lib/libc/stdio/fgetstr.c

   1 /* $NetBSD: fgetstr.c,v 1.9 2009/12/01 00:03:53 roy Exp $       */
   2
   3 /*
   4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
   5  *
   6  * This code is derived from software contributed to The NetBSD Foundation
   7  * by Roy Marples.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __RCSID("$NetBSD: fgetstr.c,v 1.9 2009/12/01 00:03:53 roy Exp $");
  32
  33 #include "namespace.h"
  34
  35 #include <assert.h>
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <stdio.h>
  39
  40 #include "reentrant.h"
  41 #include "local.h"
  42
  43 /*
  44  * Get an input line.
  45  * This now uses getdelim(3) for a code reduction.
  46  * The upside is that strings are now always NULL terminated, but relying
  47  * on this is non portable - better to use the POSIX getdelim(3) function.
  48  */
  49 char *
  50 __fgetstr(FILE *__restrict fp, size_t *__restrict lenp, int sep)
  51 {
  52         char *p;
  53         size_t size;
  54         ssize_t n;
  55
  56         _DIAGASSERT(fp != NULL);
  57         _DIAGASSERT(lenp != NULL);
  58
  59         p = (char *)fp->_lb._base;
  60         size = fp->_lb._size;
  61         n = __getdelim(&p, &size, sep, fp);
  62         fp->_lb._base = (unsigned char *)p;
  63         /* The struct size variable is only an int .....
  64          * This still works when exceeded, but the buffer could be
  65          * realloced needlessly. */
  66         if (size > INT_MAX)
  67                 fp->_lb._size = INT_MAX;
  68         else
  69                 fp->_lb._size = (int)size;
  70         if (n == -1) {
  71                 *lenp = 0;
  72                 if (__sferror(fp) && errno == EOVERFLOW) /* fixup errno */
  73                         errno = EINVAL;
  74                 return NULL;
  75         }
  76         *lenp = n;
  77         return p;
  78 }