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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,
* and/or 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.
*/
/* No user fns here. Pesch 15apr92. */
#define _DEFAULT_SOURCE
#include <_ansi.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "local.h"
static int
lflush (FILE *fp)
{
if ((fp->_flags & (__SLBF | __SWR)) == (__SLBF | __SWR))
return fflush ( fp);
return 0;
}
/*
* Refill a stdio buffer.
* Return EOF on eof or error, 0 otherwise.
*/
int
_srefill (
register FILE * fp)
{
/* make sure stdio is set up */
CHECK_INIT (ptr, fp);
ORIENT (fp, -1);
fp->_r = 0; /* largely a convenience for callers */
/* SysV does not make this test; take it out for compatibility */
if (fp->_flags & __SEOF)
return EOF;
/* if not already reading, have to be reading and writing */
if ((fp->_flags & __SRD) == 0)
{
if ((fp->_flags & __SRW) == 0)
{
_REENT_ERRNO(ptr) = EBADF;
fp->_flags |= __SERR;
return EOF;
}
/* switch to reading */
if (fp->_flags & __SWR)
{
if (fflush ( fp))
return EOF;
fp->_flags &= ~__SWR;
fp->_w = 0;
fp->_lbfsize = 0;
}
fp->_flags |= __SRD;
}
else
{
/*
* We were reading. If there is an ungetc buffer,
* we must have been reading from that. Drop it,
* restoring the previous buffer (if any). If there
* is anything in that buffer, return.
*/
if (HASUB (fp))
{
FREEUB (ptr, fp);
if ((fp->_r = fp->_ur) != 0)
{
fp->_p = fp->_up;
return 0;
}
}
}
if (fp->_bf._base == NULL)
_smakebuf ( fp);
/*
* Before reading from a line buffered or unbuffered file,
* flush all line buffered output files, per the ANSI C
* standard.
*/
if (fp->_flags & (__SLBF | __SNBF))
{
/* Ignore this file in _fwalk_sglue to avoid potential deadlock. */
short orig_flags = fp->_flags;
fp->_flags = 1;
(void) _fwalk_sglue (lflush, &__sglue);
fp->_flags = orig_flags;
/* Now flush this file without locking it. */
if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
_sflush ( fp);
}
fp->_p = fp->_bf._base;
fp->_r = fp->_read (fp->_cookie, (char *) fp->_p, fp->_bf._size);
if (fp->_r <= 0)
{
if (fp->_r == 0)
fp->_flags |= __SEOF;
else
{
fp->_r = 0;
fp->_flags |= __SERR;
}
return EOF;
}
return 0;
}
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