From:	CSBVAX::MRGATE!@KL.SRI.Com,@wiscvm.wisc.edu:twade@csvax.ucd.hea.irl@SMTP 25-JUN-1987 06:53
To:	EVERHART
Subj:	DTR SIGNALS, THANKS AND APOLOGIES.

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Date:     23-JUN-1987 09:57:59
From:      <TWADE@CSVAX.UCD.HEA.IRL>
To:       INFO-VAX@KL.SRI.COM
Subject:    DTR SIGNALS, THANKS AND APOLOGIES.
Sender:    Tom Wade <twade@csvax.ucd.hea.irl>

1.    Somebody wanted a program to drop DTR line on a terminal. The
    following program may be of use. It is part of an automatic logout
    feature which ensures the user is also disconnected from our
    Gandalf switch. The program is called as a foreign command with
    the terminal name as the argument.

File HANGUP.MAR
--------X Cut Here X----------------------------------------------------------
;    Hang up a modem line. Normally done after
;    bouncing a user if the terminal mode is set
;    to /NOHANGUP

        .Title    HANGUP

Device:        .Long    20            ; string descriptor
        .Address dev_text        ; for device to be
Dev_text:    .Blkb    20            ; hung up.
Ttchan:        .Word    0            ; channel to terminal
Iosb:        .Quad    0            ; status block

        .Entry    Start    M <R6>

        Pushaq    device            ; get device name from
        Calls    #1, GLIB$GET_FOREIGN    ; foreign comand utility
        Blbc    R0,    error        ; check for no command

        $ASSIGN_S -            ; open terminal
            chan = ttchan, -
            devnam = device
        Blbc    R0,    error

        $QIOW_S -            ; drop the DTR signal
            chan = ttchan, -
            func = #<IO$_SETMODE!IO$M_HANGUP>, -
            iosb = iosb
        Blbc    R0,    error

        Movzwl    iosb,    R0        ; now test the status
        Blbc    R0,    error        ; return value.

        $DASSGN_S -            ; close the channel
            chan = ttchan

        Ret                ; won't fail

Error:        Movl    R0,    R6        ; save failure code
        $DASSGN_S -            ; first close the channel
            chan = ttchan        ; (ignore error if already
                        ; closed).

        Movl    R6,    R0        ; restore failure code
        Ret                ; and hand it to DCL

        .End    Start
---------X Cut Here X-----------------------------------------------------------

2.    Many thanks to those who responded to my query on Gmail, it sounds
    a useful tool, and I will probably implement it here.

3.    Apologies to anyone I may have misled concerning my suggestion about
    raising priorities. In a previous message, I suggested using the
    $SETUAI service in a privileged program to change the max priority
    for a user. This, of course, will not work, as the SYSUAF is only
    consulted by LOGINOUT when the process is started. I can only offer
    the excuse that this was caused by datacheck errors in the brain
    after a long night's slaving over a hot terminal.

-------------------------------------------------------------------------
Tom Wade                      Bitnet:   twade@csvax.ucd.hea.irl
Systems Programmer            Ean:      twade@csvax.ucd.irl
Dept Computer Science         PSI:      PSI%+27243154000721::TWADE
University College Dublin     Telex:    (0500) 91196 UCD EI
Ireland.                      Uucp:     !mcvax!euroies!twade%csvax.ucd.hea.irl
                          Voice:    +353-1-693244 Ext 2472
-------------------------------------------------------------------------

