1: .TH SNTP 1 2011-12-24 "( 4.2.6p5)" "Programmer's Manual"
2: .\" EDIT THIS FILE WITH CAUTION (sntp.1)
3: .\"
4: .\" It has been AutoGen-ed December 24, 2011 at 06:33:59 PM by AutoGen 5.12
5: .\" From the definitions sntp-opts.def
6: .\" and the template file agman1.tpl
7: .\"
8: .SH NAME
9: sntp \- standard Simple Network Time Protocol program
10: .SH SYNOPSIS
11: .B sntp
12: .\" Mixture of short (flag) options and long options
13: .RB [ \-\fIflag\fP " [\fIvalue\fP]]... [" \--\fIopt-name\fP " [[=| ]\fIvalue\fP]]..."
14: .br
15: .in +8
16: [ hostname-or-IP ...]
17: .PP
18:
19: .SH "DESCRIPTION"
20: This manual page briefly documents the \fBsntp\fP command.
21: .I sntp
22: can be used as a SNTP client to query a NTP or SNTP server and either display
23: the time or set the local system's time (given suitable privilege). It can be
24: run as an interactive command or in a
25: .I cron
26: job.
27:
28: NTP (the Network Time Protocol) and SNTP (the Simple Network Time Protocol)
29: are defined and described by RFC 5905.
30:
31: .PP
32: The default is to write the estimated correct local date and time (i.e. not
33: UTC) to the standard output in a format like
34: .BR "'1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 secs'" ,
35: where the
36: .B "'(+0800)'"
37: means that to get to UTC from the reported local time one must
38: add 8 hours and 0 minutes,
39: and the
40: .B "'+4.567 +/- 0.089 secs'"
41: indicates the local clock is 4.567 seconds behind the correct time
42: (so 4.567 seconds must be added to the local clock to get it to be correct),
43: and the time of
44: '1996-10-15 20:17:25.123'
45: is believed to be correct to within
46: +/- 0.089
47: seconds.
48: .SH OPTIONS
49: .TP
50: .BR \-4 ", " \--ipv4
51: Force IPv4 DNS name resolution.
52: This option must not appear in combination with any of the following options:
53: ipv6.
54: .sp
55: Force DNS resolution of the following host names on the command line
56: to the IPv4 namespace.
57: .TP
58: .BR \-6 ", " \--ipv6
59: Force IPv6 DNS name resolution.
60: This option must not appear in combination with any of the following options:
61: ipv4.
62: .sp
63: Force DNS resolution of the following host names on the command line
64: to the IPv6 namespace.
65: .TP
66: .BR \-d ", " \--normalverbose
67: Normal verbose.
68: .sp
69: Diagnostic messages for non-fatal errors and a limited amount of
70: tracing should be written to standard error. Fatal ones always
71: produce a diagnostic. This option should be set when there is a
72: suspected problem with the server, network or the source.
73: .TP
74: .BR \-K " \fIfile-name\fP, " \--kod "=" \fIfile-name\fP
75: KoD history filename.
76: .sp
77: Specifies the filename to be used to persist the history of KoD
78: responses received from servers. The default is
79: /var/db/ntp-kod.
80: .TP
81: .BR \-p ", " \--syslog
82: Logging with syslog.
83: This option must not appear in combination with any of the following options:
84: logfile.
85: .sp
86: When this option is set all logging will be done using syslog.
87: .TP
88: .BR \-l " \fIfile-name\fP, " \--logfile "=" \fIfile-name\fP
89: Log to specified logfile.
90: This option must not appear in combination with any of the following options:
91: syslog.
92: .sp
93: This option causes the client to write log messages to the specified
94: logfile.
95: .TP
96: .BR \-s ", " \--settod
97: Set (step) the time with settimeofday().
98: This option must not appear in combination with any of the following options:
99: adjtime.
100: .sp
101:
102: .TP
103: .BR \-j ", " \--adjtime
104: Set (slew) the time with adjtime().
105: This option must not appear in combination with any of the following options:
106: settod.
107: .sp
108:
109: .TP
110: .BR \-b " \fIbroadcast-address\fP, " \--broadcast "=" \fIbroadcast-address\fP
111: Use broadcasts to the address specified for synchronisation.
112: .sp
113: If specified SNTP will listen to the specified broadcast address
114: for NTP broadcasts. The default maximum wait time,
115: 68 seconds, can be modified with \-t.
116: .TP
117: .BR \-t " \fIseconds\fP, " \--timeout "=" \fIseconds\fP
118: Specify the number of seconds to wait for broadcasts.
119: This option takes an integer number as its argument.
120: The default \fIseconds\fP for this option is:
121: .ti +4
122: 68
123: .sp
124: When waiting for a broadcast packet SNTP will wait the number
125: of seconds specified before giving up. Default 68 seconds.
126: .TP
127: .BR \-a " \fIauth-keynumber\fP, " \--authentication "=" \fIauth-keynumber\fP
128: Enable authentication with the key auth-keynumber.
129: This option takes an integer number as its argument.
130: .sp
131: This option enables authentication using the key specified in this option's argument.
132: The argument of this option is the keyid, a number specified in the keyfile as this
133: key's identifier. See the keyfile option (-k) for more details.
134: .TP
135: .BR \-k " \fIfile-name\fP, " \--keyfile "=" \fIfile-name\fP
136: Specify a keyfile. SNTP will look in this file for the key specified with \-a.
137: .sp
138: This option specifies the keyfile. SNTP will search for the key specified with \-a keyno in this
139: file. Key files follow the following format:
140:
141: keyid keytype key
142:
143: Where keyid is a number identifying this key
144: keytype is one of the follow:
145: S Key in 64 Bit hexadecimal number as specified in in the DES specification.
146: N Key in 64 Bit hexadecimal number as specified in the NTP standard.
147: A Key in a 1-to-8 character ASCII string.
148: M Key in a 1-to-8 character ASCII string using the MD5 authentication scheme.
149:
150: For more information see ntp.keys(5).
151: .TP
152: .BR \-? , " \--help"
153: Display extended usage information and exit.
154: .TP
155: .BR \-! , " \--more-help"
156: Extended usage information passed thru pager.
157: .TP
158: .BR \-> " [\fIrcfile\fP]," " \--save-opts" "[=\fIrcfile\fP]"
159: Save the option state to \fIrcfile\fP. The default is the \fIlast\fP
160: configuration file listed in the \fBOPTION PRESETS\fP section, below.
161: .TP
162: .BR \-< " \fIrcfile\fP," " \--load-opts" "=\fIrcfile\fP," " \--no-load-opts"
163: Load options from \fIrcfile\fP.
164: The \fIno-load-opts\fP form will disable the loading
165: of earlier RC/INI files. \fI--no-load-opts\fP is handled early,
166: out of order.
167: .TP
168: .BR \- " [{\fIv|c|n\fP}]," " \--version" "[=\fI{v|c|n}\fP]"
169: Output version of program and exit. The default mode is `v', a simple
170: version. The `c' mode will print copyright information and `n' will
171: print the full copyright notice.
172: .SH OPTION PRESETS
173: Any option that is not marked as \fInot presettable\fP may be preset
174: by loading values from configuration ("RC" or ".INI") file(s) and values from
175: environment variables named:
176: .nf
177: \fBSNTP_<option-name>\fP or \fBSNTP\fP
178: .fi
179: .ad
180: The environmental presets take precedence (are processed later than)
181: the configuration files.
182: The \fIhomerc\fP files are "\fI$HOME\fP", and "\fI.\fP".
183: If any of these are directories, then the file \fI.ntprc\fP
184: is searched for within those directories.
185: .SH USAGE
186: The simplest use of this program is as an unprivileged command to check the
187: current time and error in the local clock. For example:
188: .IP
189: .B sntp ntpserver.somewhere
190: .PP
191: With suitable privilege, it can be run as a command or in a
192: .I cron
193: job to reset the local clock from a reliable server, like the
194: .I ntpdate
195: and
196: .I rdate
197: commands. For example:
198: .IP
199: .B sntp \-a ntpserver.somewhere
200: .SH RETURN VALUE
201: The program returns a zero exit
202: status for success, and a non-zero one otherwise.
203: .SH BUGS
204: Please report bugs to http://bugs.ntp.org .
205: .SH AUTHOR
206: David L. Mills and/or others
207: .br
208: Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org
209:
210: .PP
211: .nf
212: .na
213: see html/copyright.html
214:
215: .fi
216: .ad
217: .PP
218: This manual page was \fIAutoGen\fP-erated from the \fBsntp\fP
219: option definitions.
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