1 /* $NetBSD: flags.c,v 1.7 1997/07/13 20:14:59 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. 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 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)flags.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: flags.c,v 1.7 1997/07/13 20:14:59 christos Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <sys/types.h> 49 #include <sys/file.h> 50 #include <stdio.h> 51 #include <errno.h> 52 #include "local.h" 53 54 /* 55 * Return the (stdio) flags for a given mode. Store the flags 56 * to be passed to an open() syscall through *optr. 57 * Return 0 on error. 58 */ 59 int 60 __sflags(mode, optr) 61 register const char *mode; 62 int *optr; 63 { 64 register int ret, m, o; 65 66 switch (*mode++) { 67 68 case 'r': /* open for reading */ 69 ret = __SRD; 70 m = O_RDONLY; 71 o = 0; 72 break; 73 74 case 'w': /* open for writing */ 75 ret = __SWR; 76 m = O_WRONLY; 77 o = O_CREAT | O_TRUNC; 78 break; 79 80 case 'a': /* open for appending */ 81 ret = __SWR; 82 m = O_WRONLY; 83 o = O_CREAT | O_APPEND; 84 break; 85 86 default: /* illegal mode */ 87 errno = EINVAL; 88 return (0); 89 } 90 91 /* [rwa]\+ or [rwa]b\+ means read and write */ 92 if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) { 93 ret = __SRW; 94 m = O_RDWR; 95 } 96 *optr = m | o; 97 return (ret); 98 } 99