newlib/newlib/libc/stdio/flags.c

95 lines
2.1 KiB
C

/*
* 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 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/* No user fns here. Pesch 15apr92 */
#include <_ansi.h>
#include <stdio.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/types.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 (struct _reent *ptr,
register char *mode,
int *optr)
{
register int ret, m, o;
switch (mode[0])
{
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 | __SAPP;
m = O_WRONLY;
o = O_CREAT | O_APPEND;
break;
default: /* illegal mode */
ptr->_errno = EINVAL;
return (0);
}
while (*++mode)
{
switch (*mode)
{
case '+':
ret = (ret & ~(__SRD | __SWR)) | __SRW;
m = (m & ~O_ACCMODE) | O_RDWR;
break;
case 'b':
#ifdef O_BINARY
m |= O_BINARY;
#endif
break;
#ifdef __CYGWIN__
case 't':
m |= O_TEXT;
break;
#endif
#if defined (O_CLOEXEC) && defined (_GLIBC_EXTENSION)
case 'e':
m |= O_CLOEXEC;
break;
#endif
case 'x':
m |= O_EXCL;
break;
default:
break;
}
}
*optr = m | o;
return ret;
}