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10.0 Scripting Facilities
There are several scripting facilities that can be used with McIDAS to create and display products and prompt the user for input.

ASK1

The command ASK1 defines a question that prompts the user for a value which is entered into the string named by ASK1.

BATCH facility

The McIDAS BATCH allows users to serially execute a sequence of McIDAS commands that are stored in a text file. BATCH is loosely modelled after the DOS/OS/2 batch facility. It supports the passing of up to 9 parameters on the invocation line. There is rudimentary logical flow control available in the BATCH file. BATCH provides full access to the system string and key tables. Command execution stops at the end of the file or if any of the commands in the file fail. An example of a BATCH file used by the Unidata F Key Menu system is BKGMAP.BAT which is used to define and display various map types including the default background map.

RUN (McBASI)

The RUN command can be used to execute a McBASI script. McBASI is a BASIC-like interpreted scripting language available in McIDAS. The script is a set of McBASI commands stored in a text file. McBASI provides full access to the system tables and data files and has read/write access to User Common. It has string manipulation functions and trigonometrics functions.

A simple McBASI script is illustrated in the LBDR.MCB script that is used by the Fkey menu for setting image loop bounds and dwell times.

The McBASI script CFILLCLP.MCB runs a series of ADDE commands to get information about user-specified grid in a GRID file; copy the grid to a local dataset; convert the grid representation of the data into image format; use the topography images included in the Unidata McIDAS distribution to create a land-sea mask; and finally to visualize the transformed data as an image.

GEWCOMP.MCB and GEWCOMP1.MCB can be used to combine the GOES-East and West images (VIS, IR, or WV) into a single image. The routines use two different approaches to creating the composite image.

Tcl/Tk

Tcl/Tk is a UNIX scripting facility that provides high-level access to the X Window system. It is used with the McIDAS-X F Key menu system to prompt the user for input and display textual information. Tcl/Tk has full logical flow control and looping. It has the capability of X Window widget creation. Tcl/Tk is being used by Unidata and SSEC to build the next generation McIDAS Graphical User interface. The file strnvals.gui is an example of a Tcl/Tk script used by the Unidata F Key Menu system.

UNIX shell scripts

McIDAS commands do not need a running McIDAS-X session to execute; users can perform McIDAS processing directly from Unix shell scripts. In addition, the execution of these scripts can be initiated by the Unix time-based cron facility.

McIDAS commands run in Unix shell scripts need, however, to have a common environment to interact with each other. This environment is provided by the McIDAS mcenv facility. In the absence of a common execution environment, each McIDAS command would create, operate in, and then remove their own mini McIDAS session.

The Unidata McIDAS distribution contains several examples of Unix Bourne shell scripts that run one or more McIDAS commands. mcscour.sh is intended to be used for daily scouring of McIDAS-XCD produced data files.

mcbatch.sh is included as a template that users are encouraged to copy and use as a basis for running McIDAS BATCH files outside of an existing McIDAS session. Likewise, mcrun.sh is included as a template for running a sequence of McIDAS commands outside of a McIDAS session.

 


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