dan@hrc.UUCP (Dan Troxel VP) (12/14/88)
Is there another dev/* that I can use to open the terminal io using rn? The error I receive is as follows: Can't open /dev/tty No such device or address Specifics: Convergent Tech S/640 running the CTAM 2.00 windowing software Rn will work fine from a standard shell, but under the windowing application, it gives me that above error. -- Dan Troxel VP of Computer Operations @ Handwriting Research Corporation - 2821 E. Camelback Road Suite 600 Phoenix, AZ 85016 WK 1-602-957-8870 HM 1-602-435-1240 UUCP : asuvax!hrc!dan
jiii@visdc.UUCP (John E Van Deusen III) (12/17/88)
I once had a similar problem opening /dev/tty with a program that was running in a pipe line but needed to fork an interactive shell every so often. In order to have access to the terminal, I invoked the shell command exec </dev/tty >/dev/tty. If I then attempted to su(1) to another uid, the standard input would not be readable. The reason was that the permissions and ownerships from the previous uid had somehow remained in effect. The curious thing was that this would only happen if the input and output had previously been redirected to pipes. As I recall, exec 0<&2 1>&2 solved the problem, so I would suggest that you dup(2) the standard error file file descriptor. This has the added advantage that /etc/ttytype remains useful.
bdb@becker.UUCP (Bruce Becker) (12/17/88)
In article <373@hrc.UUCP> dan@hrc.UUCP (Dan Troxel VP) writes: > >Is there another dev/* that I can use to open the terminal io using rn? >The error I receive is as follows: > Can't open /dev/tty > No such device or address >Specifics: > Convergent Tech S/640 running the CTAM 2.00 windowing software There is a similar problem in the windowing software for the AT&T 3B1 version of CTIX. In that system the problem occurs when "/dev/tty" is the internal modem; certain open flags determine the state of the opened device (whether data or voice use of the phone line in that case). Look in the terminal i/o section of the 'rn' source - I don't have it online at the moment, but I seem to recall "term" or something as the routine in question, in which "/dev/tty" is opened to a new file descriptor. Check to see that 'O_RDONLY' mode doesn't have some special meaning for window systems which would be averted using 'O_RDWR' or similar. Perhaps this isn't the problem, but if it is, it takes some detective work (not mine in the 3B1 case) to find out. Good luck, in any case - 'rn' is a valuble resource... >Rn will work fine from a standard shell, but under the windowing application, >it gives me that above error. >-- >Dan Troxel VP of Computer Operations @ >Handwriting Research Corporation - 2821 E. Camelback Road Suite 600 >Phoenix, AZ 85016 WK 1-602-957-8870 HM 1-602-435-1240 >UUCP : asuvax!hrc!dan Cheers, -- Bruce Becker Toronto, Ont. Internet: bdb@becker.UUCP, bruce@gpu.utcs.toronto.edu, becker@ziebmef.UUCP BitNet: BECKER@HUMBER.BITNET "Paranoia is its own reward" - Lyon Bullroarey, honorary American