int __cdecl _eof (
int filedes
)
{
long here;
long end;
int retval;
if ( ((unsigned)filedes >= (unsigned)_nhandle) ||
!(_osfile(filedes) & FOPEN) )
{
errno = EBADF;
_doserrno = 0;
return(-1);
}
/* Lock the file */
_lock_fh(filedes);
/* See if the current position equals the end of the file. */
if ( ((here = _lseek_lk(filedes, 0L, SEEK_CUR)) == -1L) ||
((end = _lseek_lk(filedes, 0L, SEEK_END)) == -1L) )
retval = -1;
else if ( here == end )
retval = 1;
else {
_lseek_lk(filedes, here, SEEK_SET);
retval = 0;
}
/* Unlock the file */
_unlock_fh(filedes);
/* Done */
return(retval);
}
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;
}
FILE * __cdecl _tpopen (
const _TSCHAR *cmdstring,
const _TSCHAR *type
)
{
int phdls[2]; /* I/O handles for pipe */
int ph_open[2]; /* flags, set if correspond phdls is open */
int i1; /* index into phdls[] */
int i2; /* index into phdls[] */
int tm = 0; /* flag indicating text or binary mode */
int stdhdl; /* either STDIN or STDOUT */
HANDLE osfhndsv1; /* used to save _osfhnd(stdhdl) */
long osfhndsv2; /* used to save _osfhnd(phdls[i2]) */
char osfilesv1; /* used to save _osfile(stdhdl) */
char osfilesv2; /* used to save _osfile(phdls[i2]) */
HANDLE oldhnd; /* used to hold OS file handle values... */
HANDLE newhnd; /* ...in calls to DuplicateHandle API */
FILE *pstream; /* stream to be associated with pipe */
HANDLE prochnd; /* handle for current process */
_TSCHAR *cmdexe; /* pathname for the command processor */
int childhnd; /* handle for child process (cmd.exe) */
IDpair *locidpair; /* pointer to IDpair table entry */
/* first check for errors in the arguments
*/
if ( (cmdstring == NULL) || (type == NULL) || ((*type != 'w') &&
(*type != _T('r'))) )
goto error1;
/* do the _pipe(). note that neither of the resulting handles will
* be inheritable.
*/
if ( *(type + 1) == _T('t') )
tm = _O_TEXT;
else if ( *(type + 1) == _T('b') )
tm = _O_BINARY;
tm |= _O_NOINHERIT;
if ( _pipe( phdls, PSIZE, tm ) == -1 )
goto error1;
/* test *type and set stdhdl, i1 and i2 accordingly.
*/
if ( *type == _T('w') ) {
stdhdl = STDIN;
i1 = 0;
i2 = 1;
}
else {
stdhdl = STDOUT;
i1 = 1;
i2 = 0;
}
/* the pipe now exists. the following steps must be carried out before
* the child process (cmd.exe) may be spawned:
*
* 1. save a non-inheritable dup of stdhdl
*
* 2. force stdhdl to be a dup of ph[i1]. close both ph[i1] and
* the original OS handle underlying stdhdl
*
* 3. associate a stdio-level stream with ph[i2].
*/
/* set flags to indicate pipe handles are open. note, these are only
* used for error recovery.
*/
ph_open[ 0 ] = ph_open[ 1 ] = 1;
/* get the process handle, it will be needed in some API calls
*/
prochnd = GetCurrentProcess();
/* MULTI-THREAD: ASSERT LOCK ON STDHDL HERE!!!!
*/
_lock_fh( stdhdl );
/* save a non-inheritable copy of stdhdl for later restoration.
*/
oldhnd = (HANDLE)_osfhnd( stdhdl );
if ( (oldhnd == INVALID_HANDLE_VALUE) ||
!DuplicateHandle( prochnd,
oldhnd,
prochnd,
&osfhndsv1,
0L,
FALSE, /* non-inheritable */
DUPLICATE_SAME_ACCESS )
) {
goto error2;
}
osfilesv1 = _osfile( stdhdl );
/* force stdhdl to an inheritable dup of phdls[i1] (i.e., force
* STDIN to the pipe read handle or STDOUT to the pipe write handle)
* and close phdls[i1] (so there won't be a stray open handle on the
* pipe after a _pclose). also, clear ph_open[i1] flag so that error
* recovery won't try to close it again.
*/
if ( !DuplicateHandle( prochnd,
(HANDLE)_osfhnd( phdls[i1] ),
prochnd,
&newhnd,
0L,
TRUE, /* inheritable */
DUPLICATE_SAME_ACCESS )
) {
goto error3;
}
(void)CloseHandle( (HANDLE)_osfhnd(stdhdl) );
_free_osfhnd( stdhdl );
_set_osfhnd( stdhdl, (long)newhnd );
_osfile( stdhdl ) = _osfile( phdls[i1] );
(void)_close( phdls[i1] );
ph_open[ i1 ] = 0;
/* associate a stream with phdls[i2]. note that if there are no
* errors, pstream is the return value to the caller.
*/
if ( (pstream = _tfdopen( phdls[i2], type )) == NULL )
goto error4;
/* MULTI-THREAD: ASSERT LOCK ON IDPAIRS HERE!!!!
*/
_mlock( _POPEN_LOCK );
/* next, set locidpair to a free entry in the idpairs table.
*/
if ( (locidpair = idtab( NULL )) == NULL )
goto error5;
/* temporarily change the osfhnd and osfile entries so that
* the child doesn't get any entries for phdls[i2].
*/
osfhndsv2 = _osfhnd( phdls[i2] );
_osfhnd( phdls[i2] ) = (long)INVALID_HANDLE_VALUE;
osfilesv2 = _osfile( phdls[i2] );
_osfile( phdls[i2] ) = 0;
/* spawn the child copy of cmd.exe. the algorithm is adapted from
* SYSTEM.C, and behaves the same way.
*/
if ( ((cmdexe = _tgetenv(_T("COMSPEC"))) == NULL) ||
(((childhnd = _tspawnl( _P_NOWAIT,
cmdexe,
cmdexe,
_T("/c"),
cmdstring,
NULL ))
== -1) && ((errno == ENOENT) || (errno == EACCES))) ) {
/*
* either COMSPEC wasn't defined, or the spawn failed because
* cmdexe wasn't found or was inaccessible. in either case, try to
* spawn "cmd.exe" (Windows NT) or "command.com" (Windows 95) instead
* Note that spawnlp is used here so that the path is searched.
*/
cmdexe = ( _osver & 0x8000 ) ? _T("command.com") : _T("cmd.exe");
childhnd = _tspawnlp( _P_NOWAIT,
cmdexe,
cmdexe,
_T("/c"),
cmdstring,
NULL);
}
_osfhnd( phdls[i2] ) = osfhndsv2;
_osfile( phdls[i2] ) = osfilesv2;
/* check if the last (perhaps only) spawn attempt was successful
*/
if ( childhnd == -1 )
goto error6;
/* restore stdhdl for the current process, set value of *locidpair,
* close osfhndsv1 (note that CloseHandle must be used instead of close)
* and return pstream to the caller
*/
(void)DuplicateHandle( prochnd,
osfhndsv1,
prochnd,
&newhnd,
0L,
TRUE, /* inheritable */
DUPLICATE_CLOSE_SOURCE | /* close osfhndsv1 */
DUPLICATE_SAME_ACCESS );
(void)CloseHandle( (HANDLE)_osfhnd(stdhdl) );
_free_osfhnd( stdhdl );
_set_osfhnd( stdhdl, (long)newhnd );
_osfile(stdhdl) = osfilesv1;
/* MULTI-THREAD: RELEASE LOCK ON STDHDL HERE!!!!
*/
_unlock_fh( stdhdl );
locidpair->prochnd = childhnd;
locidpair->stream = pstream;
/* MULTI-THREAD: RELEASE LOCK ON IDPAIRS HERE!!!!
*/
_munlock( _POPEN_LOCK );
/* all successful calls to _popen return to the caller via this return
* statement!
*/
return( pstream );
/**
* error handling code. all detected errors end up here, entering
* via a goto one of the labels. note that the logic is currently
* a straight fall-thru scheme (e.g., if entered at error5, the
* code for error5, error4,...,error1 is all executed).
**********************************************************************/
error6: /* make sure locidpair is reusable
*/
locidpair->stream = NULL;
error5: /* close pstream (also, clear ph_open[i2] since the stream
* close will also close the pipe handle)
*/
(void)fclose( pstream );
ph_open[ i2 ] = 0;
/* MULTI-THREAD: RELEASE LOCK ON IDPAIRS HERE!!!!
*/
_munlock(_POPEN_LOCK);
error4: /* restore stdhdl
*/
(void)DuplicateHandle( prochnd,
osfhndsv1,
prochnd,
&newhnd,
0L,
TRUE,
DUPLICATE_SAME_ACCESS );
(void)CloseHandle( (HANDLE)_osfhnd(stdhdl) );
_free_osfhnd( stdhdl );
_set_osfhnd( stdhdl, (long)newhnd );
_osfile( stdhdl ) = osfilesv1;
/* MULTI-THREAD: RELEASE LOCK ON STDHDL HERE!!!!
*/
_unlock_fh( stdhdl );
error3: /* close osfhndsv1
*/
CloseHandle( osfhndsv1 );
error2: /* close handles on pipe (if they are still open)
*/
if ( ph_open[i1] )
_close( phdls[i1] );
if ( ph_open[i2] )
_close( phdls[i2] );
error1: /* return NULL to the caller indicating failure
*/
return( NULL );
}
int __cdecl _dup (
int fh
)
{
ULONG dosretval; /* o.s. return value */
int newfh; /* variable for new file handle */
char fileinfo; /* _osfile info for file */
long new_osfhandle;
/* validate file handle */
if ( ((unsigned)fh >= (unsigned)_nhandle) ||
!(_osfile(fh) & FOPEN) )
{
errno = EBADF;
_doserrno = 0; /* no o.s. error */
return -1;
}
_lock_fh(fh); /* lock file handle */
fileinfo = _osfile(fh); /* get file info for file */
/* create duplicate handle */
if ( (newfh = _alloc_osfhnd()) == -1 )
{
errno = EMFILE; /* too many files error */
_doserrno = 0L; /* not an OS error */
_unlock_fh(fh);
return -1; /* return error to caller */
}
/*
* duplicate the file handle
*/
if ( !(DuplicateHandle(GetCurrentProcess(),
(HANDLE)_get_osfhandle(fh),
GetCurrentProcess(),
(PHANDLE)&new_osfhandle,
0L,
TRUE,
DUPLICATE_SAME_ACCESS)) )
{
dosretval = GetLastError();
}
else {
_set_osfhnd(newfh, new_osfhandle);
dosretval = 0;
}
_unlock_fh(newfh);
_unlock_fh(fh); /* unlock file handle */
if (dosretval) {
/* o.s. error -- map and return */
_dosmaperr(dosretval);
return -1;
}
/*
* copy the _osfile value, with the FNOINHERIT bit cleared
*/
_osfile(newfh) = fileinfo & ~FNOINHERIT;
return newfh;
}
