chip@ateng.UUCP (Chip Salzenberg) (02/05/88)
A question for those of you with UNIX kernel source code:
If you call open() on a device file, and you then call close() on
the open file descriptor, but the driver for that device reports an
error on the close, is the file descriptor closed or not?
We are running SCO Xenix System V, but we're interested in the results
for all types of machines.
Please E-mail and I'll post a summary.
--
Chip Salzenberg UUCP: "{codas,uunet}!ateng!chip"
A T Engineering My employer's opinions are a trade secret.
"Anything that works is better than anything that doesn't."jh@pcsbst (02/12/88)
Freeing the file descriptor is the first job done by the UNIX SVR3 close() system call. Thus, you may reuse it. Whatever happens else is the responsibility of the kernel. Since I have seem some code in which u.u_error was tested in the kernel [ after some operations like bread() ] I would strictly advise against a driver close function to return an error code! If the error condition is severe I would recommend a console message from inside the kernel. Note, that the close() code is protected from signals. Johannes Heuft unido!pcsbst!jh