Debugger variables are pseudovariables that exist within the debugger instead of within your program. They have the following uses:
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Support some limited programming capabilities within the debugger command language
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Allow you to examine and change various debugger options
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Allow you to find out exactly what various debugger commands did
Debugger variables fall into one of the following categories:
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User-defined variables |
You create these and can set them to a value of any type. |
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Preference variables |
You modify these to change debugger behavior. You can only set a preference variable to a value that is valid for that particular variable. |
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Display/state variables |
These variables display the parts of the current debugger state. You cannot modify them. |
You can delete and redefine the predefined debugger variables in the same way you define your own variables.
If you delete a predefined debugger variable, the debugger uses the default value for that variable.
The following commands deal specifically with debugger variables:
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set [variable]
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unset
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help "variable"
The debugger variable name should not exist anywhere in your program, or you may confuse yourself about which of the occurrences you are actually dealing with. The predefined debugger variables all start with a dollar sign ($), to help avoid this confusion. It is strongly recommended that you follow the same practice. In a future release, all user-defined debugger variables will be required to start with a dollar sign.
Note
If a debugger variable exists that shares a name with a program variable, and you print an expression involving that name, which of the two variables the debugger finds is undefined.