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

128 lines
2.5 KiB
C

/*
FUNCTION
<<fdopen>>---turn open file into a stream
INDEX
fdopen
INDEX
_fdopen_r
ANSI_SYNOPSIS
#include <stdio.h>
FILE *fdopen(int <[fd]>, const char *<[mode]>);
FILE *_fdopen_r(void *<[reent]>,
int <[fd]>, const char *<[mode]>);
TRAD_SYNOPSIS
#include <stdio.h>
FILE *fdopen(<[fd]>, <[mode]>)
int <[fd]>;
char *<[mode]>;
FILE *_fdopen_r(<[reent]>, <[fd]>, <[mode]>)
char *<[reent]>;
int <[fd]>;
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 <sys/types.h>
#include <sys/fcntl.h>
#include <stdio.h>
#include <errno.h>
#include "local.h"
#include <_syslist.h>
extern int __sflags ();
FILE *
_DEFUN (_fdopen_r, (ptr, fd, mode),
struct _reent *ptr _AND
int fd _AND
_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)))
{
ptr->_errno = EBADF;
return 0;
}
#endif
if ((fp = __sfp (ptr)) == 0)
return 0;
fp->_flags = flags;
/*
* If opened for appending, but underlying descriptor
* does not have O_APPEND bit set, assert __SAPP so that
* __swrite() will lseek to end before each write.
*/
if ((oflags & O_APPEND)
#ifdef HAVE_FCNTL
&& !(fdflags & O_APPEND)
#endif
)
fp->_flags |= __SAPP;
fp->_file = fd;
fp->_cookie = (_PTR) 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
return fp;
}
#ifndef _REENT_ONLY
FILE *
_DEFUN (fdopen, (fd, mode),
int fd _AND
_CONST char *mode)
{
return _fdopen_r (_REENT, fd, mode);
}
#endif