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Annotation of cci/usr/src/man/man2/select.2, revision 1.1

1.1     ! root        1: .TH SELECT 2 "2 July 1983"
        !             2: .UC 4
        !             3: .SH NAME
        !             4: select \- synchronous i/o multiplexing
        !             5: .SH SYNOPSIS
        !             6: .nf
        !             7: .ft B
        !             8: #include <sys/time.h>
        !             9: .PP
        !            10: .ft B
        !            11: nfound = select(nfds, readfds, writefds, execptfds, timeout)
        !            12: int nfound, nfds, *readfds, *writefds, *execptfds;
        !            13: struct timeval *timeout;
        !            14: .fi
        !            15: .SH DESCRIPTION
        !            16: .I Select
        !            17: examines the i/o descriptors specified by the bit masks
        !            18: .IR readfds ,
        !            19: .IR writefds ,
        !            20: and
        !            21: .I execptfds
        !            22: to see if they are ready for reading, writing, or have an exceptional
        !            23: condition pending, respectively.
        !            24: File descriptor 
        !            25: .I f
        !            26: is represented by the bit \*(lq1<<f\*(rq in
        !            27: the mask.
        !            28: .I Nfds
        !            29: desciptors are checked,
        !            30: i.e. the bits from 0 through
        !            31: .IR nfds -1
        !            32: in the masks are examined.
        !            33: .I Select
        !            34: returns, in place, a mask of those descriptors which are ready.
        !            35: The total number of ready descriptors is returned in
        !            36: .IR nfound .
        !            37: .PP
        !            38: If
        !            39: .I timeout
        !            40: is a non-zero pointer, it specifies a maximum interval to wait for the
        !            41: selection to complete.  If 
        !            42: .I timeout
        !            43: is a zero pointer, the select blocks indefinitely.  To affect a poll, the
        !            44: .I timeout
        !            45: argument should be non-zero, pointing to a zero valued timeval structure.
        !            46: .PP
        !            47: Any of
        !            48: .IR readfds ,
        !            49: .IR writefds ,
        !            50: and
        !            51: .I execptfds
        !            52: may be given as 0 if no descriptors are of interest.
        !            53: .SH "RETURN VALUE
        !            54: .I Select
        !            55: returns the number of descriptors which are contained in
        !            56: the bit masks,
        !            57: or \-1 if an error occurred.
        !            58: If the time limit expires then
        !            59: .I select
        !            60: returns 0.
        !            61: .SH "ERRORS
        !            62: An error return from \fIselect\fP indicates:
        !            63: .TP 15
        !            64: [EBADF]
        !            65: One of the bit masks specified an invalid descriptor.
        !            66: .TP 15
        !            67: [EINTR]
        !            68: An signal was delivered before any of the selected for
        !            69: events occurred or the time limit expired.
        !            70: .SH SEE ALSO
        !            71: accept(2), connect(2), read(2), write(2), recv(2), send(2)
        !            72: .SH BUGS
        !            73: The descriptor masks are always modified on return, even
        !            74: if the call returns as the result of the timeout.

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