VSCREEN CLEAR

Authorization

General User

Purpose

Use the VSCREEN CLEAR command to erase data in a virtual screen.

Operands

vname

is the name of the virtual screen to be cleared.

Usage Notes

1. The VSCREEN CLEAR command:
   • Clears the scrollable data area by overwriting the data buffer with nulls
   • Purges data in the queue
   • Reconnects all windows connected to the virtual screen to the top of the virtual screen
   • Leaves the reserved areas and cursor position unchanged
2. The field attribute buffer and the extended attribute buffers for color, extended highlighting (exthi) and Programmed Symbol (PS) sets are reset to the default attributes as specified on the VSCREEN DEFINE and SET VSCREEN commands.
3. When a virtual screen is cleared, the lines in the scrollable data area are renumbered if necessary. Because of this, the cursor line number returned when QUERY CURSOR vname is issued immediately before VSCREEN CLEAR may be different from the cursor line number returned when QUERY CURSOR vname is issued immediately following VSCREEN CLEAR. The physical location of the cursor in the virtual screen remains unchanged.

Messages and Return Codes

• DMS386E Missing operand(s) [RC=24]
• DMS388E Invalid keyword: keyword [RC=24]
• DMS391E Unexpected operand(s): operand [RC=24]
• DMS921E Virtual screen vname is not defined [RC=28]
• DMS928E Command is not valid for virtual screen vname [RC=12]

Additional system messages may be issued by this command. The reasons for these messages and their location are: