mirror of
https://github.com/lua/lua.git
synced 2024-11-24 10:43:44 +08:00
535 lines
12 KiB
C
535 lines
12 KiB
C
/*
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** $Id: lstrlib.c,v 1.1 1997/08/14 19:47:57 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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struct lbuff {
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char *b;
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size_t max;
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size_t size;
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};
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static struct lbuff lbuffer = {NULL, 0, 0};
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static char *strbuffer (unsigned long size)
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{
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if (size > lbuffer.max) {
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/* ANSI "realloc" doesn't need this test, but some machines (Sun!)
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don't follow ANSI */
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lbuffer.b = (lbuffer.b) ? realloc(lbuffer.b, lbuffer.max=size) :
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malloc(lbuffer.max=size);
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if (lbuffer.b == NULL)
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lua_error("memory overflow");
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}
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return lbuffer.b;
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}
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static char *openspace (unsigned long size)
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{
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char *buff = strbuffer(lbuffer.size+size);
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return buff+lbuffer.size;
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}
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char *luaI_addchar (int c)
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{
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if (lbuffer.size >= lbuffer.max)
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strbuffer(lbuffer.max == 0 ? 100 : lbuffer.max*2);
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lbuffer.b[lbuffer.size++] = c;
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return lbuffer.b;
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}
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void luaI_emptybuff (void)
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{
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lbuffer.size = 0; /* prepare for next string */
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}
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static void addnchar (char *s, int n)
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{
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char *b = openspace(n);
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strncpy(b, s, n);
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lbuffer.size += n;
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}
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static void addstr (char *s)
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{
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addnchar(s, strlen(s));
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}
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static void str_len (void)
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{
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lua_pushnumber(strlen(luaL_check_string(1)));
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}
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static void str_sub (void)
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{
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char *s = luaL_check_string(1);
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long l = strlen(s);
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long start = (long)luaL_check_number(2);
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long end = (long)luaL_opt_number(3, -1);
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if (start < 0) start = l+start+1;
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if (end < 0) end = l+end+1;
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if (1 <= start && start <= end && end <= l) {
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luaI_emptybuff();
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addnchar(s+start-1, end-start+1);
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lua_pushstring(luaI_addchar(0));
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}
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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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char *s;
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luaI_emptybuff();
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for (s = luaL_check_string(1); *s; s++)
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luaI_addchar(tolower((unsigned char)*s));
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lua_pushstring(luaI_addchar(0));
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}
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static void str_upper (void)
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{
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char *s;
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luaI_emptybuff();
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for (s = luaL_check_string(1); *s; s++)
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luaI_addchar(toupper((unsigned char)*s));
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lua_pushstring(luaI_addchar(0));
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}
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static void str_rep (void)
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{
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char *s = luaL_check_string(1);
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int n = (int)luaL_check_number(2);
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luaI_emptybuff();
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while (n-- > 0)
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addstr(s);
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lua_pushstring(luaI_addchar(0));
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}
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static void str_ascii (void)
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{
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char *s = luaL_check_string(1);
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long pos = (long)luaL_opt_number(2, 1) - 1;
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luaL_arg_check(0<=pos && pos<strlen(s), 2, "out of range");
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lua_pushnumber((unsigned char)s[pos]);
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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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static 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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static int num_captures; /* only valid after a sucessful call to match */
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#define ESC '%'
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#define SPECIALS "^$*?.([%-"
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static void push_captures (void)
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{
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int i;
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for (i=0; i<num_captures; i++) {
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int l = capture[i].len;
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char *buff = openspace(l+1);
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if (l == -1) lua_error("unfinished capture");
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strncpy(buff, capture[i].init, l);
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buff[l] = 0;
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lua_pushstring(buff);
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}
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}
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static int check_cap (int l, int level)
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{
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l -= '1';
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if (!(0 <= l && l < level && 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 (int level)
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{
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for (level--; level>=0; level--)
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if (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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if (c == 0) return 0;
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switch (tolower((unsigned char)cl)) {
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case 'a' : res = isalpha((unsigned char)c); break;
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case 'c' : res = iscntrl((unsigned char)c); break;
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case 'd' : res = isdigit((unsigned char)c); break;
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case 'l' : res = islower((unsigned char)c); break;
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case 'p' : res = ispunct((unsigned char)c); break;
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case 's' : res = isspace((unsigned char)c); break;
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case 'u' : res = isupper((unsigned char)c); break;
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case 'w' : res = isalnum((unsigned char)c); 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 '\0':
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*ep = p;
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return 0;
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case '.':
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*ep = p+1;
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return (c != 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, *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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if (c == 0) return 0;
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while (++p < end) {
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if (*p == ESC) {
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if (((p+1) < end) && matchclass(c, *++p)) 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 (*(p-2) <= c && c <= *p) return sig;
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}
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else if (*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 (*p == c);
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}
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}
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static char *matchbalance (char *s, int b, int e)
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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)) {
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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, int level, 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, level);
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*ep = p+1;
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if (strncmp(capture[l].init, s, capture[l].len) == 0)
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return s+capture[l].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("bad balanced pattern specification");
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*ep = p+2;
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return matchbalance(s, *p, *(p+1));
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}
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else p--; /* and go through */
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}
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return (luaI_singlematch(*s, p, ep) ? s+1 : NULL);
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}
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static char *match (char *s, char *p, int level)
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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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if (level >= MAX_CAPT) lua_error("too many captures");
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capture[level].init = s;
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capture[level].len = -1;
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level++; p++; goto init; /* return match(s, p+1, level); */
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case ')': { /* end capture */
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int l = capture_to_close(level);
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char *res;
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capture[l].len = s - capture[l].init; /* close capture */
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if ((res = match(s, p+1, level)) == NULL) /* match failed? */
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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 == 0)) {
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num_captures = level;
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return s;
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}
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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, level, &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 && (res = match(s1, p, level)))
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return res;
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p=ep+1; goto init; /* else return match(s, ep+1, level); */
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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, level)) != 0)
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return res;
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else if (s1) {
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s = s1;
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goto init; /* return match(s1, p, level); */
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}
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else
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return NULL;
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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, level)))
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return res;
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p=ep+1; goto init; /* else return match(s, ep+1, level); */
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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, level); */
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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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char *s = luaL_check_string(1);
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char *p = luaL_check_string(2);
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long init = (long)luaL_opt_number(3, 1) - 1;
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luaL_arg_check(0 <= init && init <= strlen(s), 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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do {
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char *res;
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if ((res=match(s1, p, 0)) != 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();
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return;
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}
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} while (*s1++ && !anchor);
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}
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}
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static void add_s (lua_Object newp)
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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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while (*news) {
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if (*news != ESC || !isdigit((unsigned char)*++news))
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luaI_addchar(*news++);
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else {
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int l = check_cap(*news++, num_captures);
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addnchar(capture[l].init, capture[l].len);
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}
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}
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}
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else if (lua_isfunction(newp)) {
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lua_Object res;
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struct lbuff oldbuff;
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int status;
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lua_beginblock();
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push_captures();
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/* function may use lbuffer, so save it and create a luaM_new one */
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oldbuff = lbuffer;
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lbuffer.b = NULL; lbuffer.max = lbuffer.size = 0;
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status = lua_callfunction(newp);
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/* restore old buffer */
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free(lbuffer.b);
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lbuffer = oldbuff;
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if (status != 0)
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lua_error(NULL);
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res = lua_getresult(1);
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addstr(lua_isstring(res) ? lua_getstring(res) : "");
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lua_endblock();
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}
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else luaL_arg_check(0, 3, NULL);
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}
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static void str_gsub (void)
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{
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char *src = luaL_check_string(1);
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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, strlen(src)+1);
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int anchor = (*p == '^') ? (p++, 1) : 0;
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int n = 0;
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luaI_emptybuff();
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while (n < max_s) {
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char *e = match(src, p, 0);
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if (e) {
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n++;
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add_s(newp);
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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)
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luaI_addchar(*src++);
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else break;
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if (anchor) break;
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}
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addstr(src);
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lua_pushstring(luaI_addchar(0));
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lua_pushnumber(n); /* number of substitutions */
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}
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void luaI_addquoted (char *s)
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{
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luaI_addchar('"');
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for (; *s; s++) {
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if (strchr("\"\\\n", *s))
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luaI_addchar('\\');
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luaI_addchar(*s);
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}
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luaI_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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luaI_emptybuff(); /* initialize */
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while (*strfrmt) {
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if (*strfrmt != '%')
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luaI_addchar(*strfrmt++);
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else if (*++strfrmt == '%')
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luaI_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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strfrmt = match(strfrmt, "%d?%$?[-+ #]*(%d*)%.?(%d*)", 0);
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if (capture[0].len > 3 || capture[1].len > 3) /* < 1000? */
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lua_error("invalid format (width or precision too long)");
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if (isdigit((unsigned char)initf[0]) && initf[1] == '$') {
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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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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 = openspace(1000); /* to store the formated 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 = 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': case 'o':
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case 'u': case 'x': case 'X':
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sprintf(buff, form, (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 format option in function `format'");
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}
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lbuffer.size += strlen(buff);
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}
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}
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lua_pushstring(luaI_addchar(0)); /* 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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{"strrep", str_rep},
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{"ascii", str_ascii},
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{"format", str_format},
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{"strfind", str_find},
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{"gsub", str_gsub}
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};
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/*
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** Open string library
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*/
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void strlib_open (void)
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{
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luaL_openlib(strlib, (sizeof(strlib)/sizeof(strlib[0])));
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}
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