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 * @(#)flags.c 8.1 (Berkeley) 6/4/93 33 * $FreeBSD: src/lib/libc/stdio/flags.c,v 1.10 2007/01/09 00:28:06 imp Exp $ 34 * $DragonFly: src/lib/libc/stdio/flags.c,v 1.5 2005/01/31 22:29:40 dillon Exp $ 35 */ 36 37 #include <sys/types.h> 38 #include <sys/file.h> 39 #include <stdio.h> 40 #include <errno.h> 41 42 #include "local.h" 43 44 /* 45 * Return the (stdio) flags for a given mode. Store the flags 46 * to be passed to an _open() syscall through *optr. 47 * Return 0 on error. 48 */ 49 int 50 __sflags(const char *mode, int *optr) 51 { 52 int ret, m, o; 53 54 switch (*mode++) { 55 56 case 'r': /* open for reading */ 57 ret = __SRD; 58 m = O_RDONLY; 59 o = 0; 60 break; 61 62 case 'w': /* open for writing */ 63 ret = __SWR; 64 m = O_WRONLY; 65 o = O_CREAT | O_TRUNC; 66 break; 67 68 case 'a': /* open for appending */ 69 ret = __SWR; 70 m = O_WRONLY; 71 o = O_CREAT | O_APPEND; 72 break; 73 74 default: /* illegal mode */ 75 errno = EINVAL; 76 return (0); 77 } 78 79 /* [rwa]\+ or [rwa]b\+ means read and write */ 80 if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) { 81 ret = __SRW; 82 m = O_RDWR; 83 } 84 *optr = m | o; 85 return (ret); 86 } 87