DPRINTF(3) Linux Programmer’s Manual DPRINTF(3)
dprintf, vdprintf - print to a file descriptor
#define _GNU_SOURCE
#include <stdio.h>
int dprintf(int fd, const char *format, ...);
int vdprintf(int fd, const char *format, va_list ap);
The functions dprintf() and vdprintf() (as found in the glibc2 library)
are exact analogues of fprintf() and vfprintf(), except that they out‐
put to a file descriptor fd instead of to a given stream.
These functions are GNU extensions, not in C or POSIX. Clearly, the
names were badly chosen. Many systems (like MacOS) have incompatible
functions called dprintf(), usually some debugging version of printf(),
perhaps with a prototype like
void dprintf (int level, const char *format, ...);
where the first parameter is a debugging level (and output is to
stderr). Moreover, dprintf() (or DPRINTF) is also a popular macro name
for a debugging printf. So, probably, it is better to avoid this func‐
tion in programs intended to be portable.
A better name would have been fdprintf().
These functions are GNU extensions.
printf(3)
GNU 2001-12-18 DPRINTF(3)