CLOSE(2-SVR4)       RISC/os Reference Manual        CLOSE(2-SVR4)



NAME
     close - close a file descriptor

SYNOPSIS
     #include <unistd.h>
     int close(int fildes);

DESCRIPTION
     fildes is a file descriptor obtained from a creat, open,
     dup, fcntl, or pipe system call.  close closes the file
     descriptor indicated by fildes.  All outstanding record
     locks owned by the process (on the file indicated by fildes)
     are removed.

     When all file descriptors associated with the open file
     description have been closed, the open file description is
     freed.

     If the link count of the file is zero, when all file
     descriptors associated with the file have been closed, the
     space occupied by the file is freed and the file is no
     longer accessible.

     If a STREAMS-based [see intro(2)] fildes is closed, and the
     calling process had previously registered to receive a SIG-
     POLL signal [see signal(2)] for events associated with that
     stream [see I_SETSIG in streamio(7)], the calling process
     will be unregistered for events associated with the stream.
     The last close for a stream causes the stream associated
     with fildes to be dismantled.  If O_NDELAY and O_NONBLOCK
     are clear and there have been no signals posted for the
     stream, and if there are data on the module's write queue,
     close waits up to 15 seconds (for each module and driver)
     for any output to drain before dismantling the stream.  The
     time delay can be changed via an I_SETCLTIME ioctl request
     [see streamio(7)].  If O_NDELAY or O_NONBLOCK is set, or if
     there are any pending signals, close does not wait for out-
     put to drain, and dismantles the stream immediately.

     If fildes is associated with one end of a pipe, the last
     close causes a hangup to occur on the other end of the pipe.
     In addition, if the other end of the pipe has been named
     [see fattach(3C)], the last close forces the named end to be
     detached [see fdetach(3C)].  If the named end has no open
     processes associated with it and becomes detached, the
     stream associated with that end is also dismantled.

     The named file is closed unless one or more of the following
     are true:

     EBADF          fildes is not a valid open file descriptor.




                        Printed 11/19/92                   Page 1

CLOSE(2-SVR4)       RISC/os Reference Manual        CLOSE(2-SVR4)



     EINTR          A signal was caught during the close system
                    call.

     ENOLINK        fildes is on a remote machine and the link to
                    that machine is no longer active.

SEE ALSO
     creat(2), dup(2), exec(2), fcntl(2), intro(2), open(2),
     pipe(2), signal(2), signal(5).
     streamio(7) in the System Administrator's Reference Manual.

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Oth-
     erwise, a value of -1 is returned and errno is set to indi-
     cate the error.








































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