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
