1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 /*static char *sccsid = "from: @(#)flags.c 5.1 (Berkeley) 1/20/91";*/ 39 static char *rcsid = "$Id: flags.c,v 1.4 1993/12/31 19:14:15 jtc Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 #include <sys/file.h> 44 #include <stdio.h> 45 #include <errno.h> 46 47 /* 48 * Return the (stdio) flags for a given mode. Store the flags 49 * to be passed to an open() syscall through *optr. 50 * Return 0 on error. 51 */ 52 int 53 __sflags(mode, optr) 54 register char *mode; 55 int *optr; 56 { 57 register int ret, m, o; 58 59 switch (*mode++) { 60 61 case 'r': /* open for reading */ 62 ret = __SRD; 63 m = O_RDONLY; 64 o = 0; 65 break; 66 67 case 'w': /* open for writing */ 68 ret = __SWR; 69 m = O_WRONLY; 70 o = O_CREAT | O_TRUNC; 71 break; 72 73 case 'a': /* open for appending */ 74 ret = __SWR; 75 m = O_WRONLY; 76 o = O_CREAT | O_APPEND; 77 break; 78 79 default: /* illegal mode */ 80 errno = EINVAL; 81 return (0); 82 } 83 84 /* [rwa]\+ or [rwa]b\+ means read and write */ 85 if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) { 86 ret = __SRW; 87 m = O_RDWR; 88 } 89 *optr = m | o; 90 return (ret); 91 } 92