1 /* $NetBSD: flags.c,v 1.17 2012/11/15 03:50:36 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)flags.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 __RCSID("$NetBSD: flags.c,v 1.17 2012/11/15 03:50:36 christos Exp $"); 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/types.h> 45 #include <assert.h> 46 #include <fcntl.h> 47 #include <stdio.h> 48 #include <errno.h> 49 #include "reentrant.h" 50 #include "local.h" 51 52 /* 53 * Return the (stdio) flags for a given mode. Store the flags 54 * to be passed to an open() syscall through *optr. 55 * Return 0 on error. 56 */ 57 int 58 __sflags(const char *mode, int *optr) 59 { 60 int ret, m, o; 61 62 _DIAGASSERT(mode != NULL); 63 64 switch (*mode++) { 65 66 case 'r': /* open for reading */ 67 ret = __SRD; 68 m = O_RDONLY; 69 o = 0; 70 break; 71 72 case 'w': /* open for writing */ 73 ret = __SWR; 74 m = O_WRONLY; 75 o = O_CREAT | O_TRUNC; 76 break; 77 78 case 'a': /* open for appending */ 79 ret = __SWR; 80 m = O_WRONLY; 81 o = O_CREAT | O_APPEND; 82 break; 83 84 default: /* illegal mode */ 85 errno = EINVAL; 86 return 0; 87 } 88 89 /* 90 * [rwa]\+ or [rwa]b\+ means read and write 91 * f means open only plain files, 92 * e means set close on exec. 93 * x means exclusive open. 94 */ 95 for (; *mode; mode++) 96 switch (*mode) { 97 case '+': 98 ret = __SRW; 99 m = O_RDWR; 100 break; 101 case 'f': 102 o |= O_NONBLOCK; 103 break; 104 case 'e': 105 o |= O_CLOEXEC; 106 break; 107 case 'x': 108 o |= O_EXCL; 109 break; 110 case 'b': 111 break; 112 default: /* We could produce a warning here */ 113 break; 114 } 115 116 *optr = m | o; 117 return ret; 118 } 119