stdio/FreeBSD/fgetws.c

   1 /*-
   2  * Copyright (c) 2002-2004 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: src/lib/libc/stdio/fgetws.c,v 1.6 2004/10/03 15:48:32 stefanf Exp $");
  29
  30 #include "namespace.h"
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <wchar.h>
  35 #include "un-namespace.h"
  36 #include "libc_private.h"
  37 #include "local.h"
  38 #include "mblocal.h"
  39
  40 wchar_t *
  41 fgetws(wchar_t * __restrict ws, int n, FILE * __restrict fp)
  42 {
  43         wchar_t *wsp;
  44         size_t nconv;
  45         const char *src;
  46         unsigned char *nl;
  47
  48         FLOCKFILE(fp);
  49         ORIENT(fp, 1);
  50
  51         if (n <= 0) {
  52                 errno = EINVAL;
  53                 goto error;
  54         }
  55
  56         if (fp->_r <= 0 && __srefill(fp))
  57                 /* EOF */
  58                 goto error;
  59         wsp = ws;
  60         do {
  61                 src = fp->_p;
  62                 nl = memchr(fp->_p, '\n', fp->_r);
  63                 nconv = __mbsnrtowcs(wsp, &src,
  64                     nl != NULL ? (nl - fp->_p + 1) : fp->_r,
  65                     n - 1, &fp->_extra->mbstate);
  66                 if (nconv == (size_t)-1)
  67                         /* Conversion error */
  68                         goto error;
  69                 if (src == NULL) {
  70                         /*
  71                          * We hit a null byte. Increment the character count,
  72                          * since mbsnrtowcs()'s return value doesn't include
  73                          * the terminating null, then resume conversion
  74                          * after the null.
  75                          */
  76                         nconv++;
  77                         src = memchr(fp->_p, '\0', fp->_r);
  78                         src++;
  79                 }
  80                 fp->_r -= (unsigned char *)src - fp->_p;
  81                 fp->_p = (unsigned char *)src;
  82                 n -= nconv;
  83                 wsp += nconv;
  84         } while (wsp[-1] != L'\n' && n > 1 && (fp->_r > 0 ||
  85             __srefill(fp) == 0));
  86         if (wsp == ws)
  87                 /* EOF */
  88                 goto error;
  89         if (!__mbsinit(&fp->_extra->mbstate))
  90                 /* Incomplete character */
  91                 goto error;
  92         *wsp++ = L'\0';
  93         FUNLOCKFILE(fp);
  94
  95         return (ws);
  96
  97 error:
  98         FUNLOCKFILE(fp);
  99         return (NULL);
 100 }