B. Defining Function and Control Keys : Key Mapping Overview (UNIX and VMS Environments) : Mapping Files (UNIX and VMS)
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Mapping Files (UNIX and VMS)
Typically, entries within mapping files define a connection between logical FRS mapping objects, which can be accessed by the forms system, and program function (pf) keys, control keys, and arrow keys on a keyboard.
There are different types of FRS mapping objects. A FRS object can be any one of the following:
FRS command
Menu item
An example of an FRS object is the FRS command menu. FRS commands are built‑in functions of the FRS, such as moving to the menu line or moving to the next field, that enable the user to view and edit the data on a form. The FRS defines the behavior of each FRS command. For instance, the menu command moves the cursor to the menu line.
A mapping file maps these functions to the function, control, and arrow keys that are defined for your terminal in the termcap file. The key mapping sequence in the mapping file and the termcap file can be depicted as follows:
In the mapping file as:
FRS mapping object = pf, control, or arrow key
In the termcap file as:
pf, control, or arrow key = escape sequence
For example, the key mapping sequence for the previous field command can be represented as follows:
In the mapping file as:
menu FRS command = pf1
In the termcap file as:
pf1 = escape sequence for pf1
The actual mapping statement in the FRS mapping file is:
menu = pf1 (PF1) /* Menu (menu key) */
The key name shown in parentheses is a label that indicates to the user which physical key to press. The functionality of each key mapping is shown as a comment statement between the characters /* and */.
This mapping scheme provides flexibility in assigning functions to keyboard keys, without requiring editing of the termcap file. You can easily assign any FRS mapping object to a different key by changing the mapping statement in the mapping file, or by overriding it with a statement in a mapping file of higher precedence. For more information, see Levels of Mapping (UNIX and VMS) (see page Levels of Mapping (UNIX and VMS)).