SKYMAP 4. User Interface

There are four ways to interact with skymap: parameter file editing, command line, menu/prompt, and cursor. Parameters which define a skymap session are stored in an ASCII parameter file, the format of which is described in Appendix A, "Simple ASCII Parameter Files". These files contain one parameter per line in the format
	keyboard = value   / comment
and can be edited using any Unix editor. A default parameter file is moved into the current working directory when skymap is invoked there for the first time. All interaction modes modify the working parameter file. Appendix B gives definitions for all parameters currently in use.

Unix Shell

The menu subroutine can be totally bypassed by setting the MENU parameter false; skymap will then plot directly from the Unix shell. For example, typing
	skymap menu
will return T if the MENU=T, and F if MENU=F and PARVAL=Y, the default value. If PARVAL=N, the parameter names are included. For example,
	skymap menu cursor
	MENU=T [If true, menu prompts appear]
Comments from the parameter file are included if they are present. The CURSOR parameter will cause the program to stop in cursor mode after plotting if it is set true. Parameter values may be changed on the command line by typing
	skymap keyword1=value1 keyword2=value2 ...
.as described in Appendix A. Because arithmetic on parameters is possible, Unix shell scripts can be written for repeated operations. skymap may be run from an alternate parameter file by typing
	skymap -par parameter file name

Command Line

All skymap parameters may be set on the command line by simply typing:
	skymap keyword1=value1 keyword2=value2 ...
To check keyword values, you simply type
	skymap keyword1 keyword2 ...
If the PARVAL parameter is set to true,

Appendix C lists those parameters which may be set using a more typical Unix method: - . Many of them are listed with their current values when you type skymap help. To set parameters without plotting a map or entering menu selections or to simply get the default parameter file, add -stop to the command line, and skymap will process the preceding parameter entries on the command line and return to the Unix shell.


The menu system is a user-friendly, fairly bomb-proof interface perfected over the past ten years. There are several levels of menu. The top level handles action commands, parameter file actions, and selection of submenus. The submenus handle information concerning source catalogs, planets, mapping, image characteristics, IRT scan data, display format, and image operations. A single keyboard character chooses the menu selection; the main menu is not displayed unless a space is entered in response to the top level prompt,
Appendix D describes the available menu selections.

A list of commands at the top level is available by typing a or ?. Lists of submenu commands can be obtained by responding with a space or ? after the submenu is selected. An = in response to most submenu prompts lists the values of all of the parameters which can be set within that submenu. Prompts requiring a single character response end in : or ?, while those needing a for termination of the response end in =. Both and delete the previous character typed. prints the current value without entering it (even for : prompts). retypes the prompt and the current response. with no new response displays keeps the current value. Out of range numbers and illegal characters are trapped, and the prompt is repeated.


The cursor command set is based on the Tektronix GIN mode which is available to a wide variety of graphics terminals, including the graphics window of xterm under the X window system. When cursor mode is chosen by the K command or CURSOR=T, a cursor appears on the screen. When it is moved to the appropriate position using a mouse or other pointing device, a single keyboard character selects the use to which the cursor coordinates will be put. Image scaling and pixel values, map zooming and coordinates, and source identifications are available in this way. A menu of cursor commands appears when a space or ? is entered. Appendix F lists the available cursor commands.

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