VFPRINTF(3)                POSIX Programmer's Manual               VFPRINTF(3)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.


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.1-2008
       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.1-2008, <stdarg.h>, <stdio.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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 .



IEEE/The Open Group                  2013                          VFPRINTF(3)
