4.3BSD/usr/contrib/apl/doc/man.2

.NH 1
\*a System Commands
.PP
There are a number of
``system commands'' in \*a.
These commands are used
to control your current
session.
System commands
may be typed at any time
when \*a is prompting for input.
(They may not be included
in \*a functions, however.)
As stated previously,
when \*a is waiting for
input from the keyboard,
it will type eight spaces.
.PP
There are two types of
system commands,
those which request information
and those which specify action by \*a.
All system commands are preceeded
by a right parenthesis.
As an example,
the following is a typical
entry into \*a:
.sp
$ apl
.br
a p l \\ 1 1
.br
25 oct 1978
.sp
clear ws
.sp
	\_
.sp
(the underline character ``\_''
represents the ``cursor''
on the terminal).
The ``)lib'' command could then
be typed:
.sp
	)lib
.sp
.PP
Commands which specify action
are composed of the command
name
and some other value.
For instance,
to set the output width
(number of characters per line
that \*a will print)
to 64,
the command is:
.sp
	)width 64
.sp
.PP
A final warning \(em
the command name and the right
parenthesis must be together:
.sp
	) width 64
.sp
is invalid and will give an error message.
.PP
The available commands are described
fully in Appendix B.