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 * @(#)flags.c 8.1 (Berkeley) 6/4/93 37 * $FreeBSD: src/lib/libc/stdio/flags.c,v 1.6.2.1 2001/03/05 10:51:22 obrien Exp $ 38 * $DragonFly: src/lib/libc/stdio/flags.c,v 1.5 2005/01/31 22:29:40 dillon Exp $ 39 */ 40 41 #include <sys/types.h> 42 #include <sys/file.h> 43 #include <stdio.h> 44 #include <errno.h> 45 46 #include "local.h" 47 48 /* 49 * Return the (stdio) flags for a given mode. Store the flags 50 * to be passed to an _open() syscall through *optr. 51 * Return 0 on error. 52 */ 53 int 54 __sflags(const char *mode, int *optr) 55 { 56 int ret, m, o; 57 58 switch (*mode++) { 59 60 case 'r': /* open for reading */ 61 ret = __SRD; 62 m = O_RDONLY; 63 o = 0; 64 break; 65 66 case 'w': /* open for writing */ 67 ret = __SWR; 68 m = O_WRONLY; 69 o = O_CREAT | O_TRUNC; 70 break; 71 72 case 'a': /* open for appending */ 73 ret = __SWR; 74 m = O_WRONLY; 75 o = O_CREAT | O_APPEND; 76 break; 77 78 default: /* illegal mode */ 79 errno = EINVAL; 80 return (0); 81 } 82 83 /* [rwa]\+ or [rwa]b\+ means read and write */ 84 if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) { 85 ret = __SRW; 86 m = O_RDWR; 87 } 88 *optr = m | o; 89 return (ret); 90 } 91