xttpd(8)xttpd(8)NAMExttpd - Harmonic tide clock and tide predictor (web server)
SYNOPSISxttpd [port] [-cf ``format-string''] [-dc color] [-Dc color] [-df
``format-string''] [-ec color] [-el y|n] [-em pSsMm] [-fc color] [-fg
color] [-ga aspect] [-gh pixels] [-gs d|l|s] [-gt y|n] [-gw pixels]
[-hf ``format-string''] [-in y|n] [-lb y|n] [-lw pixels] [-mc color]
[-Mc color] [-nc color] [-ou y|n] [-pb y|n] [-pi days] [-tf ``format-
string''] [-tl y|n] [-u ft|m] [-v] [-z y|n]
DESCRIPTION
XTide is a package that provides tide and current predictions in a wide
variety of formats. Graphs, text listings, and calendars can be gener‐
ated, or a tide clock can be provided on your desktop.
XTide can work with X-windows, plain text terminals, or the web. This
is accomplished with three separate programs: the interactive interface
(xtide), the non-interactive or command line interface (tide), and the
web interface (xttpd).
xttpd is an XTide web server. It provides web-based access to XTide's
tide predictions by allowing a web browser to speak directly to the
XTide program in HTTP. xttpd can replace httpd or it can co-exist with
one.
If you run xttpd with no command line arguments, it will assume that it
is replacing httpd and try to bind port 80. If you want it to co-exist
with an existing server, or if you do not have privilege to get port
80, give it the port number as the first command line argument:
% xttpd 8080
You will then need to link it up as http://www.wherever.org:8080/
instead of just http://www.wherever.org/, but otherwise, no damage
done. Similarly, if you wish to bind a specific address, you can spec‐
ify that as the first argument:
% xttpd 127.0.0.2
If you need to specify both address and port number, separate the two
with a slash, like this:
% xttpd 127.0.0.2/8080
Once the port is established, xttpd will try to set its UID and GID to
values that were specified at compile time. If it is unable to do
this, it will log failure messages to syslog and then exit. Conse‐
quently, if it is to be started by someone other than root, that user's
UID and GID must be configured at compile time. Instructions for doing
this are available at http://www.flaterco.com/xtide/installation.html.
For a complete discussion of the command line options and a detailed
explanation of the XTide package, please see the verbose documentation
at http://www.flaterco.com/xtide/.
CONFIGURATION
Unless a configuration file /etc/xtide.conf is supplied, you must set
the environment variable HFILE_PATH to point to the harmonics files
that should have been installed along with the xtide program. Example:
export HFILE_PATH=/usr/local/share/xtide/harmonics.tcd
If a configuration file is used, the first line should consist of the
colon-separated list of harmonics files (e.g. the HFILE_PATH line above
without the "export HFILE_PATH=" part). The environment variable takes
precedence over the configuration file.
Set the environment variable XTTPD_FEEDBACK to change the mail feedback
address for xttpd.
OPTIONS-cf ``format-string''
strftime(3) style format string for printing days in calendars
(default %a %d).
-dc color
Daytime background color in tide graphs (default SkyBlue).
-Dc color
Color of datum line in tide graphs (default white).
-df ``format-string''
strftime(3) style format string for printing dates (default
%Y-%m-%d). For calendars see -cf.
-ec color
Foreground in tide graphs during outgoing tide (default Sea‐
Green).
-el y|n
Select whether or not to draw datum and middle-level lines in
tide graphs (default n).
The National Ocean Service (NOS) defines both Mean Sea Level
(MSL) and Mean Tide Level (MTL) in terms of averages taken over
observations. The middle-level line is drawn at the midpoint of
the theoretical tidal range, which usually corresponds to the
mathematical mean level of the predictions. This approximates
both MSL and MTL, but, strictly speaking, is equivalent to nei‐
ther. Moreover, subordinate station offsets may shift the
actual mean so that it no longer falls at the midpoint of the
tidal range. The datum line is drawn at the zero level of the
predictions, which usually corresponds to the station's bench‐
mark, but this too can be rendered inaccurate by subordinate
station offsets.
-em pSsMm
Events to suppress (p = phase of moon, S = sunrise, s = sunset,
M = moonrise, m = moonset), or x to suppress none. E.g, to sup‐
press all sun and moon events, set eventmask to the value pSsMm.
-fc color
Foreground in tide graphs during incoming tide (default Blue).
-fg color
Color of text and other notations (default black).
-ga aspect
Aspect for tide graphs (default 1.0). This controls not the
width or height of the window but rather the relative scaling of
the X and Y axes in the plot of the tide curve.
-gh pixels
Height for tide graphs (default 312 pixels).
-gs d|l|s
Style of graphs and clocks. Valid values: d (default), l
(line), s (semitransparent).
-gt y|n
Select whether or not to label tenths of units in tide graphs
(default n).
-gw pixels
Width for tide graphs (default 960 pixels).
-hf ``format-string''
strftime(3) style format string for printing hour labels on time
axis (default %l).
-in y|n
Select whether or not to use inferred values for some con‐
stituents (default n). For expert use only.
-lb y|n
Select whether or not calendar mode inserts a line break before
prediction values (default n).
-lw pixels
Width of line in graph styles l and s (default 2.5 pixels).
-mc color
Color of mark line in graphs (default red).
-Mc color
Color of middle-level line in tide graphs (default yellow).
-nc color
Nighttime background color in tide graphs (default DeepSkyBlue).
-ou y|n
Select whether or not to print numbers with no ft/m/kt (default
n). Where possible, adds a header line stating the units and
datum.
-pb y|n
Select whether or not calendar mode inserts a page break and
repeats the station header for each month (default y).
-pi days
Number of days of predictions to generate when no end time is
specified (default 4).
-tf ``format-string''
strftime(3) style format string for printing times (default
%l:%M %p %Z).
-tl y|n
Select whether or not to draw depth lines on top of the tide
graph (default n).
-u ft|m
Preferred units of length (default no preference).
-v Print version string and exit.
-z y|n Select whether or not to coerce all time zones to UTC (default
n).
SEE ALSOtide(1), xtide(1), http://www.flaterco.com/xtide/.
XTide 2 2014-06-20 xttpd(8)
