isastream - test a file descriptor (STREAMS)
The isastream() function shall test whether fildes, an open file descriptor, is associated with a STREAMS-based file.
Upon successful completion, isastream() shall return 1 if fildes refers to a STREAMS-based file and 0 if not. Otherwise, isastream() shall return -1 and set errno to indicate the error.
The isastream() function shall fail if:
- The fildes argument is not a valid open file descriptor.
The Base Definitions volume of IEEE Std 1003.1-2001, <stropts.h>
First released in Issue 4, Version 2.
Moved from X/OPEN UNIX extension to BASE.