VFPRINTF
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
vdprintf,
vfprintf,
vprintf,
vsnprintf,
vsprintf
--- format output of a stdarg argument list
SYNOPSIS
#include <stdarg.h>
#include <stdio.h>
int vdprintf(int fildes, const char *restrict format, va_list ap);
int vfprintf(FILE *restrict stream, const char *restrict format,
va_list ap);
int vprintf(const char *restrict format, va_list ap);
int vsnprintf(char *restrict s, size_t n, const char *restrict format,
va_list ap);
int vsprintf(char *restrict s, const char *restrict format, va_list ap);
DESCRIPTION
The functionality described on this reference page is aligned with the
ISO C standard. Any conflict between the requirements described here and the
ISO C standard is unintentional. This volume of POSIX.1-2017 defers to the ISO C standard.
The
vdprintf(),
vfprintf(),
vprintf(),
vsnprintf(),
and
vsprintf()
functions shall be equivalent to the
dprintf(),
fprintf(),
printf(),
snprintf(),
and
sprintf()
functions respectively, except that instead of being called with a
variable number of arguments, they are called with an argument list as
defined by
<stdarg.h>.
These functions shall not invoke the
va_end
macro. As these functions invoke the
va_arg
macro, the value of
ap
after the return is unspecified.
RETURN VALUE
Refer to
fprintf().
ERRORS
Refer to
fprintf().
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
Applications using these functions should call
va_end(
ap)
afterwards to clean up.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
Section 2.5,
Standard I/O Streams,
fprintf()
The Base Definitions volume of POSIX.1-2017,
<stdarg.h>,
<stdio.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .