| 1 | .TH SELECT 2 "Jun 9, 2005"
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| 2 | .UC 4
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| 3 | .SH NAME
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| 4 | select, FD_CLR, FD_ISSET, FD_SET, FD_ZERO \- synchronous I/O multiplexing
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| 5 | .SH SYNOPSIS
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| 6 | .nf
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| 7 | .ft B
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| 8 | #include <sys/select.h>
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| 9 |
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| 10 | int select(int \fInfds\fP, fd_set *\fIreadfds\fP, fd_set *\fIwritefds\fP, fd_set *\fIerrorfds\fP, struct timeval *\fItimeout\fP)
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| 11 |
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| 12 | void FD_CLR(int \fIfd\fP, fd_set *\fIfdset\fP)
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| 13 | int FD_ISSET(int \fIfd\fP, fd_set *\fIfdset\fP)
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| 14 | void FD_SET(int \fIfd\fP, fd_set *\fIfdset\fP)
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| 15 | void FD_ZERO(fd_set *\fIfdset\fP)
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| 16 | .ft R
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| 17 | .fi
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| 18 | .SH DESCRIPTION
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| 19 | .B Select
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| 20 | examines the file descriptors given in the sets
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| 21 | .IR readfds ,
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| 22 | .IR writefds ,
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| 23 | and
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| 24 | .IR errorfds ,
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| 25 | up to and including file descriptor
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| 26 | .IR nfds -1
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| 27 | , for reading, writing, or exceptional conditions, respectively.
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| 28 | .B Select
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| 29 | currently supports regular files, pipes, named pipes,
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| 30 | inet, and tty file descriptors (including pty).
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| 31 |
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| 32 | If the
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| 33 | .I readfds
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| 34 | argument is not a null pointer, it points to an object of type fd_set
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| 35 | that on input specifies the file descriptors to be checked for being
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| 36 | ready to read, and on output indicates which file descriptors are ready
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| 37 | to read.
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| 38 | .I Writefds
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| 39 | and
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| 40 | .I errorfds
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| 41 | have an analogous meaning for file descriptors to be checked for being
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| 42 | ready to read, respectively have pending exceptional (error) conditions.
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| 43 |
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