/* $OpenBSD: refill.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <errno.h> #include <stdio.h> #include <stdlib.h> #include "local.h" static int lflush(FILE *fp) { if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) return (__sflush_locked(fp)); /* ignored... */ return (0); } /* * Refill a stdio buffer. * Return EOF on eof or error, 0 otherwise. */ int __srefill(FILE *fp) { /* make sure stdio is set up */ if (!__sdidinit) __sinit(); 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) { errno = EBADF; fp->_flags |= __SERR; return (EOF); } /* switch to reading */ if (fp->_flags & __SWR) { if (__sflush(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(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 to avoid potential deadlock. */ fp->_flags |= __SIGN; (void) _fwalk(lflush); fp->_flags &= ~__SIGN; /* 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); fp->_flags &= ~__SMOD; /* buffer contents are again pristine */ if (fp->_r <= 0) { if (fp->_r == 0) fp->_flags |= __SEOF; else { fp->_r = 0; fp->_flags |= __SERR; } return (EOF); } return (0); }