7.4.61.1. Stream Commands

The following stream commands are used to:

Open a stream for reading, writing, or both.
Close a stream at the end of an operation.
Position the read or write position within a persistent stream (for example, a file).
Get information about a stream (its existence, size, and last edit date).

The stream_command argument must be used when—and only when--you select the operation C (command). The syntax is:

In this form, the STREAM function itself returns a string corresponding to the given stream_command if the command is successful. If the command is unsuccessful, STREAM returns an error message string in the same form as the D (Description) operation supplies.

For most error conditions, the additional information is in the form of a numeric return code. This return code is the value of ERRNO that is set whenever one of the file system primitives returns with a -1.