MultiView Mascot Support

Running MultiView Mascot with Specific Pseudo Devices

By design, MultiView Mascot is written so that as users open windows/applications the next available psuedo tty is grabbed and used. For most applications this is not a problem. However, some applications (notably BBx) require configuration files which specify pseudo devices to be used and the attributes for those devices. For those cases, MultiView Mascot can be configured so that it meets both of these requirements.

This document gives the example of a user who needs to be able to run up to three copies of bourne shell simultaneously and also needs to specify the /dev file they will run on.

The system administrator will put a copy of the .mvw_usermenu file (and also of the .mvw_startup file if they start the applications automatically) in each user’s home directory.

The following example shows the edited .mvw_usermenu file.

##

## ***************************************

## The Mascot default USER command file.

## ***************************************

##

##

##

#RootMenu

" Root Menu " f.title

" &Clients -> " f.menu ClientsMenu

" &WordPerfect " f.exec /jsbshare/wp/wpbin/wp

" &Shell Copy1 " -Ltom1 f.exec /bin/sh

" &Shell Copy2 " -Ltom2 f.exec /bin/sh

" &Shell Copy3 " -Ltom3 f.exec /bin/sh

" Shuffle &Up " f.circle_up

" Shuffle &Down " f.circle_down

" &Refresh " f.refresh

no-label f.separator

The -L flag links the name specified directly after it to the psuedo-tty which it will run in. So, if we run MultiView Mascot and open up Shell Copy 1, we can look at the process and see:

$NODENAME:$PWD =>ps -ef | grep 3307

deniseh 3307 3278 2 10:18:50 p5 0:01 mascot

deniseh 3310 3307 1 10:18:55 p8 0:00 /bin/sh

Further, if we then look at the files in the /dev directory we can see:

$NODENAME:$PWD =>l /dev/ttyp8

crw-rw-rw- 2 deniseh group 58, 8 Jun 11 10:20 /dev/ttyp8

which was the next available psuedo tty available. However, if we look further we will see:

$NODENAME:$PWD =>l /dev/tom1

crw-rw-rw- 2 deniseh group 58, 8 Jun 11 10:19 /dev/tom1

The number 2 indicates that there are two files with the same inode (therefore are linked) and those two are /dev/tom1 and /dev/ttyp8 (confirmed by the major and minor numbers being the same). The file tom1 is created dynamically in the /dev directory when the /bin/sh application is opened. After the application is closed there will be no /dev/tom1. It will simply be recreated the next time this item is started and it may link to a totally different psuedo-device the next time.

For an application like BBx, you would then set up the configuration file based on /dev/tom1, /dev/tom2, etc. NOT ttypx.

The most important point about running the file name links is that each process must have a UNIQUE file name. If you had Shell Copy #2 also opening a /dev file called tom1 and it already existed, the process would fail to open.