@begin(header)
author: Eric Mandel
show_author: ShowNone
author_organization: Smithsonian Astrophysical Observatory
node_expert: eric@cfa.harvard.edu
expiration_date: 12/31/93
last_modifier: eric@cfa.harvard.edu
last_mod_date: 11/13/92
mod_num: 3
@end(header)
@b<This window will tell you how to place simple one-line commands in the top-level tree of the ASSIST.>

Sometimes it is useful to be able to execute commands that do not have
parameters associated with them. Such commands are more amenable to a
push-button interface than are parameter-based programs, which require
a parameter editor (or something similar).

In IRAF, examples of this type of command are: @break

	= gcur			enter graphics cursor mode @break
	    q			exit graphics cursor mode

In the host system (i.e., Unix), an example of this type of command is: @break

	SAOimage -pros	PROS mode display

The ASSIST supports this type of command through the "one-liner"
facility, which consists of two grapher trees named @b<IRAF
One-Liners> and @b<Host One-Liners>.  These grapher trees are
maintained at the top-level of the ASSIST tree and contain one-line
IRAF and host commands, respectively.  Each command is represented by
a command button.  Pressing the @b<left> mouse button on such a
command button will send the command to the proper target analysis
window for execution.

You can specify your own one-line IRAF and host commands that will
appear in these top-level packages by placing these commands in files
called @b<user.irafcmds> and @b<user.hostcmds> in your @b<uparm>
directory.  When one of these entries is activated with the @b<left>
mouse button, the command will be sent to the correct target window.

Text explanations can be added to these files by placing an IRAF
comment character, @b<#>, at the beginning of a line.  Non-commented
lines are assumed to be one-line commands. For example, consider the
following @b<user.irafcmds> file: @break

	# To display QPOE files in this directory: @break
	dir *.qp long+ @break
	# delete .tmp files in the current directory: @break
	delete *.tmp @break

This file will add a few lines of explanatory text and 2 buttons to
the @b<IRAF One-Liners> grapher tree.  By clicking on a command
button, the appropriate command is sent to the target analysis window
for execution.

Note that the characters seven "{[<>]}," are reserved characters used
by ASSIST to delineate the one-line commands.  There is currently no
way to input these characters into a one-line command string.  This
restriction will be lifted in a future revision of ASSIST.