gcc complains about tmpnam when using the -Werror option, I propose this code to rectify that:
typedef unsigned int lua_uint;
size_t u2a( char *str, size_t size, lua_uint val, lua_uint base, lua_uint small ) {
static const char bstr[] = "0123456789ABCDEF";
static const char sstr[] = "0123456789abcdef";
static const size_t min = (sizeof(int) * CHAR_BIT);
const char *s = small ? sstr : bstr;
size_t i = 0;
if ( !str || !size || base < 2 || base > strlen(s) ) return 0;
--size;
if ( size < min ) {
memset( str, 0, size );
return 0;
}
while ( val > 0u ) {
str[i++] = s[val % base];
val /= base;
}
str[i] = 0;
return i;
}
/* Avoids unistd.h, can expect sys/stat.h on all supported systems */
#include <sys/stat.h>
size_t tmpname( char *str, size_t size ) {
size_t i;
struct stat m = {0};
if ( u2a( str, --size, 0, 2, 0 ) == 0 ) return 0;
str[0] = '_';
++str;
do {
i = u2a( str, size, rand(), 16, 1 );
} while ( stat(str,&m) == 1 );
return i;
}
static int os_tmpname (lua_State *L) {
char buff[LUA_TMPNAMBUFSIZE];
if ( tmpname(buff, LUA_TMPNAMBUFSIZE) == 0 )
return luaL_error(L, "unable to generate a unique filename");
lua_pushstring(L, buff);
return 1;
}
