| 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 | * 4. Neither the name of the University nor the names of its contributors␊ |
| 17 | * may be used to endorse or promote products derived from this software␊ |
| 18 | * without specific prior written permission.␊ |
| 19 | *␊ |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND␊ |
| 21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE␊ |
| 22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE␊ |
| 23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE␊ |
| 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL␊ |
| 25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS␊ |
| 26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)␊ |
| 27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT␊ |
| 28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY␊ |
| 29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF␊ |
| 30 | * SUCH DAMAGE.␊ |
| 31 | */␊ |
| 32 | ␊ |
| 33 | #if defined(LIBC_SCCS) && !defined(lint)␊ |
| 34 | static char sccsid[] = "@(#)refill.c␉8.1 (Berkeley) 6/4/93";␊ |
| 35 | #endif /* LIBC_SCCS and not lint */␊ |
| 36 | #include <sys/cdefs.h>␊ |
| 37 | __FBSDID("$FreeBSD: src/lib/libc/stdio/refill.c,v 1.20 2008/04/17 22:17:54 jhb Exp $");␊ |
| 38 | ␊ |
| 39 | #include "namespace.h"␊ |
| 40 | #include <errno.h>␊ |
| 41 | #include <stdio.h>␊ |
| 42 | #include <stdlib.h>␊ |
| 43 | #include "un-namespace.h"␊ |
| 44 | ␊ |
| 45 | ␊ |
| 46 | #include "local.h"␊ |
| 47 | ␊ |
| 48 | static int lflush(FILE *);␊ |
| 49 | ␊ |
| 50 | static int␊ |
| 51 | lflush(FILE *fp)␊ |
| 52 | {␊ |
| 53 | ␉int␉ret = 0;␊ |
| 54 | ␊ |
| 55 | ␉if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) {␊ |
| 56 | ␉␉ret = __sflush(fp);␊ |
| 57 | ␉}␊ |
| 58 | ␉return (ret);␊ |
| 59 | }␊ |
| 60 | ␊ |
| 61 | /*␊ |
| 62 | * Refill a stdio buffer.␊ |
| 63 | * Return EOF on eof or error, 0 otherwise.␊ |
| 64 | */␊ |
| 65 | __private_extern__ int␊ |
| 66 | __srefill0(FILE *fp)␊ |
| 67 | {␊ |
| 68 | ␊ |
| 69 | ␉/* make sure stdio is set up */␊ |
| 70 | ␉if (!__sdidinit)␊ |
| 71 | ␉␉__sinit();␊ |
| 72 | ␊ |
| 73 | ␉ORIENT(fp, -1);␊ |
| 74 | ␊ |
| 75 | ␉fp->_r = 0;␉␉/* largely a convenience for callers */␊ |
| 76 | ␊ |
| 77 | ␉/* SysV does not make this test; take it out for compatibility */␊ |
| 78 | ␉if (fp->_flags & __SEOF)␊ |
| 79 | ␉␉return (EOF);␊ |
| 80 | ␊ |
| 81 | ␉/* if not already reading, have to be reading and writing */␊ |
| 82 | ␉if ((fp->_flags & __SRD) == 0) {␊ |
| 83 | ␉␉if ((fp->_flags & __SRW) == 0) {␊ |
| 84 | ␉␉␉errno = EBADF;␊ |
| 85 | ␉␉␉fp->_flags |= __SERR;␊ |
| 86 | ␉␉␉return (EOF);␊ |
| 87 | ␉␉}␊ |
| 88 | ␉␉/* switch to reading */␊ |
| 89 | ␉␉if (fp->_flags & __SWR) {␊ |
| 90 | ␉␉␉if (__sflush(fp))␊ |
| 91 | ␉␉␉␉return (EOF);␊ |
| 92 | ␉␉␉fp->_flags &= ~__SWR;␊ |
| 93 | ␉␉␉fp->_w = 0;␊ |
| 94 | ␉␉␉fp->_lbfsize = 0;␊ |
| 95 | ␉␉}␊ |
| 96 | ␉␉fp->_flags |= __SRD;␊ |
| 97 | ␉} else {␊ |
| 98 | ␉␉/*␊ |
| 99 | ␉␉ * We were reading. If there is an ungetc buffer,␊ |
| 100 | ␉␉ * we must have been reading from that. Drop it,␊ |
| 101 | ␉␉ * restoring the previous buffer (if any). If there␊ |
| 102 | ␉␉ * is anything in that buffer, return.␊ |
| 103 | ␉␉ */␊ |
| 104 | ␉␉if (HASUB(fp)) {␊ |
| 105 | ␉␉␉FREEUB(fp);␊ |
| 106 | ␉␉␉if ((fp->_r = fp->_ur) != 0) {␊ |
| 107 | ␉␉␉␉fp->_p = fp->_up;␊ |
| 108 | ␉␉␉␉return (0);␊ |
| 109 | ␉␉␉}␊ |
| 110 | ␉␉}␊ |
| 111 | ␉}␊ |
| 112 | ␊ |
| 113 | ␉if (fp->_bf._base == NULL)␊ |
| 114 | ␉␉__smakebuf(fp);␊ |
| 115 | ␊ |
| 116 | ␉/*␊ |
| 117 | ␉ * Before reading from a line buffered or unbuffered file,␊ |
| 118 | ␉ * flush all line buffered output files, per the ANSI C␊ |
| 119 | ␉ * standard.␊ |
| 120 | ␉ */␊ |
| 121 | ␉if (fp->_flags & (__SLBF|__SNBF)) {␊ |
| 122 | ␉␉/* Ignore this file in _fwalk to avoid potential deadlock. */␊ |
| 123 | ␉␉fp->_flags |= __SIGN;␊ |
| 124 | ␉␉(void) _fwalk(lflush);␊ |
| 125 | ␉␉fp->_flags &= ~__SIGN;␊ |
| 126 | ␊ |
| 127 | ␉␉/* Now flush this file without locking it. */␊ |
| 128 | ␉␉if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))␊ |
| 129 | ␉␉␉__sflush(fp);␊ |
| 130 | ␉}␊ |
| 131 | ␉return (1);␊ |
| 132 | }␊ |
| 133 | ␊ |
| 134 | __private_extern__ int␊ |
| 135 | __srefill1(FILE *fp)␊ |
| 136 | {␊ |
| 137 | ␊ |
| 138 | ␉fp->_p = fp->_bf._base;␊ |
| 139 | ␉fp->_r = _sread(fp, (char *)fp->_p, fp->_bf._size);␊ |
| 140 | ␉fp->_flags &= ~__SMOD;␉/* buffer contents are again pristine */␊ |
| 141 | ␉if (fp->_r <= 0) {␊ |
| 142 | ␉␉if (fp->_r == 0)␊ |
| 143 | ␉␉␉fp->_flags |= __SEOF;␊ |
| 144 | ␉␉else {␊ |
| 145 | ␉␉␉fp->_r = 0;␊ |
| 146 | ␉␉␉fp->_flags |= __SERR;␊ |
| 147 | ␉␉}␊ |
| 148 | ␉␉return (EOF);␊ |
| 149 | ␉}␊ |
| 150 | ␉return (0);␊ |
| 151 | }␊ |
| 152 | ␊ |
| 153 | int␊ |
| 154 | __srefill(FILE *fp)␊ |
| 155 | {␊ |
| 156 | ␉int ret;␊ |
| 157 | ␊ |
| 158 | ␉if ((ret = __srefill0(fp)) <= 0)␊ |
| 159 | ␉␉return ret;␊ |
| 160 | ␉return __srefill1(fp);␊ |
| 161 | }␊ |
| 162 | |
