mirror of git://sourceware.org/git/glibc.git
136 lines
3.5 KiB
C
136 lines
3.5 KiB
C
/* Copyright (C) 1991, 92, 95, 96, 97, 98 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#define default_func __default_room_functions.__input
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/* Read NMEMB chunks of SIZE bytes each from STREAM into P. */
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size_t
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fread (p, size, nmemb, stream)
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void *p;
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size_t size;
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size_t nmemb;
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register FILE *stream;
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{
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register char *ptr = (char *) p;
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register size_t to_read = size * nmemb;
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size_t bytes = to_read;
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if (!__validfp (stream) || !stream->__mode.__read)
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{
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__set_errno (EINVAL);
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return 0;
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}
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if (feof (stream) || ferror (stream))
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return 0;
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if (p == NULL || to_read == 0)
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return 0;
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if (!stream->__seen || stream->__buffer == NULL || stream->__pushed_back)
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{
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/* This stream has never been seen before, or it has a character
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pushed back. Call __fillbf to deal with those cases. Life will
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be simpler after this call. */
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int c = __fillbf (stream);
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if (c == EOF)
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return 0;
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*ptr++ = c;
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if (--to_read == 0)
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return 1;
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}
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read_from_buffer:;
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if (stream->__bufp < stream->__get_limit)
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{
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/* First off, empty out the buffer. */
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register size_t copy = stream->__get_limit - stream->__bufp;
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if (copy > to_read)
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copy = to_read;
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to_read -= copy;
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if (copy > 20)
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memcpy((void *) ptr, (void *) stream->__bufp, copy);
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else
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{
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register size_t i;
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for (i = 0; i < copy; ++i)
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ptr[i] = stream->__bufp[i];
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}
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stream->__bufp += copy;
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if (to_read == 0)
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return nmemb;
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ptr += copy;
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}
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/* Reading directly into the user's buffer doesn't help when
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using a user-specified input buffer filling/expanding function,
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so we don't do it in that case. */
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if (to_read >= stream->__bufsize &&
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stream->__room_funcs.__input == default_func &&
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stream->__offset == stream->__target)
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{
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/* Read directly into the user's buffer. */
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if (stream->__io_funcs.__read != NULL)
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while (to_read > 0)
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{
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register int count;
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count = (*stream->__io_funcs.__read) (stream->__cookie,
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ptr, to_read);
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if (count > 0)
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{
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to_read -= count;
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if (stream->__offset != -1)
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{
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stream->__offset += count;
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stream->__target += count;
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}
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ptr += count;
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}
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else if (count == 0)
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{
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stream->__eof = 1;
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break;
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}
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else
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{
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stream->__error = 1;
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break;
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}
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}
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else
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stream->__eof = 1;
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}
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else
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{
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int c = __fillbf (stream);
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if (c == EOF)
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return (bytes - to_read) / size;
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*ptr++ = (char) c;
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--to_read;
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if (to_read > 0)
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goto read_from_buffer;
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}
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return (bytes - to_read) / size;
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}
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weak_alias (fread, fread_unlocked)
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