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 <sys/cdefs.h> 32 #if defined(LIBC_SCCS) && !defined(lint) 33 __RCSID("$NetBSD: ungetwc.c,v 1.3 2005/06/12 05:21:27 lukem Exp $"); 34 #endif /* LIBC_SCCS and not lint */ 35 36 #include <assert.h> 37 #include <errno.h> 38 #include <stdio.h> 39 #include <wchar.h> 40 #include "reentrant.h" 41 #include "local.h" 42 43 wint_t 44 ungetwc(wint_t wc, FILE *fp) 45 { 46 struct wchar_io_data *wcio; 47 48 _DIAGASSERT(fp); 49 50 if (wc == WEOF) 51 return WEOF; 52 53 FLOCKFILE(fp); 54 _SET_ORIENTATION(fp, 1); 55 /* 56 * XXX since we have no way to transform a wchar string to 57 * a char string in reverse order, we can't use ungetc. 58 */ 59 /* XXX should we flush ungetc buffer? */ 60 61 wcio = WCIO_GET(fp); 62 if (wcio == 0) { 63 FUNLOCKFILE(fp); 64 errno = ENOMEM; /* XXX */ 65 return WEOF; 66 } 67 68 if (wcio->wcio_ungetwc_inbuf >= WCIO_UNGETWC_BUFSIZE) { 69 FUNLOCKFILE(fp); 70 return WEOF; 71 } 72 73 wcio->wcio_ungetwc_buf[wcio->wcio_ungetwc_inbuf++] = wc; 74 __sclearerr(fp); 75 FUNLOCKFILE(fp); 76 77 return wc; 78 } 79