lib/libc/stdio/fgetwln.c

   1 /*      $NetBSD: fgetwln.c,v 1.2 2009/01/31 06:08:28 lukem Exp $        */
   2
   3 /*-
   4  * Copyright (c) 2002-2004 Tim J. Robbins.
   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
  29 #include <sys/cdefs.h>
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 #if 0
  32 __FBSDID("$FreeBSD: src/lib/libc/stdio/fgetwln.c,v 1.2 2004/08/06 17:00:09 tjr Exp $");
  33 #else
  34 __RCSID("$NetBSD: fgetwln.c,v 1.2 2009/01/31 06:08:28 lukem Exp $");
  35 #endif
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #include "namespace.h"
  39 #include <assert.h>
  40 #include <errno.h>
  41 #include <limits.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <wchar.h>
  45 #include "reentrant.h"
  46 #include "local.h"
  47
  48 #ifdef __weak_alias
  49 __weak_alias(fgetwln,_fgetwln)
  50 #endif
  51
  52 /*
  53  * Expand the line buffer.  Return -1 on error.
  54 #ifdef notdef
  55  * The `new size' does not account for a terminating '\0',
  56  * so we add 1 here.
  57 #endif
  58  */
  59 static int
  60 __slbexpand(FILE *fp, size_t newsize)
  61 {
  62         void *p;
  63
  64 #ifdef notdef
  65         ++newsize;
  66 #endif
  67         _DIAGASSERT(fp != NULL);
  68
  69         /* fp->_lb._size is an int ..... */
  70         if (newsize > INT_MAX) {
  71                 errno = EOVERFLOW;
  72                 return (-1);
  73         }
  74         if ((size_t)fp->_lb._size >= newsize)
  75                 return (0);
  76         if ((p = realloc(fp->_lb._base, newsize)) == NULL)
  77                 return (-1);
  78         fp->_lb._base = p;
  79         fp->_lb._size = newsize;
  80         return (0);
  81 }
  82
  83 wchar_t *
  84 fgetwln(FILE * __restrict fp, size_t *lenp)
  85 {
  86         wint_t wc;
  87         size_t len;
  88
  89         FLOCKFILE(fp);
  90         _SET_ORIENTATION(fp, 1);
  91
  92         len = 0;
  93         while ((wc = __fgetwc_unlock(fp)) != WEOF) {
  94 #define GROW    512
  95                 if (len * sizeof(wchar_t) >= (size_t)fp->_lb._size &&
  96                     __slbexpand(fp, (len + GROW) * sizeof(wchar_t)))
  97                         goto error;
  98                 *((wchar_t *)(void *)fp->_lb._base + len++) = wc;
  99                 if (wc == L'\n')
 100                         break;
 101         }
 102         if (len == 0)
 103                 goto error;
 104
 105         FUNLOCKFILE(fp);
 106         *lenp = len;
 107         return ((wchar_t *)(void *)fp->_lb._base);
 108
 109 error:
 110         FUNLOCKFILE(fp);
 111         *lenp = 0;
 112         return (NULL);
 113 }