path: root/tests/lua/src/lstrlib.c

/*
** $Id: lstrlib.c,v 1.178 2012/08/14 18:12:34 roberto Exp $
** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h
*/


#include <ctype.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#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))



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<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;
}


/* reasonable limit to avoid arithmetic overflow */
#define MAXSIZE		((~(size_t)0) >> 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