ungetwc.c revision 103523
1/*- 2 * Copyright (c) 2002 Tim J. Robbins. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/lib/libc/stdio/ungetwc.c 103523 2002-09-18 05:58:11Z tjr $"); 29 30#include "namespace.h" 31#include <errno.h> 32#include <stdio.h> 33#include <stdlib.h> 34#include <wchar.h> 35#include "un-namespace.h" 36#include "libc_private.h" 37#include "local.h" 38 39wint_t 40ungetwc(wint_t wc, FILE *fp) 41{ 42 char buf[MB_LEN_MAX]; 43 mbstate_t mbs; 44 size_t len; 45 46 ORIENTLOCK(fp, 1); 47 48 if (wc == WEOF) 49 return (WEOF); 50 51 memset(&mbs, 0, sizeof(mbs)); 52 if ((len = wcrtomb(buf, wc, &mbs)) == (size_t)-1) 53 return (WEOF); 54 while (len-- != 0) 55 if (ungetc((unsigned char)buf[len], fp) == EOF) 56 return (WEOF); 57 58 return (wc); 59} 60