xref: /freebsd/lib/libc/stdio/fgetwc.c (revision fcc51917875e7f6d7d620c6a3e8268dcc6306baf)
1e74101e4STim J. Robbins /*-
287275e43STim J. Robbins  * Copyright (c) 2002-2004 Tim J. Robbins.
3e74101e4STim J. Robbins  * All rights reserved.
4e74101e4STim J. Robbins  *
5e74101e4STim J. Robbins  * Redistribution and use in source and binary forms, with or without
6e74101e4STim J. Robbins  * modification, are permitted provided that the following conditions
7e74101e4STim J. Robbins  * are met:
8e74101e4STim J. Robbins  * 1. Redistributions of source code must retain the above copyright
9e74101e4STim J. Robbins  *    notice, this list of conditions and the following disclaimer.
10e74101e4STim J. Robbins  * 2. Redistributions in binary form must reproduce the above copyright
11e74101e4STim J. Robbins  *    notice, this list of conditions and the following disclaimer in the
12e74101e4STim J. Robbins  *    documentation and/or other materials provided with the distribution.
13e74101e4STim J. Robbins  *
14e74101e4STim J. Robbins  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15e74101e4STim J. Robbins  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16e74101e4STim J. Robbins  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17e74101e4STim J. Robbins  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18e74101e4STim J. Robbins  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19e74101e4STim J. Robbins  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20e74101e4STim J. Robbins  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21e74101e4STim J. Robbins  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22e74101e4STim J. Robbins  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23e74101e4STim J. Robbins  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24e74101e4STim J. Robbins  * SUCH DAMAGE.
25e74101e4STim J. Robbins  */
26e74101e4STim J. Robbins 
27e74101e4STim J. Robbins #include <sys/cdefs.h>
28e74101e4STim J. Robbins __FBSDID("$FreeBSD$");
29e74101e4STim J. Robbins 
30e74101e4STim J. Robbins #include "namespace.h"
31e74101e4STim J. Robbins #include <errno.h>
32e74101e4STim J. Robbins #include <stdio.h>
3324990dfaSTim J. Robbins #include <stdlib.h>
34e74101e4STim J. Robbins #include <wchar.h>
35e74101e4STim J. Robbins #include "un-namespace.h"
36e74101e4STim J. Robbins #include "libc_private.h"
37e74101e4STim J. Robbins #include "local.h"
38e74101e4STim J. Robbins 
398f030a44STim J. Robbins /*
408f030a44STim J. Robbins  * MT-safe version.
418f030a44STim J. Robbins  */
428f030a44STim J. Robbins wint_t
438f030a44STim J. Robbins fgetwc(FILE *fp)
448f030a44STim J. Robbins {
458f030a44STim J. Robbins 	wint_t r;
468f030a44STim J. Robbins 
478f030a44STim J. Robbins 	FLOCKFILE(fp);
488f030a44STim J. Robbins 	ORIENT(fp, 1);
498f030a44STim J. Robbins 	r = __fgetwc(fp);
508f030a44STim J. Robbins 	FUNLOCKFILE(fp);
518f030a44STim J. Robbins 
528f030a44STim J. Robbins 	return (r);
538f030a44STim J. Robbins }
548f030a44STim J. Robbins 
55fcc51917STim J. Robbins /*
56fcc51917STim J. Robbins  * Non-MT-safe version.
57fcc51917STim J. Robbins  */
58fcc51917STim J. Robbins wint_t
59fcc51917STim J. Robbins __fgetwc(FILE *fp)
600b7bc802STim J. Robbins {
6124990dfaSTim J. Robbins 	wchar_t wc;
62d6ed810aSTim J. Robbins 	size_t nconv;
63e74101e4STim J. Robbins 
64d6ed810aSTim J. Robbins 	if (fp->_r <= 0 && __srefill(fp))
6524990dfaSTim J. Robbins 		return (WEOF);
66fcc51917STim J. Robbins 	if (MB_CUR_MAX == 1) {
67fcc51917STim J. Robbins 		/* Fast path for single-byte encodings. */
68fcc51917STim J. Robbins 		wc = *fp->_p++;
69fcc51917STim J. Robbins 		fp->_r--;
70fcc51917STim J. Robbins 		return (wc);
71fcc51917STim J. Robbins 	}
72d6ed810aSTim J. Robbins 	do {
73d6ed810aSTim J. Robbins 		nconv = mbrtowc(&wc, fp->_p, fp->_r, &fp->_extra->mbstate);
74d6ed810aSTim J. Robbins 		if (nconv == (size_t)-1)
7524990dfaSTim J. Robbins 			break;
76d6ed810aSTim J. Robbins 		else if (nconv == (size_t)-2)
7787275e43STim J. Robbins 			continue;
78d6ed810aSTim J. Robbins 		else if (nconv == 0) {
79d6ed810aSTim J. Robbins 			/*
80d6ed810aSTim J. Robbins 			 * Assume that the only valid representation of
81d6ed810aSTim J. Robbins 			 * the null wide character is a single null byte.
82d6ed810aSTim J. Robbins 			 */
83d6ed810aSTim J. Robbins 			fp->_p++;
84d6ed810aSTim J. Robbins 			fp->_r--;
8587275e43STim J. Robbins 			return (L'\0');
86d6ed810aSTim J. Robbins 		} else {
87d6ed810aSTim J. Robbins 			fp->_p += nconv;
88d6ed810aSTim J. Robbins 			fp->_r -= nconv;
8987275e43STim J. Robbins 			return (wc);
9024990dfaSTim J. Robbins 		}
91d6ed810aSTim J. Robbins 	} while (__srefill(fp) == 0);
926180233fSTim J. Robbins 	fp->_flags |= __SERR;
9387275e43STim J. Robbins 	errno = EILSEQ;
9424990dfaSTim J. Robbins 	return (WEOF);
95e74101e4STim J. Robbins }
96