It is not necessary that a data set accessed using stream-oriented data transmission was created by stream-oriented data transmission. However, it must have CONSECUTIVE organization, and all the data in it must be in character or graphic form. You can open the associated file for input, and read the items the data set contains; or you can open the file for output, and extend the data set by adding items at the end.
To access a data set, you must use one of the following to identify it:
When your application accesses an existing STREAM file, PL/I must obtain a record length value for that file. The value can come from one of the following sources:
If you are using an existing OUTPUT file, or if you supply a RECSIZE value, PL/I determines the record length value as described in Creating a data set with stream I/O.
PL/I uses a default record length value for an INPUT file when: