1xttpd(8)                    System Manager's Manual                   xttpd(8)
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NAME

6       xttpd - Harmonic tide clock and tide predictor (web server)
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SYNOPSIS

9       xttpd  [port]  [-cf  ``format-string'']  [-dc  color]  [-Dc color] [-df
10       ``format-string''] [-ec color] [-el y|n] [-em pSsMm] [-fc  color]  [-fg
11       color]  [-ga  aspect]  [-gh  pixels] [-gs d|l|s] [-gt y|n] [-gw pixels]
12       [-hf ``format-string''] [-in y|n] [-lb y|n] [-lw  pixels]  [-mc  color]
13       [-Mc  color]  [-nc color] [-ou y|n] [-pb y|n] [-pi days] [-tf ``format-
14       string''] [-tl y|n] [-u ft|m] [-v] [-z y|n]
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DESCRIPTION

17       XTide is a package that provides tide and current predictions in a wide
18       variety  of formats. Graphs, text listings, and calendars can be gener‐
19       ated, or a tide clock can be provided on your desktop.
20
21       XTide can work with X-windows, plain text terminals, or the  web.  This
22       is accomplished with three separate programs: the interactive interface
23       (xtide), the non-interactive or command line interface (tide), and  the
24       web interface (xttpd).
25
26       xttpd  is  an XTide web server. It provides web-based access to XTide's
27       tide predictions by allowing a web browser to  speak  directly  to  the
28       XTide program in HTTP.  xttpd can replace httpd or it can co-exist with
29       one.
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31       At installation time, xttpd can be configured to integrate with systemd
32       or it can be used in conventional init mode.
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34       In  conventional mode, if you run xttpd with no command line arguments,
35       it will assume that it is replacing httpd and try to bind port  80.  If
36       you  want it to co-exist with an existing server, or if you do not have
37       privilege to get port 80, give it the port number as the first  command
38       line argument:
39              % xttpd 8080
40       You  will  then  need  to  link  it up as http://www.wherever.org:8080/
41       instead of just  http://www.wherever.org/,  but  otherwise,  no  damage
42       done.  Similarly, if you wish to bind a specific address, you can spec‐
43       ify that as the first argument:
44              % xttpd 127.0.0.2
45       If you need to specify both address and port number, separate  the  two
46       with a slash, like this:
47              % xttpd 127.0.0.2/8080
48       IPv6 addresses and hostnames are also accepted for the address.
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50       When  systemd  is used, the port and address must instead be configured
51       in systemd configuration files.
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53       Once the port is established, xttpd will try to set its UID and GID  to
54       values  that  were  specified  at  compile time.  If it is unable to do
55       this, it will log failure messages to syslog  and  then  exit.   Conse‐
56       quently, if it is to be started by someone other than root, that user's
57       UID and GID must be configured at compile time.  Instructions for doing
58       this are available at https://flaterco.com/xtide/installation.html.
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60       For  a  complete  discussion of the command line options and a detailed
61       explanation of the XTide package, please see the verbose  documentation
62       at https://flaterco.com/xtide/.
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CONFIGURATION

65       Unless  a  configuration file /etc/xtide.conf is supplied, you must set
66       the environment variable HFILE_PATH to point  to  the  harmonics  files
67       that should have been installed along with the xtide program.  Example:
68              export HFILE_PATH=/usr/local/share/xtide/harmonics.tcd
69       If  a  configuration file is used, the first line should consist of the
70       colon-separated list of harmonics files (e.g. the HFILE_PATH line above
71       without the "export HFILE_PATH=" part).  The environment variable takes
72       precedence over the configuration file.
73
74       Set the environment variable XTTPD_FEEDBACK to change the mail feedback
75       address for xttpd.
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OPTIONS

78       -cf ``format-string''
79              strftime(3)  style  format string for printing days in calendars
80              (default %a %d).
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82       -dc color
83              Daytime background color in tide graphs (default SkyBlue).
84
85       -Dc color
86              Color of datum line in tide graphs (default white).
87
88       -df ``format-string''
89              strftime(3) style format  string  for  printing  dates  (default
90              %Y-%m-%d).  For calendars see -cf.
91
92       -ec color
93              Foreground  in  tide  graphs  during outgoing tide (default Sea‐
94              Green).
95
96       -el y|n
97              Select whether or not to draw datum and  middle-level  lines  in
98              tide graphs (default n).
99
100              The  National  Ocean  Service  (NOS) defines both Mean Sea Level
101              (MSL) and Mean Tide Level (MTL) in terms of averages taken  over
102              observations.  The middle-level line is drawn at the midpoint of
103              the theoretical tidal range, which usually  corresponds  to  the
104              mathematical  mean  level of the predictions.  This approximates
105              both MSL and MTL, but, strictly speaking, is equivalent to  nei‐
106              ther.   Moreover,  subordinate  station  offsets  may  shift the
107              actual mean so that it no longer falls at the  midpoint  of  the
108              tidal  range.   The datum line is drawn at the zero level of the
109              predictions, which usually corresponds to the  station's  bench‐
110              mark,  but  this  too  can be rendered inaccurate by subordinate
111              station offsets.
112
113       -em pSsMm
114              Events to suppress (p = phase of moon, S = sunrise, s =  sunset,
115              M = moonrise, m = moonset), or x to suppress none.  E.g, to sup‐
116              press all sun and moon events, set eventmask to the value pSsMm.
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118       -fc color
119              Foreground in tide graphs during incoming tide (default Blue).
120
121       -fg color
122              Color of text and other notations (default black).
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124       -ga aspect
125              Aspect for tide graphs (default 1.0).   This  controls  not  the
126              width or height of the window but rather the relative scaling of
127              the X and Y axes in the plot of the tide curve.
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129       -gh pixels
130              Height for tide graphs (default 312 pixels).
131
132       -gs d|l|s
133              Style of graphs  and  clocks.   Valid  values:  d  (default),  l
134              (line), s (semitransparent).
135
136       -gt y|n
137              Select  whether  or  not to label tenths of units in tide graphs
138              (default n).
139
140       -gw pixels
141              Width for tide graphs (default 960 pixels).
142
143       -hf ``format-string''
144              strftime(3) style format string for printing hour labels on time
145              axis (default %l).
146
147       -in y|n
148              Select  whether  or  not  to  use  inferred values for some con‐
149              stituents (default n).  For expert use only.
150
151       -lb y|n
152              Select whether or not calendar mode inserts a line break  before
153              prediction values (default n).
154
155       -lw pixels
156              Width of line in graph styles l and s (default 2.5 pixels).
157
158       -mc color
159              Color of mark line in graphs (default red).
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161       -Mc color
162              Color of middle-level line in tide graphs (default yellow).
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164       -nc color
165              Nighttime background color in tide graphs (default DeepSkyBlue).
166
167       -ou y|n
168              Select  whether or not to print numbers with no ft/m/kt (default
169              n). Where possible, adds a header line  stating  the  units  and
170              datum.
171
172       -pb y|n
173              Select  whether  or  not  calendar mode inserts a page break and
174              repeats the station header for each month (default y).
175
176       -pi days
177              Number of days of predictions to generate when no  end  time  is
178              specified (default 4).
179
180       -tf ``format-string''
181              strftime(3)  style  format  string  for  printing times (default
182              %l:%M %p %Z).
183
184       -tl y|n
185              Select whether or not to draw depth lines on  top  of  the  tide
186              graph (default n).
187
188       -u ft|m
189              Preferred units of length (default no preference).
190
191       -v     Print version string and exit.
192
193       -z y|n Select  whether  or not to coerce all time zones to UTC (default
194              n).
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SEE ALSO

197       tide(1), xtide(1), https://flaterco.com/xtide/.
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202XTide 2                           2020-06-27                          xttpd(8)
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