1 /* $NetBSD: flags.c,v 1.5 1995/02/02 02:09:19 jtc 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #if defined(LIBC_SCCS) && !defined(lint) 40 #if 0 41 static char sccsid[] = "@(#)flags.c 8.1 (Berkeley) 6/4/93"; 42 #endif 43 static char rcsid[] = "$NetBSD: flags.c,v 1.5 1995/02/02 02:09:19 jtc Exp $"; 44 #endif /* LIBC_SCCS and not lint */ 45 46 #include <sys/types.h> 47 #include <sys/file.h> 48 #include <stdio.h> 49 #include <errno.h> 50 51 /* 52 * Return the (stdio) flags for a given mode. Store the flags 53 * to be passed to an open() syscall through *optr. 54 * Return 0 on error. 55 */ 56 int 57 __sflags(mode, optr) 58 register char *mode; 59 int *optr; 60 { 61 register int ret, m, o; 62 63 switch (*mode++) { 64 65 case 'r': /* open for reading */ 66 ret = __SRD; 67 m = O_RDONLY; 68 o = 0; 69 break; 70 71 case 'w': /* open for writing */ 72 ret = __SWR; 73 m = O_WRONLY; 74 o = O_CREAT | O_TRUNC; 75 break; 76 77 case 'a': /* open for appending */ 78 ret = __SWR; 79 m = O_WRONLY; 80 o = O_CREAT | O_APPEND; 81 break; 82 83 default: /* illegal mode */ 84 errno = EINVAL; 85 return (0); 86 } 87 88 /* [rwa]\+ or [rwa]b\+ means read and write */ 89 if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) { 90 ret = __SRW; 91 m = O_RDWR; 92 } 93 *optr = m | o; 94 return (ret); 95 } 96