'\" t
.\"     Title: gpslogntp
.\"    Author: Gary E. Miller
.\" Generator: Asciidoctor 2.0.23
.\"      Date: 2025-05-06
.\"    Manual: GPSD Documentation
.\"    Source: GPSD, Version 3.26
.\"  Language: English
.\"
.TH "GPSLOGNTP" "1" "2025-05-06" "GPSD, Version 3.26" "GPSD Documentation"
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.ss \n[.ss] 0
.nh
.ad l
.de URL
\fI\\$2\fP <\\$1>\\$3
..
.als MTO URL
.if \n[.g] \{\
.  mso www.tmac
.  am URL
.    ad l
.  .
.  am MTO
.    ad l
.  .
.  LINKSTYLE blue R < >
.\}
.SH "NAME"
gpslogntp \- log gpsd data for ntpviz
.SH "SYNOPSIS"
.sp
.nf
gpslogntp [\-h] [\-l LOGFILE] [\-o] [\-w WAIT] [\-v] [\-V]
.fi
.br
.sp
.if n .RS 4
.nf
.fam C
\-h, \-\-help\&            show this help message and exit
\-l LOGFILE, \-\-logfile LOGFILE
                      append log data to LOGFILE instead of stdout
\-o, \-\-once\&            log one line, then exit
\-w WAIT, \-\-wait WAIT\&  wait WAIT seconds between log lines, default 5
\-v, \-\-verbose\&         be verbose
\-V, \-\-version\&         show program\*(Aqs version number and exit
.fam
.fi
.if n .RE
.SH "DESCRIPTION"
.sp
gpslogntp connects to a local gpsd daemon and logs the number of satellites
in use and the Time Dilution of Precision (TDOP).  gpslogntp can run as
any user, no special privileges are required.  This log is intended to
be used by \fBntpviz\fP.
.sp
The default is to write the data to stdout about once every 5 seconds.
The log file looks like:
.sp
.if n .RS 4
.nf
.fam C
# Time\&       Device\&     TDOP\&     nSat
1483668619.0 /dev/ttyS0 0.820000 7
1483668624.0 /dev/ttyS0 0.820000 7
1483668629.0 /dev/ttyS0 0.820000 7
.fam
.fi
.if n .RE
.sp
Time is the POSIX time of when the log line is written.
.sp
Device is the GPS device the data came from.
.sp
TDOP is the Time Dilution of Precision as reported by the GPS.  Some
GPS always output a static TDOP.
.sp
nSat is the number of satellites in use.
.sp
Formerly known as \fBntploggps\fP and formerly part of NTPsec.
.sp
Note: Many GNSS receivers always report TDOP as "1.0".
.SH "OPTIONS"
.sp
\-h, \-\-help
.RS 4
Displays usage information and exits.
.RE
.sp
\-l LOGFILE, \-\-logfile LOGFILE
.RS 4
Append log data to LOGFILE instead of stdout
.RE
.sp
\-o, \-\-once
.RS 4
Log one line, then exit.
.RE
.sp
\-v, \-\-verbose
.RS 4
Be verbose
.RE
.sp
\-w WAIT, \-\-wait WAIT
.RS 4
Wait WAIT seconds after each log line.  The default is 5 seconds.  This
is just the minimum wait time.  gpsd may be reporting data at a much
slower interval.
.RE
.sp
\-V, \-\-version
.RS 4
show program\(cqs version number and exit
.RE
.SH "USAGE"
.sp
gpslogntp
.RS 4
This the simplest use of this program. It can be used to check the
status of the local gpsd daemon.
.RE
.sp
gpslogntp \-l /var/log/ntpstats/gpsd \-w 60 &
.RS 4
This will continuously log the gpsd data in the background to the file
/var/log/ntpstats/gpsd.  Only log every 60 seconds.
.RE
.SH "AUTHORS"
.sp
Gary E. Miller
.SH "EXIT STATUS"
.sp
One of the following exit values will be returned:
.sp
0 (EXIT_SUCCESS)
.RS 4
Successful program execution.
.RE
.sp
1 (EXIT_FAILURE)
.RS 4
The operation failed or the command syntax was not valid.
.RE
.SH "SEE ALSO"
.sp
\fBgpsd\fP(8), \fBgps\fP(1), \fBntpviz\fP(1), \fBntpd\fP(8).
.SH "RESOURCES"
.sp
\fBProject web site:\fP \c
.URL "https://gpsd.io/" "" ""
.SH "COPYING"
.sp
This file is Copyright by the GPSD project
.br
This file is Copyright by the NTPSec project
.br
SPDX\-License\-Identifier: BSD\-2\-clause
.SH "AUTHOR"
.sp
Gary E. Miller