# <inttypes.h>

**[<inttypes.h>](https://en.cppreference.com/w/c/header/inttypes)** solves a portability trap: `uint64_t` may be `unsigned long` on one platform and `unsigned long long` on another. The format macros (`PRIu64`, `PRIx64`) expand to the correct `printf`/`scanf` specifier for each platform.

Use `PRIu64`, `PRId64`, etc. instead of guessing `%llu` or `%lu`.

## Example

This example prints fixed-width integers portably using the PRI macros.

```c
// compile: gcc -o inttypesexample inttypesexample.c
// run: ./inttypesexample
// description: portable printf of fixed-width integers

#include <inttypes.h>
#include <stdio.h>

int main() {
    uint8_t a = 255;
    uint32_t b = 0xDEADBEEF;
    uint64_t c = UINT64_MAX;
    int64_t d = INT64_MIN;
    
    printf("uint8:  %" PRIu8 "\n", a);
    printf("uint32: %" PRIu32 " (0x%" PRIx32 ")\n", b, b);
    printf("uint64: %" PRIu64 "\n", c);
    printf("int64:  %" PRId64 "\n", d);
    
    return 0;
}
```