1 /* $NetBSD: flags.c,v 1.16 2012/03/15 18:22:30 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 1.16 2012/03/15 18:22:30 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 #if defined(__minix) && !defined(O_CLOEXEC) 53 #define O_CLOEXEC 0 54 #endif 55 56 /* 57 * Return the (stdio) flags for a given mode. Store the flags 58 * to be passed to an open() syscall through *optr. 59 * Return 0 on error. 60 */ 61 int 62 __sflags(const char *mode, int *optr) 63 { 64 int ret, m, o; 65 66 _DIAGASSERT(mode != NULL); 67 68 switch (*mode++) { 69 70 case 'r': /* open for reading */ 71 ret = __SRD; 72 m = O_RDONLY; 73 o = 0; 74 break; 75 76 case 'w': /* open for writing */ 77 ret = __SWR; 78 m = O_WRONLY; 79 o = O_CREAT | O_TRUNC; 80 break; 81 82 case 'a': /* open for appending */ 83 ret = __SWR; 84 m = O_WRONLY; 85 o = O_CREAT | O_APPEND; 86 break; 87 88 default: /* illegal mode */ 89 errno = EINVAL; 90 return 0; 91 } 92 93 /* 94 * [rwa]\+ or [rwa]b\+ means read and write 95 * f means open only plain files, 96 * e means set close on exec. 97 */ 98 for (; *mode; mode++) 99 switch (*mode) { 100 case '+': 101 ret = __SRW; 102 m = O_RDWR; 103 break; 104 case 'f': 105 o |= O_NONBLOCK; 106 break; 107 case 'e': 108 o |= O_CLOEXEC; 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