Use

Use

The USE command selects the current device for READs (input) and WRITEs (output).

The format of the USE command is:

U[SE][:tvexpr] expr[:(keyword[=expr][:...])][,...]

• The optional truth-valued expression immediately following the command is a command postconditional that controls whether or not GT.M executes the command.
• The required expression specifies the device to make the current device.
• A USE that selects a device not currently OPENed by the process causes a run-time error.
• The optional keywords specify deviceparameters that control device behavior; some deviceparameters take arguments delimited by an equal sign (=); if the argument only contains one deviceparameter, the surrounding parentheses are optional.
• An indirection operator and an expression atom evaluating to a list of one or more USE arguments form a legal argument for a USE.