56 lines
2.6 KiB
Plaintext
Executable File
56 lines
2.6 KiB
Plaintext
Executable File
ntpclient is an NTP (RFC-1305) client for unix-alike computers.
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Its functionality is a small subset of xntpd, but IMHO performs
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better (or at least has the potential to function better) within
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that limited scope. Since it is much smaller than xntpd, it is
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also more relevant for embedded computers.
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ntpclient is Copyright 1997, 1999, 2000 Larry Doolittle, and may
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be freely used and copied according to the terms of the GNU
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General Public License, version 2.
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ntpclient home page: http://doolittle.faludi.com/ntpclient/
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To build on Linux, type "make". Solaris and other Unix users will
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probably need to adjust the Makefile slightly. It's not complicated.
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Usage: ntpclient [options]
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options:
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-c count stop after count time measurements (default 0 means go forever)
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-d print diagnostics (feature can be disabled at compile time)
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-h hostname (mandatory) NTP server host, against which to measure system time
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-i interval check time every interval seconds (default 600)
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-l attempt to lock local clock to server using adjtimex(2)
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-p port local NTP client UDP port (default 0 means "any available")
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-r replay analysis code based on stdin
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-s simple clock set (implies -c 1)
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Mortal users can use this program for monitoring, but not clock setting
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(with the -s or -l switches). The -l switch has not been well tested.
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Simulation (with -r) actually looks halfway decent, so locking should be
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OK too, but it needs some tuning.
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The test.dat file has 200 lines of sample output. Its first few lines,
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with the output column headers that are shown when the -d option is
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chosen, are:
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day second elapsed stall skew dispersion freq
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51785 180.386 1398.0 40.3 953773.9 793.5 -1240000
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51785 780.382 1358.0 41.3 954329.0 915.5 -1240000
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51785 1380.381 1439.0 56.0 954871.3 915.5 -1240000
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day, second: time of measurement
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elapsed: total time from query to response (microseconds)
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stall: time the server reports that it sat on the request (microseconds)
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skew: difference between local time and server time (microseconds)
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dispersion: reported by server, see RFC-1305 (microseconds)
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freq: local clock frequency adjustment (Linux only, ppm*65536)
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test.dat is suitable for piping into ntpclient -r. I have over 53000
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samples (lines) archived for study, that I don't include here.
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They are spaced 10 minutes apart, representing over a year of data
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logging (not continuous, unfortunately).
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envelope is a perl script that I have used for my lock studies.
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It's kind of a hack and not worth documenting here.
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- Larry Doolittle <larry@doolittle.boa.org>
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