isastream(3C)                                                 isastream(3C)


   NAME
         isastream - test a file descriptor

   SYNOPSIS
         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).
         in the Programmer's Guide: STREAMS






























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