58 lines
2.1 KiB
TeX
58 lines
2.1 KiB
TeX
\chapter{Time and Daytime}\label{cha:ntp}
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Many Unix hosts provide a RFC~867 Daytime service which sends the
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current date and time as a human-readable character string. The
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daytime service is typically served on port 13 as both TCP and UDP.
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The RFC~868 Time protocol provides a site-independent, machine
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readable date and time. The Time service is typically served
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on port 37 as TCP and UDP. The idea is that you can confirm your
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system's idea of the time by polling several independent sites on the
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network.
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\section{Daytime}
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The \ex{rfc867} structure contains an interface to Daytime protocol.
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\defun{rfc867-daytime/tcp}{host}{string}
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\defunx{rfc867-daytime/udp}{host [timeout-or-\sharpf]}{string-or-\sharpf}
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\begin{desc}
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These procedures asks \var{host} about the current daytime and
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return the host's answer (e.g., ``Thursday, April 4,
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2'').
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\ex{Rfc867-daytime/tcp} uses the TCP variant of the protocol.
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\ex{Rfc867-daytime/udp} uses UDP and sends a single request to the
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server. It allows the specification of an optional timeout; if not
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specified or \sharpf{}, \ex{Rfc867-daytime/udp} will wait
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indefinitely for an answer. If the answer from the server doesn't
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arrive within the specified time, \ex{rfc867-daytime/udp} returns
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\sharpf.
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\end{desc}
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\section{Time}
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The \ex{rfc868} structure contains an interface to the Time protocol.
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\defun{rfc868-time/tcp}{host}{string}
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\defunx{rfc868-time/udp}{host [timeout-or-\sharpf]}{string-or-\sharpf}
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\begin{desc}
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These procedures asks \var{host} about the current time and return
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the host's answer. This is the number of second since 1970, just as
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with scsh's \texttt{time} procedure.
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\ex{rfc868-time/tcp} uses the TCP variant of the protocol.
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\ex{rfc868-time/udp} uses UDP and sends a single request to the
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server. It allows the specification of an optional timeout; if not
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specified or \sharpf{}, \ex{rfc868-time/udp} will wait
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indefinitely for an answer. If the answer from the server doesn't
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arrive within the specified time, \ex{rfc868-time/udp} returns
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\sharpf.
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\end{desc}
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%%% Local Variables:
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%%% mode: latex
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%%% TeX-master: "man"
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%%% End:
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