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 .