XIMAGE is a command-driven program. Each command has associated with it qualifiers and positional parameters which define parameters to be passed to each XIMAGE command. Qualifiers and positional parameters be of three different types, numerical, character and logical. Qualifiers are preceded by a slash /. Numerical and character qualifiers must be used as follows command/qualifier= the parameter value or the appropriate alphanumeric string must be given after the symbol ``=". Logical qualifiers can be used simply by specifying their name (i.e. command/logical). Qualifier names can be abbreviated provided that the abbreviation is unique. To get a list of the available qualifiers for each command type command/?. Positional parameters follow the qualifiers and are typically used to specify a required parameter e.g. command pos1. Up to ten commands can be typed on the same line using the symbol ; as a separator. The commands are executed in sequence from left to right.
Commands can be given at the XIMAGE> prompt or, equivalently, as a command string when XIMAGE is started. The following two examples will produce the same result:
$ XIMAGE [1]XIMAGE>read/fits test.fits [2]XIMAGE>disp [3]XIMAGE>exit $ XIMAGE read/fits test.fits; disp; exit`In both cases the user asks to run XIMAGE, read the image test.fits, display it and then return to the operating system.
The command recall is used to list previous commands. Any command can be reexecuted by typing recall n where n is the command number given in the listing. The alias command is used to rename long command strings to a simple name. A log file of the session can be created using log file. This will create a text file called file.log.
Scripts (Macros) can be created in a text file with the extension .xco. They are run by giving the file name preceded by an @ symbol at either the XIMAGE prompt, or at run time e.g. ximage @my_analysis [P1] [P2]. Variables can be passed into the script by using %N% in the script, where N is the number of the parameter on the command line. E.g. the my_analysis script could be
read/fits %1% disp read/fits %2% dispWhere P1 and P2 are the filenames. If P1 and P2 are not given on the command line, then the user will be prompted for them. To prompt for parameters from a script use the @ symbol.
The operating system can be accessed from the XIMAGE command line by preceding the command with a $ symbol e.g. $ls. Typing a $ symbol on its own will spawn to the operating system command line, without interupting the current ximage session. Type exit to return to XIMAGE.