Caché ObjectScript Reference - InterSystems Documentation

Caché ObjectScript CommandsThe parameters available with the USE command are highly device-dependent. In manycases the available parameters are the same as those available with the OPEN command;however, some device parameters can only be set using the OPEN command, and other canonly be set using the USE command.The USE command can specify more than one useargument, separated by commas. However,you can only have one current device at a time. If you specify more than one useargument,the device specified in the last useargument becomes the current device. This form of USEmay be used to set parameters for several devices, and then establish the last-named deviceas the current device.ArgumentspcAn optional postconditional expression. Caché executes the command if the postconditionalexpression is true (evaluates to a non-zero numeric value). Caché does not execute the commandif the postconditional expression is false (evaluates to zero). For further details, referto Command Postconditional Expressions in Using Caché ObjectScript.deviceThe device to be selected as the current device. Specify the same device ID (or other deviceidentifier) as you specified in the corresponding OPEN command. For more information onspecifying devices, refer to the OPEN command.parametersThe list of parameters used to set operating characteristics of the device to be used as thecurrent device. The enclosing parentheses are required if there is more than one parameter.(It's good programming practice to always use parentheses when you specify a parameter.)Note the required colon before the left parenthesis. Within the parentheses, colons are usedto separate multiple parameters.The parameters for a device can be specified using either positional parameters or keywordparameters. You can also mix positional parameters and keyword parameters within the sameparameter list.In most cases, specifying contradictory, duplicate, or invalid parameter values does not resultin an error. Wherever possible, Caché ignores inappropriate parameter values and takesappropriate defaults.The available parameters are, in many cases, the same as those supported for the OPENcommand. For sequential files, TCP devices, and interprocess communication pipes some146 Caché ObjectScript Reference