Types of C and C++ input and output

A stream is a flow of data elements that are transmitted or intended for transmission in a defined format. A record is a set of data elements treated as a unit, and a file (or data set) is a named set of records that is stored or processed as a unit.

The z/OS® XL C/C++ compiler supports four types of input and output: text streams, binary streams, record I/O, and blocked I/O. Text and binary streams are both ANSI standards; record I/O and blocked I/O are extensions for z/OS XL C. Record I/O and blocked I/O are not supported by either the USL I/O Stream Class Library or the Standard C++ I/O stream classes.
Note: If you have written data in one of these four types and try to read it as another type (for example, reading a binary file in text mode), you may not get the behavior that you expect.