vx32

Local 9vx git repository for patches.
git clone git://r-36.net/vx32
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refill.c (3882B)

      1 /*-
      2  * Copyright (c) 1990, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Chris Torek.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 static char rcsid[] = "$OpenBSD: refill.c,v 1.3 1996/08/19 08:33:00 tholo Exp $";
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include <errno.h>
     42 #include <stdio.h>
     43 #include <stdlib.h>
     44 #include "local.h"
     45 
     46 static int
     47 lflush(fp)
     48 	FILE *fp;
     49 {
     50 
     51 	if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
     52 		return (__sflush(fp));
     53 	return (0);
     54 }
     55 
     56 /*
     57  * Refill a stdio buffer.
     58  * Return EOF on eof or error, 0 otherwise.
     59  */
     60 int
     61 __srefill(fp)
     62 	register FILE *fp;
     63 {
     64 
     65 	/* make sure stdio is set up */
     66 	if (!__sdidinit)
     67 		__sinit();
     68 
     69 	fp->_r = 0;		/* largely a convenience for callers */
     70 
     71 	/* SysV does not make this test; take it out for compatibility */
     72 	if (fp->_flags & __SEOF)
     73 		return (EOF);
     74 
     75 	/* if not already reading, have to be reading and writing */
     76 	if ((fp->_flags & __SRD) == 0) {
     77 		if ((fp->_flags & __SRW) == 0) {
     78 			errno = EBADF;
     79 			return (EOF);
     80 		}
     81 		/* switch to reading */
     82 		if (fp->_flags & __SWR) {
     83 			if (__sflush(fp))
     84 				return (EOF);
     85 			fp->_flags &= ~__SWR;
     86 			fp->_w = 0;
     87 			fp->_lbfsize = 0;
     88 		}
     89 		fp->_flags |= __SRD;
     90 	} else {
     91 		/*
     92 		 * We were reading.  If there is an ungetc buffer,
     93 		 * we must have been reading from that.  Drop it,
     94 		 * restoring the previous buffer (if any).  If there
     95 		 * is anything in that buffer, return.
     96 		 */
     97 		if (HASUB(fp)) {
     98 			FREEUB(fp);
     99 			if ((fp->_r = fp->_ur) != 0) {
    100 				fp->_p = fp->_up;
    101 				return (0);
    102 			}
    103 		}
    104 	}
    105 
    106 	if (fp->_bf._base == NULL)
    107 		__smakebuf(fp);
    108 
    109 	/*
    110 	 * Before reading from a line buffered or unbuffered file,
    111 	 * flush all line buffered output files, per the ANSI C
    112 	 * standard.
    113 	 */
    114 	if (fp->_flags & (__SLBF|__SNBF))
    115 		(void) _fwalk(lflush);
    116 	fp->_p = fp->_bf._base;
    117 	fp->_r = (*fp->_read)(fp->_cookie, (char *)fp->_p, fp->_bf._size);
    118 	fp->_flags &= ~__SMOD;	/* buffer contents are again pristine */
    119 	if (fp->_r <= 0) {
    120 		if (fp->_r == 0)
    121 			fp->_flags |= __SEOF;
    122 		else {
    123 			fp->_r = 0;
    124 			fp->_flags |= __SERR;
    125 		}
    126 		return (EOF);
    127 	}
    128 	return (0);
    129 }