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 * 4. 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 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)flags.c 8.1 (Berkeley) 6/4/93"; 35 #endif /* LIBC_SCCS and not lint */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <sys/types.h> 40 #include <sys/file.h> 41 #include <stdio.h> 42 #include <errno.h> 43 44 #include "local.h" 45 46 /* 47 * Return the (stdio) flags for a given mode. Store the flags 48 * to be passed to an _open() syscall through *optr. 49 * Return 0 on error. 50 */ 51 int 52 __sflags(mode, optr) 53 const char *mode; 54 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 /* 'b' (binary) is ignored */ 84 if (*mode == 'b') 85 mode++; 86 87 /* [rwa][b]\+ means read and write */ 88 if (*mode == '+') { 89 mode++; 90 ret = __SRW; 91 m = O_RDWR; 92 } 93 94 /* 'b' (binary) can appear here, too -- and is ignored again */ 95 if (*mode == 'b') 96 mode++; 97 98 /* 'x' means exclusive (fail if the file exists) */ 99 if (*mode == 'x') { 100 if (m == O_RDONLY) { 101 errno = EINVAL; 102 return (0); 103 } 104 o |= O_EXCL; 105 } 106 107 *optr = m | o; 108 return (ret); 109 } 110