/*
** $Id: lstrlib.c,v 1.254 2016/12/22 13:08:50 roberto Exp $
** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h
*/
#define lstrlib_c
#define LUA_LIB
#include "lprefix.h"
#include <ctype.h>
#include <float.h>
#include <limits.h>
#include <locale.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#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, but must fit in
** an unsigned char.
*/
#if !defined(LUA_MAXCAPTURES)
#define LUA_MAXCAPTURES 32
#endif
/* macro to 'unsign' a character */
#define uchar(c) ((unsigned char)(c))
/*
** Some sizes are better limited to fit in 'int', but must also fit in
** 'size_t'. (We assume that 'lua_Integer' cannot be smaller than 'int'.)
*/
#define MAX_SIZET ((size_t)(~(size_t)0))
#define MAXSIZE \
(sizeof(size_t) < sizeof(int) ? MAX_SIZET : (size_t)(INT_MAX))
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 lua_Integer posrelat (lua_Integer pos, size_t len) {
if (pos >= 0) return pos;
else if (0u - (size_t)pos > len) return 0;
else return (lua_Integer)len + pos + 1;
}
static int str_sub (lua_State *L) {
size_t l;
const char *s = luaL_checklstring(L, 1, &l);
lua_Integer start = posrelat(luaL_checkinteger(L, 2), l);
lua_Integer end = posrelat(luaL_optinteger(L, 3, -1), l);
if (start < 1) start = 1;
if (end > (lua_Integer)l) end = l;
if (start <= end)
lua_pushlstring(L, s + start - 1, (size_t)(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<l; i++)
p[i] = tolower(uchar(s[i]));
luaL_pushresultsize(&b, l);
return 1;
}
static int str_upper (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<l; i++)
p[i] = toupper(uchar(s[i]));
luaL_pushresultsize(&b, l);
return 1;
}
static int str_rep (lua_State *L) {
size_t l, lsep;
const char *s = luaL_checklstring(L, 1, &l);
lua_Integer n = luaL_checkinteger(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 = (size_t)n * l + (size_t)(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) { /* empty 'memcpy' is not that cheap */
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);
lua_Integer posi = posrelat(luaL_optinteger(L, 2, 1), l);
lua_Integer pose = posrelat(luaL_optinteger(L, 3, posi), l);
int n, i;
if (posi < 1) posi = 1;
if (pose > (lua_Integer)l) pose = l;
if (posi > pose) return 0; /* empty interval; return no values */
if (pose - posi >= INT_MAX) /* arithmetic overflow? */
return luaL_error(L, "string slice too long");
n = (int)(pose - posi) + 1;
luaL_checkstack(L, n, "string slice too long");
for (i=0; i<n; i++)
lua_pushinteger(L, uchar(s[posi+i-1]));
return n;
}
static int str_char (lua_State *L) {
int n = lua_gettop(L); /* number of arguments */
int i;
luaL_Buffer b;
char *p = luaL_buffinitsize(L, &b, n);
for (i=1; i<=n; i++) {
lua_Integer c = luaL_checkinteger(L, i);
luaL_argcheck(L, uchar(c) == c, i, "value out of range");
p[i - 1] = uchar(c);
}
luaL_pushresultsize(&b, n);
return 1;
}
static int writer (lua_State *L, const void *b, size_t size, void *B) {
(void)L;
luaL_addlstring((luaL_Buffer *) B, (const char *)b, size);
return 0;
}
static int str_dump (lua_State *L) {
luaL_Buffer b;
int strip = lua_toboolean(L, 2);
luaL_checktype(L, 1, LUA_TFUNCTION);
lua_settop(L, 1);
luaL_buffinit(L,&b);
if (lua_dump(L, writer, &b, strip) != 0)
return luaL_error(L, "unable to dump given function");
luaL_pushresult(&b);
return 1;
}
/*
** {======================================================
** PATTERN MATCHING
** =======================================================
*/
#define CAP_UNFINISHED (-1)
#define CAP_POSITION (-2)
typedef struct MatchState {
const char *src_init; /* init of source string */
const char *src_end; /* end ('\0') of source string */
const char *p_end; /* end ('\0') of pattern */
lua_State *L;
int matchdepth; /* control for recursive depth (to avoid C stack overflow) */
unsigned char level; /* total number of captures (finished or unfinished) */
struct {
const char *init;
ptrdiff_t len;
} capture[LUA_MAXCAPTURES];
} MatchState;
/* recursive function */
static const char *match (MatchState *ms, const char *s, const char *p);
/* maximum recursion depth for 'match' */
#if !defined(MAXCCALLS)
#define MAXCCALLS 200
#endif
#define L_ESC '%'
#define SPECIALS "^$*+?.([%-"
static int check_capture (MatchState *ms, int l) {
l -= '1';
if (l < 0 || l >= 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 '%%')");
return p+1;
}
case '[': {
if (*p == '^') p++;
do { /* look for a ']' */
if (p == ms->p_end)
luaL_error(ms->L, "malformed pattern (missing ']')");
if (*(p++) == L_ESC && p < ms->p_end)
p++; /* skip escapes (e.g. '%]') */
} while (*p != ']');
return p+1;
}
default: {
return p;
}
}
}
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