Watchpoints

Watchpoints are used to monitor specified variables. The Watchpoint facility is used to designate a given variable to be watched. When the contents of the watched variable change, program execution stops and control is returned to the debugger. Watchpoints may be conditional and may have associated action lists (sequences of debugger commands to be executed when the watchpoint is incurred).

There are three pertinent commands to the Watch facility: WATCH, NWATCH, and LWATCH.

• The WATCH command is used for adding new watchpoints and modifying existing watchpoints.
• The NWATCH command removes either a specified watchpoint or all watchpoints.
• The LWATCH command lists information about watchpoints.