vsprintf (3) Linux Manual Page

printf, fprintf, dprintf, sprintf, snprintf, vprintf, vfprintf, vdprintf, vsprintf, vsnprintf – formatted output conversion

Synopsis

#include <stdio.h>

int printf(const char *format, ...);
int fprintf(FILE *stream, const char *format, ...);
int dprintf(int fd, const char *format, ...);
int sprintf(char *str, const char *format, ...);
int snprintf(char *str, size_t size, const char *format, ...);

#include <stdarg.h>

int vprintf(const char *format, va_list ap);
int vfprintf(FILE *stream, const char *format, va_list ap);
int vdprintf(int fd, const char *format, va_list ap);
int vsprintf(char *str, const char *format, va_list ap);
int vsnprintf(char *str, size_t size, const char *format, va_list ap);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)): snprintf(), vsnprintf():

_XOPEN_SOURCE >= 500 || _ISOC99_SOURCE ||
    || /* Glibc versions <= 2.19: */ _BSD_SOURCE

dprintf(), vdprintf():

Since glibc 2.10:

_POSIX_C_SOURCE >= 200809L

Before glibc 2.10:

_GNU_SOURCE

Description

The functions in the printf() family produce output according to a format as described below. The functions printf() and vprintf() write output to stdout, the standard output stream; fprintf() and vfprintf() write output to the given output stream; sprintf(), snprintf(), vsprintf(), and vsnprintf() write to the character string str. The function dprintf() is the same as fprintf() except that it outputs to a file descriptor, fd, instead of to a stdio stream. The functions snprintf() and vsnprintf() write at most size bytes (including the terminating null byte (‘