shl(1)shl(1)NAMEshl - shell layer manager
SYNOPSISDESCRIPTION
provides a means for interacting with more than one shell from a single
terminal by using shell layers. A layer is a shell that is bound to a
virtual device. The virtual device can be manipulated like an actual
terminal by using and (see stty(1) and ioctl(2)). Each layer has its
own process group ID. The user controls these layers by using the com‐
mands described below.
The current layer is the layer that can receive input from the key‐
board. Other layers attempting to read from the keyboard are blocked.
Output from multiple layers is multiplexed onto the terminal. To block
the output of a layer when it is not current, the option can be set
within the layer.
The character (set to if NUL) is used to switch control to from a
layer. has its own prompt, to distinguish it from a layer.
Definitions
A is a sequence of characters delimited by a space, tab, or new-line
character. Only the first eight characters are significant. When pro‐
vided as an argument to the or commands, name cannot be of the form n
or where n is a decimal number.
Commands
The following commands can be issued from the prompt level. Any unique
prefix is accepted.
Create a layer called
name and make it the current layer. If no argument is
given, a layer is created with a name of the form where
n is the number of the next available slot in an inter‐
nal table. Future references to this layer can be made
with or without the parentheses. If name is followed by
a command, that command is executed in the layer instead
of a shell. If is the first argument, a ``login shell''
is created in the layer. The shell prompt variable is
set to the name of the layer followed by a space.
Rename the layer
oldname, calling it newname. If oldname is not speci‐
fied, the current layer name is changed.
Invoke a sub-shell and execute
command. If no command is given, a shell is executed
according to the environment variable.
For each name, block the output of the corresponding layer when
it is not the current layer. This is equivalent to set‐
ting the option within the layer.
For each name, delete the corresponding layer. All processes in
the process group of the layer are sent the signal (see
signal(5)).
Print the syntax of the
commands.
For each name, list the layer name and its process group. The
option produces a ps(1)-like listing. If no arguments
are given, information is presented for all existing
layers.
Change the status of the layer referred to by
name to that of current layer. If no argument is given,
the last existing current layer is changed.
Change the status of the previous current layer
to that of current layer.
For each name, do not block the output of the corresponding layer
when it is not the current layer. This is equivalent to
setting the option within the layer.
Exit All layers are sent the signal.
name Change the status of the layer referred to by name to
that of current layer. Any unique prefix is accepted.
WARNINGS
Commands
The behavior of the and commands is not guaranteed when the SHELL envi‐
ronment variable is set to (for csh(1)) or (for ksh(1)), or when the
shell saves and restores the tty state (defined in termio(7)) before
and after each command is invoked interactively from that shell. For
both and the or options of can be used from within the layer to block
or unblock the output of that layer.
Ptydaemon
For to function properly, the process must be running on the system.
If your system has been installed with the Desktop HP-UX product, then
will not be started by default. In order to start this daemon, change
from a "0" to a "1" in the file. The system must either be rebooted
for this change to take effect, or you can manually start this daemon
by typing :
Note that will also be disabled if the DesktopConfig.LITECONFIG fileset
has been installed on the system, or if the system administrator has
previously run the utility and selected the from within any of screens.
does not support long user and group names on the current release, HP-
UX 11i V3.
FILES
Variable containing path name of the shell to use (default is
SEE ALSOsh(1), stty(1), ioctl(2), signal(5).
STANDARDS CONFORMANCEshl(1)
