Annotation of prex-old/usr/lib/libc/stdio/refill.c, Revision 1.1
1.1 ! nbrk 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. 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: #include <errno.h>
! 34: #include <stdio.h>
! 35: #include <stdlib.h>
! 36: #include "local.h"
! 37:
! 38: static int
! 39: lflush(FILE *fp)
! 40: {
! 41:
! 42: if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
! 43: return (__sflush(fp));
! 44: return (0);
! 45: }
! 46:
! 47: /*
! 48: * Refill a stdio buffer.
! 49: * Return EOF on eof or error, 0 otherwise.
! 50: */
! 51: int
! 52: __srefill(fp)
! 53: FILE *fp;
! 54: {
! 55:
! 56: /* make sure stdio is set up */
! 57: if (!__sdidinit)
! 58: __sinit();
! 59:
! 60: fp->_r = 0; /* largely a convenience for callers */
! 61:
! 62: /* SysV does not make this test; take it out for compatibility */
! 63: if (fp->_flags & __SEOF)
! 64: return (EOF);
! 65:
! 66: /* if not already reading, have to be reading and writing */
! 67: if ((fp->_flags & __SRD) == 0) {
! 68: if ((fp->_flags & __SRW) == 0) {
! 69: errno = EBADF;
! 70: return (EOF);
! 71: }
! 72: /* switch to reading */
! 73: if (fp->_flags & __SWR) {
! 74: if (__sflush(fp))
! 75: return (EOF);
! 76: fp->_flags &= ~__SWR;
! 77: fp->_w = 0;
! 78: }
! 79: fp->_flags |= __SRD;
! 80: } else {
! 81: /*
! 82: * We were reading. If there is an ungetc buffer,
! 83: * we must have been reading from that. Drop it,
! 84: * restoring the previous buffer (if any). If there
! 85: * is anything in that buffer, return.
! 86: */
! 87: if (HASUB(fp)) {
! 88: FREEUB(fp);
! 89: if ((fp->_r = fp->_ur) != 0) {
! 90: fp->_p = fp->_up;
! 91: return (0);
! 92: }
! 93: }
! 94: }
! 95:
! 96: if (fp->_bf._base == NULL)
! 97: __smakebuf(fp);
! 98:
! 99: /*
! 100: * Before reading from a line buffered or unbuffered file,
! 101: * flush all line buffered output files, per the ANSI C
! 102: * standard.
! 103: */
! 104: if (fp->_flags & (__SLBF|__SNBF))
! 105: (void) _fwalk(lflush);
! 106: fp->_p = fp->_bf._base;
! 107: fp->_r = __sread(fp, (char *)fp->_p, fp->_bf._size);
! 108: if (fp->_r <= 0) {
! 109: if (fp->_r == 0)
! 110: fp->_flags |= __SEOF;
! 111: else {
! 112: fp->_r = 0;
! 113: fp->_flags |= __SERR;
! 114: }
! 115: return (EOF);
! 116: }
! 117: return (0);
! 118: }
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