1xttpd(8) System Manager's Manual xttpd(8)
2
6 xttpd - Harmonic tide clock and tide predictor (web server)
7
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]
15
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 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 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.
30 At installation time, xttpd can be configured to integrate with systemd
32 or it can be used in conventional init mode.
33 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.
49 When systemd is used, the port and address must instead be configured
51 in systemd configuration files.
52 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.
59 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/.
63
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 Set the environment variable XTTPD_FEEDBACK to change the mail feedback
75 address for xttpd.
76
78 -cf ``format-string''
79 strftime(3) style format string for printing days in calendars
80 (default %a %d).
81 -dc color
83 Daytime background color in tide graphs (default SkyBlue).
84 -Dc color
86 Color of datum line in tide graphs (default white).
87 -df ``format-string''
89 strftime(3) style format string for printing dates (default
90 %Y-%m-%d). For calendars see -cf.
91 -ec color
93 Foreground in tide graphs during outgoing tide (default Sea‐
94 Green).
95 -el y|n
97 Select whether or not to draw datum and middle-level lines in
98 tide graphs (default n).
99 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 -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.
117 -fc color
119 Foreground in tide graphs during incoming tide (default Blue).
120 -fg color
122 Color of text and other notations (default black).
123 -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.
128 -gh pixels
130 Height for tide graphs (default 312 pixels).
131 -gs d|l|s
133 Style of graphs and clocks. Valid values: d (default), l
134 (line), s (semitransparent).
135 -gt y|n
137 Select whether or not to label tenths of units in tide graphs
138 (default n).
139 -gw pixels
141 Width for tide graphs (default 960 pixels).
142 -hf ``format-string''
144 strftime(3) style format string for printing hour labels on time
145 axis (default %l).
146 -in y|n
148 Select whether or not to use inferred values for some con‐
149 stituents (default n). For expert use only.
150 -lb y|n
152 Select whether or not calendar mode inserts a line break before
153 prediction values (default n).
154 -lw pixels
156 Width of line in graph styles l and s (default 2.5 pixels).
157 -mc color
159 Color of mark line in graphs (default red).
160 -Mc color
162 Color of middle-level line in tide graphs (default yellow).
163 -nc color
165 Nighttime background color in tide graphs (default DeepSkyBlue).
166 -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 -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 -pi days
177 Number of days of predictions to generate when no end time is
178 specified (default 4).
179 -tf ``format-string''
181 strftime(3) style format string for printing times (default
182 %l:%M %p %Z).
183 -tl y|n
185 Select whether or not to draw depth lines on top of the tide
186 graph (default n).
187 -u ft|m
189 Preferred units of length (default no preference).
190 -v Print version string and exit.
192 -z y|n Select whether or not to coerce all time zones to UTC (default
194 n).
195
197 tide(1), xtide(1), https://flaterco.com/xtide/.
198XTide 2 2020-06-27 xttpd(8)