flags.c
上传用户:tsgydb
上传日期:2007-04-14
资源大小:10674k
文件大小:3k
- /*-
- * Copyright (c) 1990 The Regents of the University of California.
- * Copyright (c) 1993, 1994 Chris Provenzano.
- * 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. 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.
- */
- #if defined(LIBC_SCCS) && !defined(lint)
- /*static char *sccsid = "from: @(#)flags.c 5.1 (Berkeley) 1/20/91";*/
- static char *rcsid = "$Id$";
- #endif /* LIBC_SCCS and not lint */
- #include <pthread.h>
- #include <sys/types.h>
- #include <stdio.h>
- #include <fcntl.h>
- #include <errno.h>
- #include <unistd.h>
- /*
- * Return the (stdio) flags for a given mode. Store the flags
- * to be passed to an open() syscall through *optr.
- * Return 0 on error.
- */
- __sflags(mode, optr)
- register char *mode;
- int *optr;
- {
- register int ret, m, o;
- switch (*mode++) {
- case 'r': /* open for reading */
- ret = __SRD;
- m = O_RDONLY;
- o = 0;
- break;
- case 'w': /* open for writing */
- ret = __SWR;
- m = O_WRONLY;
- o = O_CREAT | O_TRUNC;
- break;
- case 'a': /* open for appending */
- ret = __SWR;
- m = O_WRONLY;
- o = O_CREAT | O_APPEND;
- break;
- default: /* illegal mode */
- errno = EINVAL;
- return (0);
- }
- /* [rwa]+ or [rwa]b+ means read and write */
- if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) {
- ret = __SRW;
- m = O_RDWR;
- }
- *optr = m | o;
- return (ret);
- }