PPT Slide
Direct access input and output
The connection of a file to a unit has an access method, which is sequential or direct. Direct access means that records may be accessed in an arbitrary sequence. Each record of the file has a unique record number that is established when the record is written and does not change. A Record number specifier in the Control List of each read or write statement indicates which record is to be read or written; this specifier has the form
Record number is an integer expression with a positive value.
Example for direct access output statement:
write (unit = 3, fmt = *, rec = 76) X, Y, Z, Z5
- write statement sends information to record number 76 of unit 3.