int __cdecl _dup2 (
int fh1,
int fh2
)
{
int retcode;
/* validate file handles */
_CHECK_FH_CLEAR_OSSERR_RETURN( fh1, EBADF, -1 );
_VALIDATE_CLEAR_OSSERR_RETURN((fh1 >= 0 && (unsigned)fh1 < (unsigned)_nhandle), EBADF, -1);
_VALIDATE_CLEAR_OSSERR_RETURN((_osfile(fh1) & FOPEN), EBADF, -1);
_CHECK_FH_CLEAR_OSSERR_RETURN( fh2, EBADF, -1 );
_VALIDATE_CLEAR_OSSERR_RETURN(((unsigned)fh2 < _NHANDLE_), EBADF, -1);
/*
* Make sure there is an ioinfo struct corresponding to fh2.
*/
if ( (fh2 >= _nhandle) && (extend_ioinfo_arrays(fh2) != 0) ) {
errno = ENOMEM;
return -1;
}
/* get the two file handle locks; in order to prevent deadlock,
get the lowest handle lock first. */
if ( fh1 < fh2 ) {
_lock_fh(fh1);
_lock_fh(fh2);
}
else if ( fh1 > fh2 ) {
_lock_fh(fh2);
_lock_fh(fh1);
}
__try {
retcode = _dup2_nolock(fh1, fh2);
}
__finally {
_unlock_fh(fh1);
_unlock_fh(fh2);
}
return retcode;
}
int __cdecl _dup2 (
int fh1,
int fh2
)
{
ULONG dosretval; /* o.s. return code */
/* validate file handles */
if ( ((unsigned)fh1 >= (unsigned)_nhandle) ||
!(_osfile(fh1) & FOPEN) ||
((unsigned)fh2 >= _NHANDLE_) ) {
/* handle out of range */
errno = EBADF;
_doserrno = 0; /* not an OS error */
return -1;
}
/*
* Make sure there is an ioinfo struct corresponding to fh2.
*/
if ( (fh2 >= _nhandle) && (extend_ioinfo_arrays(fh2) != 0) ) {
errno = ENOMEM;
return -1;
}
#if defined(_MT) && !defined(DLL_FOR_WIN32S)
/* get the two file handle locks; in order to prevent deadlock,
get the lowest handle lock first. */
if ( fh1 < fh2 ) {
_lock_fh(fh1);
_lock_fh(fh2);
}
else if ( fh1 > fh2 ) {
_lock_fh(fh2);
_lock_fh(fh1);
}
/*
* Re-test and take care of case of unopened source handle. This is
* necessary only in the multi-thread case where the file have been
* closed by another thread before the lock was asserted, but after
* the initial test above.
*/
if ( !(_osfile(fh1) & FOPEN) ) {
/*
* Source handle isn't open, release locks and bail out with
* an error. Note that the DuplicateHandle API will not
* detect this error since it implies that _osfhnd(fh1) ==
* INVALID_HANDLE_VALUE, and this is a legal HANDLE value
* (it's the HANDLE for the current process).
*/
_unlock_fh(fh1);
_unlock_fh(fh2);
errno = EBADF;
_doserrno = 0; /* not an OS error */
return -1;
}
#endif
/*
* Take of the case of equal handles.
*/
if ( fh1 == fh2 ) {
/*
* Since fh1 is known to be open, return 0 indicating success.
* This is in conformance with the POSIX specification for
* dup2.
*/
_unlock_fh(fh1);
_unlock_fh(fh2);
return 0;
}
/*
* if fh2 is open, close it.
*/
if ( _osfile(fh2) & FOPEN )
/*
* close the handle. ignore the possibility of an error - an
* error simply means that an OS handle value may remain bound
* for the duration of the process. Use _close_lk as we
* already own lock
*/
(void) _close_lk(fh2);
/* Duplicate source file onto target file */
{
long new_osfhandle;
if ( !(DuplicateHandle(GetCurrentProcess(),
(HANDLE)_get_osfhandle(fh1),
GetCurrentProcess(),
(PHANDLE)&new_osfhandle,
0L,
TRUE,
DUPLICATE_SAME_ACCESS)
) ) {
dosretval = GetLastError();
} else {
_set_osfhnd(fh2, new_osfhandle);
dosretval = 0;
}
}
if (dosretval) {
_dosmaperr(dosretval);
_unlock_fh(fh1);
_unlock_fh(fh2);
return -1;
}
/* copy _osfile information */
_osfile(fh2) = _osfile(fh1);
/* unlock file handles */
_unlock_fh(fh1);
_unlock_fh(fh2);
return 0;
}
