Printf long long int in C with GCC?

Question

How do I printf long long int and also unsigned long long int in C99 using GCC?

I have searched the other posts which suggest to use %lld but it gives these warnings:

warning#1: unknown conversion type character 'l' in format [-Wformat]|
warning#2: too many arguments for format [-Wformat-extra-args]|

For the following attempt:

#include <stdio.h>

int main()
{
   long long int x = 0;
   unsigned long long int y = 0;
   printf("%lld\n", x);
   printf("%llu\n", y);
}

Answer 1

If you are on windows and using mingw, gcc uses the win32 runtime, where printf needs %I64d for a 64 bit integer. (and %I64u for an unsinged 64 bit integer)

For most other platforms you'd use %lld for printing a long long. (and %llu if it's unsigned). This is standarized in C99.

gcc doesn't come with a full C runtime, it defers to the platform it's running on - so the general case is that you need to consult the documentation for your particular platform - independent of gcc.

Answer 2

For portable code, the macros in inttypes.h may be used. They expand to the correct ones for the platform.

Eg for 64 bit integer, the macro PRId64 can be used.

int64_t n = 7;
printf("n is %" PRId64 "\n", n);

Answer 3

尝试更新您的编译器，我在 Windows 7 Starter x86 上使用 GCC 4.7 和 MinGW，它在 C99 和 C11 中使用相同的选项编译得很好。

Answer 4

You can try settings of code::block , there is a complier..., then you select in C mode.