1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 #if defined(LIBC_SCCS) && !defined(lint) 36 static char sccsid[] = "@(#)flags.c 8.1 (Berkeley) 6/4/93"; 37 #endif /* LIBC_SCCS and not lint */ 38 #include <sys/types.h> 39 #include <sys/file.h> 40 #include <stdio.h> 41 #include <errno.h> 42 43 #include "local.h" 44 45 /* 46 * Return the (stdio) flags for a given mode. Store the flags 47 * to be passed to an _open() syscall through *optr. 48 * Return 0 on error. 49 */ 50 int 51 __sflags(const char *mode, int *optr) 52 { 53 int ret, m, o, known; 54 55 switch (*mode++) { 56 57 case 'r': /* open for reading */ 58 ret = __SRD; 59 m = O_RDONLY; 60 o = 0; 61 break; 62 63 case 'w': /* open for writing */ 64 ret = __SWR; 65 m = O_WRONLY; 66 o = O_CREAT | O_TRUNC; 67 break; 68 69 case 'a': /* open for appending */ 70 ret = __SWR; 71 m = O_WRONLY; 72 o = O_CREAT | O_APPEND; 73 break; 74 75 default: /* illegal mode */ 76 errno = EINVAL; 77 return (0); 78 } 79 80 do { 81 known = 1; 82 switch (*mode++) { 83 case 'b': 84 /* 'b' (binary) is ignored */ 85 break; 86 case '+': 87 /* [rwa][b]\+ means read and write */ 88 ret = __SRW; 89 m = O_RDWR; 90 break; 91 case 'x': 92 /* 'x' means exclusive (fail if the file exists) */ 93 o |= O_EXCL; 94 break; 95 case 'e': 96 /* set close-on-exec */ 97 o |= O_CLOEXEC; 98 break; 99 case 'v': 100 /* verify */ 101 o |= O_VERIFY; 102 break; 103 default: 104 known = 0; 105 break; 106 } 107 } while (known); 108 109 if ((o & O_EXCL) != 0 && m == O_RDONLY) { 110 errno = EINVAL; 111 return (0); 112 } 113 114 *optr = m | o; 115 return (ret); 116 } 117