snprintf.c

来自「用于嵌入式Linux系统的标准C的库函数」· C语言 代码 · 共 96 行

/* doc in sprintf.c */

/* This code created by modifying sprintf.c so copyright inherited. */

/*
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <stdio.h>
#ifdef _HAVE_STDC
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include <limits.h>
#include <_ansi.h>
#include "local.h"

int
#ifdef _HAVE_STDC
_DEFUN (_snprintf_r, (ptr, str, size, fmt), struct _reent *ptr _AND char *str _AND size_t size _AND _CONST char *fmt _DOTS)
#else
_snprintf_r (ptr, str, size, fmt, va_alist)
     struct _reent *ptr;
     char *str;
     size_t size;
     _CONST char *fmt;
     va_dcl
#endif
{
  int ret;
  va_list ap;
  FILE f;

  f._flags = __SWR | __SSTR;
  f._bf._base = f._p = (unsigned char *) str;
  f._bf._size = f._w = (size > 0 ? size - 1 : 0);
#ifdef _HAVE_STDC
  va_start (ap, fmt);
#else
  va_start (ap);
#endif
  ret = _vfprintf_r (ptr, &f, fmt, ap);
  va_end (ap);
  if (size > 0)
    *f._p = 0;
  return (ret);
}

#ifndef _REENT_ONLY

int
#ifdef _HAVE_STDC
_DEFUN (snprintf, (str, size, fmt), char *str _AND size_t size _AND _CONST char *fmt _DOTS)
#else
snprintf (str, size, fmt, va_alist)
     char *str;
     size_t size;
     _CONST char *fmt;
     va_dcl
#endif
{
  int ret;
  va_list ap;
  FILE f;

  f._flags = __SWR | __SSTR;
  f._bf._base = f._p = (unsigned char *) str;
  f._bf._size = f._w = (size > 0 ? size - 1 : 0);
#ifdef _HAVE_STDC
  va_start (ap, fmt);
#else
  va_start (ap);
#endif
  ret = _vfprintf_r (_REENT, &f, fmt, ap);
  va_end (ap);
  if (size > 0)
    *f._p = 0;
  return (ret);
}

#endif