NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/comp/os/vms/21605

Text File | 1993-01-21 | 2.3 KB | 65 lines

Newsgroups: comp.os.vms
Path: sparky!uunet!ulowell!woods.ulowell.edu!sabotkap
From: [e-mail]
Subject: Re: mailboxes with DCL?
Message-ID: <[e-mail]>
Lines: 53
Sender: [e-mail] (News manager - ulowell)
Organization: University of Lowell
References: <[e-mail]>
Date: Thu, 21 Jan 1993 07:18:20 GMT

[e-mail] (Framstag) requests:
->
->  Some (easy, of course :-) ) examples of DCL programs handling with
->  mailboxes with normal user privs (netmbx,tmpmbx).
->

The following hack DCL procedure opens a channel to the mailbox created
during a SPAWN, and keeps it open after the subprocess terminates.
Note that processes reading/writing this mailbox could very easily end up
hung waiting for the other processes' read/write, if the command procedures
you are using to do the communications are not synchronized.  Also, you
will not be able to set the buffer size, protection mask, or other flags.
All attributes of the mailbox are initialized when it is created via a
SPAWN.

^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v^-v-^
Pete Sabotka, Meteorology Dept.                   [e-mail]
University of Massachusetts - Lowell
"Days like this let you savor a bad mood."        - Calvin (Calvin & Hobbes)
^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v-^-v^-v-^
$!    CREMBX.COM
$!    Creates a mailbox for DCL use
$!
$!    parameters:  p1 - logical name to open for mailbox
$!
$ if p1 .eqs. "SUB" then goto subprocess
$Mainprocess:
$ channel=p1
$ if channel .eqs. "" then read sys$command channel/end=done/prompt="_Log name: "
$ if channel .eqs. "" then goto Mainprocess
$ program=f$environment("procedure")
$ parent_pid=f$getjpi(0,"pid")
$ spawn/nolog/nowait @'program' SUB 'parent_pid'
$ set process/suspend/id=0
$ spawn_pid=f$trnlog("SPAWN_PID")
$ mbxnum=f$trnlog("MBXNUM")
$ mailbox="MBA''mbxnum':"
$ open/read/write 'channel' 'mailbox'
$ stop/id='spawn_pid'
$ deassign/job SPAWN_PID
$ deassign/job MBXNUM
$ w "Mailbox device ''mailbox' opened"
$Done:
$ exit
$Subprocess:
$ spawn_pid=f$getjpi(0,"pid")
$ if p2 .nes. "" then resume_pid=p2
$ mbxnum=f$getjpi(0,"TMBU")
$ define/job/nolog SPAWN_PID 'spawn_pid'
$ define/job/nolog MBXNUM 'mbxnum'
$ set process/resume/id='resume_pid'
$ set process/suspend/id=0