IML data processing commands work on the current data set. This feature makes it unnecessary for you to specify the data set as an operand each time. There are two current data sets, one for input and one for output. IML makes a data set the current one as it is opened. You can also make a data set current by using two setting statements, SETIN and SETOUT:
The USE and SETIN statements make a data set current for input.
The SETOUT statement makes a data set current for output.
The CREATE and EDIT statements make a data set current for both input and output.
If you issue a USE, EDIT, or CREATE statement for a data set that is already open, the data set is made the current data set. To find out which data sets are open and which are current input and current output data sets, use the SHOW DATASETS statement.
The current observation is set by the last operation that performed input/output (I/O). If you want to set the current observation without doing any I/O, use the SETIN (or SETOUT) statement with the POINT option. After a data set is opened, the current observation is set to 0. If you attempt to list or read the current observation, the current observation is converted to 1. You can make the CLASS data set current for input and position the pointer at the 10th observation with the following statement:
> setin class point 10;