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/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/*
FUNCTION
<<fread>>---read array elements from a file
INDEX
fread
ANSI_SYNOPSIS
#include <stdio.h>
size_t fread(void *<[buf]>, size_t <[size]>, size_t <[count]>,
FILE *<[fp]>);
TRAD_SYNOPSIS
#include <stdio.h>
size_t fread(<[buf]>, <[size]>, <[count]>, <[fp]>)
char *<[buf]>;
size_t <[size]>;
size_t <[count]>;
FILE *<[fp]>;
DESCRIPTION
<<fread>> attempts to copy, from the file or stream identified by
<[fp]>, <[count]> elements (each of size <[size]>) into memory,
starting at <[buf]>. <<fread>> may copy fewer elements than
<[count]> if an error, or end of file, intervenes.
<<fread>> also advances the file position indicator (if any) for
<[fp]> by the number of @emph{characters} actually read.
RETURNS
The result of <<fread>> is the number of elements it succeeded in
reading.
PORTABILITY
ANSI C requires <<fread>>.
Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
*/
#include <_ansi.h>
#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include "local.h"
#ifdef __SCLE
static size_t
_DEFUN(crlf, (fp, buf, count, eof),
FILE * fp _AND
char * buf _AND
size_t count _AND
int eof)
{
int newcount = 0, r;
char *s, *d, *e;
if (count == 0)
return 0;
e = buf + count;
for (s=d=buf; s<e-1; s++)
{
if (*s == '\r' && s[1] == '\n')
s++;
*d++ = *s;
}
if (s < e)
{
if (*s == '\r')
{
int c = __sgetc_raw (fp);
if (c == '\n')
*s = '\n';
else
ungetc (c, fp);
}
*d++ = *s++;
}
while (d < e)
{
r = getc (fp);
if (r == EOF)
return count - (e-d);
*d++ = r;
}
return count;
}
#endif
size_t
_DEFUN(fread, (buf, size, count, fp),
_PTR buf _AND
size_t size _AND
size_t count _AND
FILE * fp)
{
register size_t resid;
register char *p;
register int r;
size_t total;
if ((resid = count * size) == 0)
return 0;
CHECK_INIT(_REENT);
_flockfile (fp);
if (fp->_r < 0)
fp->_r = 0;
total = resid;
p = buf;
#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
/* Optimize unbuffered I/O. */
if (fp->_flags & __SNBF)
{
/* First copy any available characters from ungetc buffer. */
int copy_size = resid > fp->_r ? fp->_r : resid;
_CAST_VOID memcpy ((_PTR) p, (_PTR) fp->_p, (size_t) copy_size);
fp->_p += copy_size;
fp->_r -= copy_size;
p += copy_size;
resid -= copy_size;
/* If still more data needed, free any allocated ungetc buffer. */
if (HASUB (fp) && resid > 0)
FREEUB (fp);
/* Finally read directly into user's buffer if needed. */
while (resid > 0)
{
int rc = 0;
/* save fp buffering state */
void *old_base = fp->_bf._base;
void * old_p = fp->_p;
int old_size = fp->_bf._size;
/* allow __refill to use user's buffer */
fp->_bf._base = p;
fp->_bf._size = resid;
fp->_p = p;
rc = __srefill (fp);
/* restore fp buffering back to original state */
fp->_bf._base = old_base;
fp->_bf._size = old_size;
fp->_p = old_p;
resid -= fp->_r;
p += fp->_r;
fp->_r = 0;
if (rc)
{
#ifdef __SCLE
if (fp->_flags & __SCLE)
{
_funlockfile (fp);
return crlf (fp, buf, total-resid, 1) / size;
}
#endif
_funlockfile (fp);
return (total - resid) / size;
}
}
}
else
#endif /* !PREFER_SIZE_OVER_SPEED && !__OPTIMIZE_SIZE__ */
{
while (resid > (r = fp->_r))
{
_CAST_VOID memcpy ((_PTR) p, (_PTR) fp->_p, (size_t) r);
fp->_p += r;
/* fp->_r = 0 ... done in __srefill */
p += r;
resid -= r;
if (__srefill (fp))
{
/* no more input: return partial result */
#ifdef __SCLE
if (fp->_flags & __SCLE)
{
_funlockfile (fp);
return crlf (fp, buf, total-resid, 1) / size;
}
#endif
_funlockfile (fp);
return (total - resid) / size;
}
}
_CAST_VOID memcpy ((_PTR) p, (_PTR) fp->_p, resid);
fp->_r -= resid;
fp->_p += resid;
}
/* Perform any CR/LF clean-up if necessary. */
#ifdef __SCLE
if (fp->_flags & __SCLE)
{
_funlockfile (fp);
return crlf(fp, buf, total, 0) / size;
}
#endif
_funlockfile (fp);
return count;
}
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