This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       Applications using these functions should call va_end(ap) afterwards to clean up.

       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 .

IEEE/The Open Group                                   2017                                      VFPRINTF(3POSIX)

       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.

       Refer to fprintf().

       Thefollowingsectionsareinformative.

       None.

       None.

       vdprintf, vfprintf, vprintf, vsnprintf, vsprintf — format output of a stdarg argument list

       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.

       None.

       Refer to fprintf().

Section2.5, StandardI/OStreams, fprintf()

       The Base Definitions volume of POSIX.1‐2017, <stdarg.h>, <stdio.h>

       #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);