4.13.6.3 Selecting special events to wait for

Function: select-fd-readable? fd sec usec

Function: select-port-readable? port sec usec

Interface to the C function select(), (libc)select. Wait for a readable event on the single file descriptor fd or port having a file descriptor as device. sec and usec must be fixnums representing timeout seconds and microseconds.

If the timeout expires before any event arrives: return #f. If an error occurs: raise an exception. Else return #t if the file descriptor becomes readable.

Function: select-fd-writable? fd sec usec

Function: select-port-writable? port sec usec

Interface to the C function select(), (libc)select. Wait for a writable event on the single file descriptor fd or port having a file descriptor as device. sec and usec must be fixnums representing timeout seconds and microseconds.

If the timeout expires before any event arrives: return #f. If an error occurs: raise an exception. Else return #t if the file descriptor becomes writable.

Function: select-fd-exceptional? fd sec usec

Function: select-port-exceptional? port sec usec

Interface to the C function select(), (libc)select. Wait for an exceptional event on the single file descriptor fd or port having a file descriptor as device. sec and usec must be fixnums representing timeout seconds and microseconds.

If the timeout expires before any event arrives: return #f. If an error occurs: raise an exception. Else return #t if the file descriptor receives an exceptional notification.