newlib-cygwin/newlib/libc/stdio/fdopen.c

132 lines
3.2 KiB
C

/*
* Copyright (c) 1990 The 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.
*/
/*
FUNCTION
<<fdopen>>---turn open file into a stream
INDEX
fdopen
INDEX
_fdopen_r
SYNOPSIS
#include <stdio.h>
FILE *fdopen(int <[fd]>, const char *<[mode]>);
FILE *_fdopen_r(struct _reent *<[reent]>,
int <[fd]>, const char *<[mode]>);
DESCRIPTION
<<fdopen>> produces a file descriptor of type <<FILE *>>, from a
descriptor for an already-open file (returned, for example, by the
system subroutine <<open>> rather than by <<fopen>>).
The <[mode]> argument has the same meanings as in <<fopen>>.
RETURNS
File pointer or <<NULL>>, as for <<fopen>>.
PORTABILITY
<<fdopen>> is ANSI.
*/
#include <_ansi.h>
#include <reent.h>
#include <sys/types.h>
#include <sys/fcntl.h>
#include <stdio.h>
#include <errno.h>
#include "local.h"
#include <_syslist.h>
FILE *
_fdopen_r (struct _reent *ptr,
int fd,
const char *mode)
{
register FILE *fp;
int flags, oflags;
#ifdef HAVE_FCNTL
int fdflags, fdmode;
#endif
if ((flags = __sflags (ptr, mode, &oflags)) == 0)
return 0;
/* make sure the mode the user wants is a subset of the actual mode */
#ifdef HAVE_FCNTL
if ((fdflags = _fcntl_r (ptr, fd, F_GETFL, 0)) < 0)
return 0;
fdmode = fdflags & O_ACCMODE;
if (fdmode != O_RDWR && (fdmode != (oflags & O_ACCMODE)))
{
_REENT_ERRNO(ptr) = EBADF;
return 0;
}
#endif
if ((fp = __sfp (ptr)) == 0)
return 0;
_newlib_flockfile_start (fp);
fp->_flags = flags;
/* POSIX recommends setting the O_APPEND bit on fd to match append
streams. Someone may later clear O_APPEND on fileno(fp), but the
stream must still remain in append mode. Rely on __sflags
setting __SAPP properly. */
#ifdef HAVE_FCNTL
if ((oflags & O_APPEND) && !(fdflags & O_APPEND))
_fcntl_r (ptr, fd, F_SETFL, fdflags | O_APPEND);
#endif
fp->_file = fd;
fp->_cookie = (void *) fp;
#undef _read
#undef _write
#undef _seek
#undef _close
fp->_read = __sread;
fp->_write = __swrite;
fp->_seek = __sseek;
fp->_close = __sclose;
#ifdef __SCLE
/* Explicit given mode results in explicit setting mode on fd */
if (oflags & O_BINARY)
setmode (fp->_file, O_BINARY);
else if (oflags & O_TEXT)
setmode (fp->_file, O_TEXT);
if (__stextmode (fp->_file))
fp->_flags |= __SCLE;
#endif
_newlib_flockfile_end (fp);
return fp;
}
#ifndef _REENT_ONLY
FILE *
fdopen (int fd,
const char *mode)
{
return _fdopen_r (_REENT, fd, mode);
}
#endif