1 /* $NetBSD: ungetwc.c,v 1.3 2005/06/12 05:21:27 lukem Exp $ */ 2 3 /*- 4 * Copyright (c)2001 Citrus Project, 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $Citrus$ 29 */ 30 31 #include "namespace.h" 32 #include <assert.h> 33 #include <errno.h> 34 #include <stdio.h> 35 #include <wchar.h> 36 #include "un-namespace.h" 37 38 #include "libc_private.h" 39 #include "local.h" 40 #include "priv_stdio.h" 41 42 wint_t 43 ungetwc(wint_t wc, FILE *fp) 44 { 45 struct wchar_io_data *wcio; 46 47 _DIAGASSERT(fp); 48 49 if (wc == WEOF) 50 return WEOF; 51 52 FLOCKFILE(fp); 53 _SET_ORIENTATION(fp, 1); 54 /* 55 * XXX since we have no way to transform a wchar string to 56 * a char string in reverse order, we can't use ungetc. 57 */ 58 /* XXX should we flush ungetc buffer? */ 59 60 wcio = WCIO_GET(fp); 61 if (wcio == NULL) { 62 FUNLOCKFILE(fp); 63 errno = ENOMEM; /* XXX */ 64 return WEOF; 65 } 66 67 if (wcio->wcio_ungetwc_inbuf >= WCIO_UNGETWC_BUFSIZE) { 68 FUNLOCKFILE(fp); 69 return WEOF; 70 } 71 72 wcio->wcio_ungetwc_buf[wcio->wcio_ungetwc_inbuf++] = wc; 73 __sclearerr(fp); 74 FUNLOCKFILE(fp); 75 76 return wc; 77 } 78