Provided by: xtide_2.13.2-1build1_amd64 bug


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


       xttpd  [port]  [-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] [-lw pixels] [-mc color] [-Mc color] [-nc color]
       [-pi days] [-tf ``format-string''] [-tl y|n] [-u ft|m] [-v] [-z y|n]


       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.

       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
              % xttpd 8080
       You  will  then  need  to  link  it  up  as instead of just, but otherwise, no damage done.  Similarly, if you wish to bind a
       specific address, you can specify that as the first argument:
              % xttpd
       If  you  need to specify both address and port number, separate the two with a slash, like
              % xttpd

       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.  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

       For a complete discussion of the command line options and a detailed  explanation  of  the
       XTide package, please see the verbose documentation at


       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.


       On  Debian  systems the web server xttpd may optionally be started at boot time by editing
       /etc/init.d/xttpd (setting the PORT variable and  uncommenting  out  the  line).  Set  the
       environment  variable  XTTPD_FEEDBACK  in  /etc/init.d/xttpd  to  change the mail feedback

       Also,  note  that  on  Debian  systems  the  tidal  harmonics  data  file  are  stored  in
       /usr/share/xtide instead of /usr/local/share/xtide as used above.


       -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).  Ignored in
              calendar mode.

       -ec color
              Foreground in tide graphs during outgoing tide (default SeaGreen).

       -el y|n
              Select whether or not to draw datum and middle-level lines in tide graphs  (default

              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 neither.  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 benchmark, 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 suppress 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

       -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

       -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  constituents  (default  n).
              For expert use only.

       -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).

       -pi days
              Number  of  days  of predictions to generate when no end time is specified (default

       -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).


       tide(1), xtide(1),