isastream(3C)

NAME
     isastream - test a file descriptor

SYNOPSIS
     #include <sys/stropts.h>
     int isastream(int fildes);

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

RETURN VALUE
     If successful, isastream() returns 1 if fildes represents a STREAMS file,
     and 0 if not.  On failure, isastream() returns -1 with errno set to
     indicate an error.

ERRORS
     Under the following conditions, isastream() fails and sets errno to:

     EBADF        fildes is not a valid open file.

SEE ALSO
     streamio(7)