text: /*-
   * Copyright (c) 1990, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * Chris Torek.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #if defined(LIBC_SCCS) && !defined(lint)
  static char sccsid[] = "@(#)flags.c	8.1 (Berkeley) 6/4/93";
  #endif /* LIBC_SCCS and not lint */
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD: src/lib/libc/stdio/flags.c,v 1.9 2002/03/22 21:53:04 obrien Exp $");
  
  #include <sys/types.h>
  #include <sys/file.h>
  #include <stdio.h>
  #include <errno.h>
  
  #include "local.h"
  
  /*
   * Return the (stdio) flags for a given mode.  Store the flags
   * to be passed to an _open() syscall through *optr.
   * Return 0 on error.
   */
  int
  __sflags(mode, optr)
  	const char *mode;
  	int *optr;
  {
  	int ret, m, o;
  
  	switch (*mode++) {
  
  	case 'r':	/* open for reading */
  		ret = __SRD;
  		m = O_RDONLY;
  		o = 0;
  		break;
  
  	case 'w':	/* open for writing */
  		ret = __SWR;
  		m = O_WRONLY;
  		o = O_CREAT | O_TRUNC;
  		break;
  
  	case 'a':	/* open for appending */
  		ret = __SWR;
  		m = O_WRONLY;
  		o = O_CREAT | O_APPEND;
  		break;
  
  	default:	/* illegal mode */
  		errno = EINVAL;
  		return (0);
  	}
  
  	/* [rwa]\+ or [rwa]b\+ means read and write */
  	if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) {
  		ret = __SRW;
  		m = O_RDWR;
  	}
  	*optr = m | o;
  	return (ret);
  }
  