Windows Development

LoadString(hModule, valid_string_id, buf, buflen)       returns length of string
LoadString(hModule, invalid_string_id, buf, buflen)     returns 0
LoadString(hModule, valid_string_id, buf, 0)            returns -1
LoadString(hModule, valid_string_id, NULL, buflen)      throws an exception
LoadString(hModule, valid_string_id, NULL, 0)           throws an exception

#include <windows.h>
#include <stdio.h>
#include "test.h"   // resource include file

#define ARRAYLENGTH(a) (sizeof(a)/sizeof((a)[0]))

int main (int argc, char **argv)
{
    char buf[300];
    int len;
    HMODULE hModule = GetModuleHandle(NULL);

#define TEST_FUNC_CALL(expression) \
    buf[0] = '?';                  \
    buf[1] = 0;                    \
    printf("%s\n", #expression);   \
    __try {                        \
        len = expression;          \
        printf("... returned %d; buf: %s\n\n", len, buf); \
    }                              \
    __except(EXCEPTION_EXECUTE_HANDLER) {   \
        printf("... threw an exception\n\n"); \
    }
   
    TEST_FUNC_CALL(  LoadString(hModule, IDS_STRING1, buf,  ARRAYLENGTH(buf))  ) // valid string ID
    TEST_FUNC_CALL(  LoadString(hModule, 9999,        buf,  ARRAYLENGTH(buf))  ) // invalid ID
    TEST_FUNC_CALL(  LoadString(hModule, IDS_STRING1, buf,  0)                 ) // zero size
    TEST_FUNC_CALL(  LoadString(hModule, IDS_STRING1, NULL, ARRAYLENGTH(buf))  ) // null buffer
    TEST_FUNC_CALL(  LoadString(hModule, IDS_STRING1, NULL, 0)                 ) // both

    return 0;
}