AT&T UNIX™PC Unix System V Users Manual - tenox

LAYERS (l) LAYERS (!)
NAME
layers - layer multiplexor for windowing terminals
SYNOPSIS
layers [-s] [-t] [-d] [-p] [-f file] [layersys-prgm]
DESCRIPTION
layers manages asynchronous windows (see layers(5)) on a windowing
terminal. Upon invocation, layers finds an unused xt(7) channel group
and associates it with the terminal line on its standard output. It then
waits for commands from the terminal.
Command-line options:
-s Reports protocol statistics on standard error at the end of the
session after you exit from layers. The statistics may be printed
during a session by invoking the program xts(lM).
-t Turns on xt(7) driver packet tracing, and produces a trace
dump on standard error at the end of the session after you exit
from layers. The trace dump may be printed during a session
by invoking the program xtt(lM).
-d If a firmware patch has been downloaded, prints out the sizes
of the text, data, and bss portions of the firmware patch on
standard error.
·
-p If a firmware patch has been downloaded, prints the downloading
protocol statistics and a trace on standard error.
-ffile Starts layers with an initial configuration specified by file.
Each line of the file represents a layer to be created, and has
the following format:
origin x origin -y corner x corner
_
y
command list
The coordinates specify the size and position of the layer on
the screen in the terminal's coordinate system. If all four are 0,
the user must define the layer interactively. command list, a
list of one or more commands, must be provided. It is executed
in the newlayer using the user's shell (by executing: $SHELL -i
-c "command list"). This means that the last command should
invoke a shelf, such as lbinlsh. (If the last command is not a
shell, then, when the last command has completed, the layer ·
will not be functional.)
layersys-prgm
A file containing a firmware patch that the layers command
downloads to the terminal before layers are created and
command list is executed.
Each layer is in most ways functionally identical to a separate terminal.
Characters typed on the keyboard are sent to the standard input of the
UNIX system process attached to the current layer (called the host process),
and characters written on the standard output by the host process
appear in that layer. When a layer is created, a separate shell is established
and bound to the layer. If the environment variable SHELL is set,
the user will get that shell: otherwise, lbinlsh will be used. In order to
enable communications with other users via write(!), layers invokes the
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