int l = check_cap(*p, cap);
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int len = cap->capture[l].len;
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*ep = p+1;
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if (cap->src_end-s >= len && memcmp(cap->capture[l].init, s, len) == 0)
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return s+len;
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else return NULL;
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}
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else if (*p == 'b') { /* balanced string */
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p++;
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if (*p == 0 || *(p+1) == 0)
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lua_error("unbalanced pattern");
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*ep = p+2;
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return matchbalance(s, *p, *(p+1), cap);
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}
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else p--; /* and go through */
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}
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/* "luaI_singlematch" sets "ep" (so must be called even when *s == 0) */
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return (luaI_singlematch((unsigned char)*s, p, ep) && s<cap->src_end) ?
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s+1 : NULL;
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}
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static char *match (char *s, char *p, struct Capture *cap)
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{
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init: /* using goto's to optimize tail recursion */
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switch (*p) {
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case '(': { /* start capture */
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char *res;
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if (cap->level >= MAX_CAPT) lua_error("too many captures");
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cap->capture[cap->level].init = s;
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cap->capture[cap->level].len = -1;
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cap->level++;
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if ((res=match(s, p+1, cap)) == NULL) /* match failed? */
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cap->level--; /* undo capture */
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return res;
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}
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case ')': { /* end capture */
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int l = capture_to_close(cap);
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char *res;
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cap->capture[l].len = s - cap->capture[l].init; /* close capture */
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if ((res = match(s, p+1, cap)) == NULL) /* match failed? */
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cap->capture[l].len = -1; /* undo capture */
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return res;
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}
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case '\0': case '$': /* (possibly) end of pattern */
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if (*p == 0 || (*(p+1) == 0 && s == cap->src_end))
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return s;
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/* else go through */
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default: { /* it is a pattern item */
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char *ep; /* get what is next */
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char *s1 = matchitem(s, p, cap, &ep);
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switch (*ep) {
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case '*': { /* repetition */
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char *res;
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if (s1 && s1>s && (res = match(s1, p, cap)))
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return res;
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p=ep+1; goto init; /* else return match(s, ep+1, cap); */
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}
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case '?': { /* optional */
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char *res;
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if (s1 && (res = match(s1, ep+1, cap)))
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return res;
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p=ep+1; goto init; /* else return match(s, ep+1, cap); */
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}
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case '-': { /* repetition */
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char *res;
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if ((res = match(s, ep+1, cap)) != 0)
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return res;
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else if (s1 && s1>s) {
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s = s1;
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goto init; /* return match(s1, p, cap); */
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}
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else
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return NULL;
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}
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default:
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if (s1) { s=s1; p=ep; goto init; } /* return match(s1, ep, cap); */
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else return NULL;
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}
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}
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}
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}
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static void str_find (void)
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{
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long l;
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char *s = luaL_check_lstr(1, &l);
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char *p = luaL_check_string(2);
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long init = posrelat(luaL_opt_number(3, 1), l) - 1;
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struct Capture cap;
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luaL_arg_check(0 <= init && init <= l, 3, "out of range");
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if (lua_getparam(4) != LUA_NOOBJECT ||
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strpbrk(p, SPECIALS) == NULL) { /* no special caracters? */
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char *s2 = strstr(s+init, p);
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if (s2) {
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lua_pushnumber(s2-s+1);
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lua_pushnumber(s2-s+strlen(p));
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}
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}
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else {
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int anchor = (*p == '^') ? (p++, 1) : 0;
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char *s1=s+init;
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cap.src_end = s+l;
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do {
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char *res;
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cap.level = 0;
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if ((res=match(s1, p, &cap)) != NULL) {
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lua_pushnumber(s1-s+1); /* start */
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lua_pushnumber(res-s); /* end */
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push_captures(&cap);
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return;
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}
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} while (s1++<cap.src_end && !anchor);
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}
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}
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static void add_s (lua_Object newp, struct Capture *cap)
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{
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if (lua_isstring(newp)) {
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char *news = lua_getstring(newp);
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int l = lua_strlen(newp);
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int i;
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for (i=0; i<l; i++) {
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if (news[i] != ESC)
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luaL_addchar(news[i]);
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else {
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i++; /* skip ESC */
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if (!isdigit((unsigned char)news[i]))
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luaL_addchar(news[i]);
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else {
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int level = check_cap(news[i], cap);
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addnchar(cap->capture[level].init, cap->capture[level].len);
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}
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}
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}
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}
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else { /* is a function */
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lua_Object res;
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int status;
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int oldbuff;
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lua_beginblock();
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push_captures(cap);
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/* function may use buffer, so save it and create a new one */
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oldbuff = luaL_newbuffer(0);
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status = lua_callfunction(newp);
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/* restore old buffer */
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luaL_oldbuffer(oldbuff);
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if (status != 0) {
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lua_endblock();
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lua_error(NULL);
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}
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res = lua_getresult(1);
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if (lua_isstring(res))
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addnchar(lua_getstring(res), lua_strlen(res));
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lua_endblock();
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}
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}
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static void str_gsub (void)
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{
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long srcl;
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char *src = luaL_check_lstr(1, &srcl);
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char *p = luaL_check_string(2);
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lua_Object newp = lua_getparam(3);
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int max_s = (int)luaL_opt_number(4, srcl+1);
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int anchor = (*p == '^') ? (p++, 1) : 0;
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int n = 0;
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struct Capture cap;
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luaL_arg_check(lua_isstring(newp) || lua_isfunction(newp), 3,
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"string or function expected");
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luaL_resetbuffer();
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cap.src_end = src+srcl;
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while (n < max_s) {
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char *e;
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cap.level = 0;
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e = match(src, p, &cap);
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if (e) {
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n++;
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add_s(newp, &cap);
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}
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if (e && e>src) /* non empty match? */
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src = e; /* skip it */
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else if (src < cap.src_end)
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luaL_addchar(*src++);
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else break;
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if (anchor) break;
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}
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addnchar(src, cap.src_end-src);
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closeandpush();
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lua_pushnumber(n); /* number of substitutions */
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}
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static void luaI_addquoted (char *s)
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{
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luaL_addchar('"');
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for (; *s; s++) {
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if (strchr("\"\\\n", *s))
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luaL_addchar('\\');
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luaL_addchar(*s);
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}
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luaL_addchar('"');
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}
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#define MAX_FORMAT 200
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static void str_format (void)
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{
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int arg = 1;
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char *strfrmt = luaL_check_string(arg);
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struct Capture cap;
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cap.src_end = strfrmt+strlen(strfrmt)+1;
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luaL_resetbuffer();
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while (*strfrmt) {
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if (*strfrmt != '%')
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luaL_addchar(*strfrmt++);
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else if (*++strfrmt == '%')
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luaL_addchar(*strfrmt++); /* %% */
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else { /* format item */
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char form[MAX_FORMAT]; /* store the format ('%...') */
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char *buff;
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char *initf = strfrmt;
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form[0] = '%';
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cap.level = 0;
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if (isdigit((unsigned char)initf[0]) && initf[1] == '$') {
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arg = initf[0] - '0';
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initf += 2; /* skip the 'n$' */
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}
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arg++;
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strfrmt = match(initf, "[-+ #0]*(%d*)%.?(%d*)", &cap);
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if (cap.capture[0].len > 2 || cap.capture[1].len > 2) /* < 100? */
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lua_error("invalid format (width or precision too long)");
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strncpy(form+1, initf, strfrmt-initf+1); /* +1 to include convertion */
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form[strfrmt-initf+2] = 0;
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buff = luaL_openspace(1000); /* to store the formatted value */
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switch (*strfrmt++) {
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case 'q':
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luaI_addquoted(luaL_check_string(arg));
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continue;
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case 's': {
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char *s = luaL_check_string(arg);
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buff = luaL_openspace(strlen(s));
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sprintf(buff, form, s);
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break;
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}
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case 'c': case 'd': case 'i':
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sprintf(buff, form, (int)luaL_check_number(arg));
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break;
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case 'o': case 'u': case 'x': case 'X':
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sprintf(buff, form, (unsigned int)luaL_check_number(arg));
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break;
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case 'e': case 'E': case 'f': case 'g': case 'G':
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sprintf(buff, form, luaL_check_number(arg));
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break;
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default: /* also treat cases 'pnLlh' */
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lua_error("invalid option in `format'");
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}
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luaL_addsize(strlen(buff));
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}
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}
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closeandpush(); /* push the result */
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}
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static struct luaL_reg strlib[] = {
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{"strlen", str_len},
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{"strsub", str_sub},
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{"strlower", str_lower},
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{"strupper", str_upper},
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{"strchar", str_char},
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{"strrep", str_rep},
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{"ascii", str_byte}, /* for compatibility */
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{"strbyte", str_byte},
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{"format", str_format},
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{"strfind", str_find},
|
|
{"gsub", str_gsub}
|
|
};
|
|
|
|
|
|
/*
|
|
** Open string library
|
|
*/
|
|
void strlib_open (void)
|
|
{
|
|
luaL_openlib(strlib, (sizeof(strlib)/sizeof(strlib[0])));
|
|
}
|