man 3 printf
#include <stdio.h>
int printf(const char *restrict format, ...);
int fprintf(FILE *restrict stream,
const char *restrict format, ...);
int dprintf(int fd,
const char *restrict format, ...);
int sprintf(char *restrict str,
const char *restrict format, ...);
int snprintf(char *restrict str, size_t size,
const char *restrict format, ...);
#include <stdarg.h>
int vprintf(const char *restrict format, va_list ap);
int vfprintf(FILE *restrict stream,
const char *restrict format, va_list ap);
int vdprintf(int fd,
const char *restrict format, va_list ap);
int vsprintf(char *restrict str,
const char *restrict format, va_list ap);
int vsnprintf(char *restrict str, size_t size,
const char *restrict format, va_list ap);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
snprintf(), vsnprintf():
_XOPEN_SOURCE >= 500 || _ISOC99_SOURCE
|| /* Glibc <= 2.19: */ _BSD_SOURCE
dprintf(), vdprintf():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE