.TH xttpd 8 "2008-01-18"  "XTide 2"
.SH NAME
xttpd \- Harmonic tide clock and tide predictor (web server)
.SH SYNOPSIS
.B xttpd
[\fBport\fP]
[\fB-dc color\fP]
[\fB-Dc color\fP]
[\fB-df ``format-string''\fP]
[\fB-ec color\fP]
[\fB-el y|n\fP]
[\fB-em pSsMm\fP]
[\fB-fc color\fP]
[\fB-fg color\fP]
[\fB-ga aspect\fP]
[\fB-gh pixels\fP]
[\fB-gt y|n\fP]
[\fB-gw pixels\fP]
[\fB-hf ``format-string''\fP]
[\fB-in y|n\fP]
[\fB-lw pixels\fP]
[\fB-mc color\fP]
[\fB-Mc color\fP]
[\fB-nc color\fP]
[\fB-nf y|n\fP]
[\fB-tf ``format-string''\fP]
[\fB-tl y|n\fP]
[\fB-u ft|m\fP]
[\fB-v\fP]
[\fB-z y|n\fP]
.SH DESCRIPTION
XTide is a package that provides tide and current predictions in a wide
variety of formats. Graphs, text listings, and calendars can be generated,
or a tide clock can be provided on your desktop.
.LP
XTide can work with X-windows, plain text terminals, or the web. This is
accomplished with three separate programs: the interactive interface
(\fBxtide\fP), the non-interactive or command line interface
(\fBtide\fP), and the web interface (\fBxttpd\fP).
.LP
.B 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.
.B xttpd
can replace
.B httpd
or it can co-exist with one.
.LP
If you run
.B xttpd
with no command line arguments, it will assume that it is
replacing
.B 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:
.RS
% xttpd 8080
.RE
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
specify that as the first argument:
.RS
% xttpd 127.0.0.2
.RE
If you need to specify both address and port number, separate the two
with a slash, like this:
.RS
% xttpd 127.0.0.2/8080
.RE
.LP
Once the port is established,
.B 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.  Consequently, 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
.BR http://www.flaterco.com/xtide/installation.html .
.LP
For a complete
discussion of the command line options and a detailed explanation of the
XTide package, please see the verbose documentation at
.BR http://www.flaterco.com/xtide/ .
.SH CONFIGURATION
Unless a configuration file
.B /etc/xtide.conf
is supplied, you must set the environment variable
.B HFILE_PATH
to point to the harmonics
files that should have been installed along with the
.B xtide
program.  Example:
.RS
export HFILE_PATH=/usr/local/share/xtide/harmonics.tcd
.RE
If a configuration file is used, the first line should consist of the
colon-separated list of harmonics files (e.g. the
.B HFILE_PATH
line above without the "export HFILE_PATH=" part).
The environment variable takes precedence over the configuration file.
.SH CONFIGURATION ON DEBIAN SYSTEMS
On
.B Debian 
systems the web server 
.B xttpd
may optionally be started at boot time by editing
.I /etc/init.d/xttpd 
(setting the 
.B PORT 
variable and uncommenting out the line). Set the environment variable
.B XTTPD_FEEDBACK 
in 
.I /etc/init.d/xttpd 
to change the mail feedback address.
.LP
Also, note that on Debian systems the tidal harmonics data file are stored in
.I /usr/share/xtide
instead of
.I /usr/local/share/xtide
as used above.
.SH OPTIONS
.TP
.B -dc color
Daytime background color in tide graphs (default SkyBlue).
.TP
.B -Dc color
Color of datum line in tide graphs (default white).
.TP
.B -df ``format-string''
.BR strftime (3)
style format string for printing dates (default %Y-%m-%d).
.TP
.B -ec color
Foreground in tide graphs during outgoing tide (default SeaGreen).
.TP
.B -el y|n
Select whether or not to draw datum and middle-level lines in tide graphs
(default n).
.TP
.B -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 suppress all sun and moon events,
set eventmask to the value pSsMm.
.TP
.B -fc color
Foreground in tide graphs during incoming tide (default Blue).
.TP
.B -fg color
Color of text and other notations (default black).
.TP
.B -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.
.TP
.B -gh pixels
Height for tide graphs (default 312 pixels).
.TP
.B -gt y|n
Select whether or not to label tenths of units in tide graphs
(default n).
.TP
.B -gw pixels
Width for tide graphs (default 960 pixels).
.TP
.B -hf ``format-string''
.BR strftime (3)
style format string for printing hour labels on time axis (default %l).
.TP
.B -in y|n
Select whether or not to use inferred values for some constituents (default n).
For expert use only.
.TP
.B -lw pixels
Width for lines in tide graphs with
.B -nf
(default 2.5 pixels).
.TP
.B -mc color
Color of mark line in graphs (default red).
.TP
.B -Mc color
Color of middle-level line in tide graphs (default yellow).
.TP
.B -nc color
Nighttime background color in tide graphs (default DeepSkyBlue).
.TP
.B -nf y|n
Select whether or not to draw tide graphs as line graphs
(default n).
.TP
.B -tf ``format-string''
.BR strftime (3)
style format string for printing times (default %l:%M %p %Z).
.TP
.B -tl y|n
Select whether or not to draw depth lines on top of the tide graph
(default n).
.TP
.B -u ft|m
Preferred units of length (default no preference).
.TP
.B -v
Print version string and exit.
.TP
.B -z y|n
Select whether or not to coerce all time zones to UTC (default n).
.SH "SEE ALSO"
.BR tide (1),
.BR xtide (1),
.BR http://www.flaterco.com/xtide/ .
.sp