The isastream() function determines if a file descriptor represents a STREAMS file. The fildes argument refers to an open file descriptor.

Upon successful completion, isastream() returns 1 if fildes represents a STREAMS file, and 0 if it does not. Otherwise, -1 is return and errno is set to indicate the error.

The isastream() function will fail if:

EBADF

The fildes argument is not a valid file descriptor.

See attributes(5) for descriptions of the following attributes:

attributes(5), streamio(7I)

STREAMS Programming Guide