snprintf.c   [plain text]

/* Implement the snprintf function.
   Copyright (C) 2003 Free Software Foundation, Inc.
   Written by Kaveh R. Ghazi <>.

This file is part of the libiberty library.  This library is free
software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option)
any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

As a special exception, if you link this library with files
compiled with a GNU compiler to produce an executable, this does not cause
the resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why
the executable file might be covered by the GNU General Public License. */


@deftypefn Supplemental int snprintf (char *@var{buf}, size_t @var{n}, const char *@var{format}, ...)

This function is similar to sprintf, but it will print at most @var{n}
characters.  On error the return value is -1, otherwise it returns the
number of characters that would have been printed had @var{n} been
sufficiently large, regardless of the actual value of @var{n}.  Note
some pre-C99 system libraries do not implement this correctly so users
cannot generally rely on the return value if the system version of
this function is used.

@end deftypefn


#include "ansidecl.h"

#include <stdarg.h>
#include <stddef.h>
#include <varargs.h>
#define size_t unsigned long

int vsnprintf PARAMS ((char *, size_t, const char *, va_list));

snprintf VPARAMS ((char *s, size_t n, const char *format, ...))
  int result;
  VA_OPEN (ap, format);
  VA_FIXEDARG (ap, char *, s);
  VA_FIXEDARG (ap, size_t, n);
  VA_FIXEDARG (ap, const char *, format);
  result = vsnprintf (s, n, format, ap);
  VA_CLOSE (ap);
  return result;