redhat man page for dprintf

DPRINTF(3)						     Linux Programmer's Manual							DPRINTF(3)

NAME
       dprintf, vdprintf - print to a file descriptor

SYNOPSIS
       #define _GNU_SOURCE
       #include <stdio.h>

       int dprintf(int fd, const char *format, ...);

       int vdprintf(int fd, const char *format, va_list ap);

DESCRIPTION
       The functions dprintf and vdprintf (as found in the glibc2 library) are exact analogues of fprintf and vfprintf, except that they output to
       a file descriptor fd instead of to a given stream.

NOTES
       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 function in programs intended to be portable.

       A better name would have been fdprintf.

SEE ALSO
       printf(3)

GNU
								    2001-12-18								DPRINTF(3)