1 /* $OpenBSD: ungetwc.c,v 1.1 2005/06/17 20:40:32 espie Exp $ */ 2 /* $NetBSD: ungetwc.c,v 1.2 2003/01/18 11:29:59 thorpej Exp $ */ 3 4 /*- 5 * Copyright (c)2001 Citrus Project, 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $Citrus$ 30 */ 31 32 #include <errno.h> 33 #include <stdio.h> 34 #include <wchar.h> 35 #include "local.h" 36 37 wint_t 38 ungetwc(wint_t wc, FILE *fp) 39 { 40 struct wchar_io_data *wcio; 41 42 if (wc == WEOF) 43 return WEOF; 44 45 flockfile(fp); 46 _SET_ORIENTATION(fp, 1); 47 /* 48 * XXX since we have no way to transform a wchar string to 49 * a char string in reverse order, we can't use ungetc. 50 */ 51 /* XXX should we flush ungetc buffer? */ 52 53 wcio = WCIO_GET(fp); 54 if (wcio == 0) { 55 funlockfile(fp); 56 errno = ENOMEM; /* XXX */ 57 return WEOF; 58 } 59 60 if (wcio->wcio_ungetwc_inbuf >= WCIO_UNGETWC_BUFSIZE) { 61 funlockfile(fp); 62 return WEOF; 63 } 64 65 wcio->wcio_ungetwc_buf[wcio->wcio_ungetwc_inbuf++] = wc; 66 __sclearerr(fp); 67 funlockfile(fp); 68 69 return wc; 70 } 71