/*
 * Copyright (c) 1990 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * and/or other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
/* No user fns here. Pesch 15apr92 */

#include "stdio_private.h"

/*
 * Return the (stdio) flags for a given mode. Store the flags to be
 * passed to open() through *optr.
 *
 * Return 0 on error.
 */

int
__stdio_flags(const char *mode, int *optr)
{
    int ret;
    int o;

    switch (mode[0]) {
    case 'r': /* open for reading */
        ret = __SRD;
        o = O_RDONLY;
        break;

    case 'w': /* open for writing */
        ret = __SWR;
        o = O_WRONLY | O_CREAT | O_TRUNC;
        break;

    case 'a': /* open for appending */
        ret = __SWR;
        o = O_WRONLY | O_CREAT | O_APPEND;
        break;

    default: /* illegal mode */
        errno = EINVAL;
        return (0);
    }
    while (*++mode) {
        switch (*mode) {
        case '+':
            ret |= (__SRD | __SWR);
            o = (o & ~O_ACCMODE) | O_RDWR;
            break;
        default:
            break;
        }
    }
    *optr = o;
    return ret;
}
