CIW Input Commands

The input line in the CIW holds the text of the current prompt until it is ready to be input. The command line text accumulates in the command input area, and a single event, usually typing a carriage return, triggers command execution.

Mouse and Keyboard Inputs

The CIW is activated by your keystrokes or mouse actions, just as the other windows are. All function keys, control keys, and mouse buttons are user configurable in any window. All alphanumeric or symbol character keystrokes have a literal meaning. It is a good idea to avoid binding any alphanumeric or symbol character keys to a command in the CIW.

The interpretation of keyboard and mouse actions depends on the application type of the window. All keys including function and control keys and mouse buttons are user-friendly in any window. Pressing a key submits a user-defined SKILL command string to the CIW for evaluation.

Input Prompt

When system initialization is complete, SKILL sends a prompt message to the prompt line and waits for an input event to occur. You can choose a different prompting style through the SKILL function setPrompts. If you change the prompt styles, the SKILL function is evaluated for each prompt. SKILL remains inactive until the command line message is received.

Parse Command Line

When a complete command line is received, it is parsed by SKILL. Arguments for SKILL functions are type checked against a template. All reasonable checking must be done at this level in the interests of consistency and economy of coding by the individual functions. All functions are executed according to the precedence of the SKILL command language.

Command Output Results

When a command line is received, SKILL sends the command language message to the output subwindow and to the transcript log. The result of the command is also written to the transcript log and possibly to the command output subwindow, depending on the setting of the log filter flags.

When a command runs successfully, the result is printed to the transcript log and possibly to the output subwindow.

Error Recovery

If an error is detected while evaluating a SKILL command, the standard error handler formats and generates a message before returning to the top level. This behavior can be modified by the use of errSet and errSetString within your SKILL program.

With the SKILL Development product, the standard error handler prints the contents of the SKILL stack and leaves you in a nested command interpreter to allow debugging. This includes detailed examination of the stack, and printing and modification of local variables. This nested interpreter runs using the same CIW windows as the top-level command interpreter. It is possible to switch between this and the non-development error handler.

If either of the standard error handlers are inappropriate, you can define your own with the SKILL Development product.

Interrupts

Interrupts are treated as errors. Execution resumes after an interrupt if you use the default error handler. The exception to this rule is Control+C, which always terminates the execution of the current SKILL command.

Nesting Commands

You can type a command in the CIW that prompts for more data, type another command that supports nesting, and then complete your first command. With command nesting you can gather additional data; the system supports multiple levels of command nesting. The default is one level, with a user-definable maximum of three levels of nesting.

Related Topics

General Environmental Functions

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