269 lines
6.7 KiB
C
269 lines
6.7 KiB
C
/*
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* Copyright (c) 1990, 2007 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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/*
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FUNCTION
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<<fread>>, <<fread_unlocked>>---read array elements from a file
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INDEX
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fread
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INDEX
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fread_unlocked
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INDEX
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_fread_r
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INDEX
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_fread_unlocked_r
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SYNOPSIS
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#include <stdio.h>
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size_t fread(void *restrict <[buf]>, size_t <[size]>, size_t <[count]>,
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FILE *restrict <[fp]>);
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#define _BSD_SOURCE
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#include <stdio.h>
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size_t fread_unlocked(void *restrict <[buf]>, size_t <[size]>, size_t <[count]>,
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FILE *restrict <[fp]>);
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#include <stdio.h>
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size_t _fread_r(struct _reent *<[ptr]>, void *restrict <[buf]>,
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size_t <[size]>, size_t <[count]>, FILE *restrict <[fp]>);
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#include <stdio.h>
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size_t _fread_unlocked_r(struct _reent *<[ptr]>, void *restrict <[buf]>,
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size_t <[size]>, size_t <[count]>, FILE *restrict <[fp]>);
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DESCRIPTION
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<<fread>> attempts to copy, from the file or stream identified by
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<[fp]>, <[count]> elements (each of size <[size]>) into memory,
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starting at <[buf]>. <<fread>> may copy fewer elements than
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<[count]> if an error, or end of file, intervenes.
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<<fread>> also advances the file position indicator (if any) for
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<[fp]> by the number of @emph{characters} actually read.
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<<fread_unlocked>> is a non-thread-safe version of <<fread>>.
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<<fread_unlocked>> may only safely be used within a scope
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protected by flockfile() (or ftrylockfile()) and funlockfile(). This
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function may safely be used in a multi-threaded program if and only
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if they are called while the invoking thread owns the (FILE *)
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object, as is the case after a successful call to the flockfile() or
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ftrylockfile() functions. If threads are disabled, then
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<<fread_unlocked>> is equivalent to <<fread>>.
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<<_fread_r>> and <<_fread_unlocked_r>> are simply reentrant versions of the
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above that take an additional reentrant structure pointer argument: <[ptr]>.
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RETURNS
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The result of <<fread>> is the number of elements it succeeded in
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reading.
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PORTABILITY
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ANSI C requires <<fread>>.
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<<fread_unlocked>> is a BSD extension also provided by GNU libc.
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Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
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<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
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*/
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#include <_ansi.h>
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#include <stdio.h>
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#include <string.h>
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#include <malloc.h>
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#include "local.h"
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#ifdef __IMPL_UNLOCKED__
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#define _fread_r _fread_unlocked_r
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#define fread fread_unlocked
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#endif
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#ifdef __SCLE
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static size_t
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crlf_r (struct _reent * ptr,
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FILE * fp,
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char * buf,
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size_t count,
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int eof)
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{
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int r;
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char *s, *d, *e;
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if (count == 0)
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return 0;
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e = buf + count;
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for (s=d=buf; s<e-1; s++)
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{
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if (*s == '\r' && s[1] == '\n')
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s++;
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*d++ = *s;
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}
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if (s < e)
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{
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if (*s == '\r')
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{
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int c = __sgetc_raw_r (ptr, fp);
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if (c == '\n')
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*s = '\n';
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else
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ungetc (c, fp);
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}
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*d++ = *s++;
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}
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while (d < e)
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{
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r = _getc_r (ptr, fp);
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if (r == EOF)
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return count - (e-d);
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*d++ = r;
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}
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return count;
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}
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#endif
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size_t
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_fread_r (struct _reent * ptr,
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void *__restrict buf,
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size_t size,
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size_t count,
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FILE * __restrict fp)
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{
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register size_t resid;
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register char *p;
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register int r;
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size_t total;
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if ((resid = count * size) == 0)
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return 0;
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CHECK_INIT(ptr, fp);
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_newlib_flockfile_start (fp);
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ORIENT (fp, -1);
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if (fp->_r < 0)
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fp->_r = 0;
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total = resid;
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p = buf;
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#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
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/* Optimize unbuffered I/O. */
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if (fp->_flags & __SNBF)
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{
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/* First copy any available characters from ungetc buffer. */
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int copy_size = resid > fp->_r ? fp->_r : resid;
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(void) memcpy ((void *) p, (void *) fp->_p, (size_t) copy_size);
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fp->_p += copy_size;
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fp->_r -= copy_size;
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p += copy_size;
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resid -= copy_size;
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/* If still more data needed, free any allocated ungetc buffer. */
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if (HASUB (fp) && resid > 0)
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FREEUB (ptr, fp);
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/* Finally read directly into user's buffer if needed. */
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while (resid > 0)
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{
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int rc = 0;
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/* save fp buffering state */
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void *old_base = fp->_bf._base;
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void * old_p = fp->_p;
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int old_size = fp->_bf._size;
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/* allow __refill to use user's buffer */
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fp->_bf._base = (unsigned char *) p;
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fp->_bf._size = resid;
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fp->_p = (unsigned char *) p;
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rc = __srefill_r (ptr, fp);
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/* restore fp buffering back to original state */
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fp->_bf._base = old_base;
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fp->_bf._size = old_size;
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fp->_p = old_p;
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resid -= fp->_r;
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p += fp->_r;
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fp->_r = 0;
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if (rc)
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{
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#ifdef __SCLE
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if (fp->_flags & __SCLE)
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{
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_newlib_flockfile_exit (fp);
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return crlf_r (ptr, fp, buf, total-resid, 1) / size;
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}
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#endif
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_newlib_flockfile_exit (fp);
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return (total - resid) / size;
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}
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}
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}
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else
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#endif /* !PREFER_SIZE_OVER_SPEED && !__OPTIMIZE_SIZE__ */
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{
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while (resid > (r = fp->_r))
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{
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(void) memcpy ((void *) p, (void *) fp->_p, (size_t) r);
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fp->_p += r;
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/* fp->_r = 0 ... done in __srefill */
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p += r;
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resid -= r;
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if (__srefill_r (ptr, fp))
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{
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/* no more input: return partial result */
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#ifdef __SCLE
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if (fp->_flags & __SCLE)
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{
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_newlib_flockfile_exit (fp);
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return crlf_r (ptr, fp, buf, total-resid, 1) / size;
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}
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#endif
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_newlib_flockfile_exit (fp);
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return (total - resid) / size;
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}
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}
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(void) memcpy ((void *) p, (void *) fp->_p, resid);
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fp->_r -= resid;
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fp->_p += resid;
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}
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/* Perform any CR/LF clean-up if necessary. */
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#ifdef __SCLE
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if (fp->_flags & __SCLE)
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{
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_newlib_flockfile_exit (fp);
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return crlf_r(ptr, fp, buf, total, 0) / size;
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}
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#endif
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_newlib_flockfile_end (fp);
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return count;
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}
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#ifndef _REENT_ONLY
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size_t
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fread (void *__restrict buf,
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size_t size,
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size_t count,
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FILE *__restrict fp)
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{
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return _fread_r (_REENT, buf, size, count, fp);
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}
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#endif
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