RRDCGI(1)                           rrdtool                          RRDCGI(1)



NAME
       rrdcgi - Create web pages containing RRD graphs based on templates

SYNOPSIS
       "#!/path/to/"rrdcgi [--filter|-f]

DESCRIPTION
       rrdcgi is a sort of very limited script interpreter. Its purpose is to
       run as a cgi-program and parse a web page template containing special
       <RRD:: tags. rrdcgi will interpret and act according to these tags.  In
       the end it will printout a web page including the necessary CGI
       headers.

       rrdcgi parses the contents of the template in 3 steps. In each step it
       looks only for a subset of tags. This allows nesting of tags.

       The argument parser uses the same semantics as you are used from your
       C-shell.

       --filter|-f
               Assume that rrdcgi is run as a filter and not as a cgi.

   Keywords
       RRD::CV name
               Inserts the CGI variable of the given name.

       RRD::CV::QUOTE name
               Inserts the CGI variable of the given name but quotes it, ready
               for use as an argument in another RRD:: tag. So even when there
               are spaces in the value of the CGI variable it will still be
               considered to be one argument.

       RRD::CV::PATH name
               Inserts the CGI variable of the given name, quotes it and makes
               sure it starts neither with a '/' nor contains '..'. This is to
               make sure that no problematic pathnames can be introduced
               through the CGI interface.

       RRD::GETENV variable
               Get the value of an environment variable.

                <RRD::GETENV REMOTE_USER>

               might give you the name of the remote user given you are using
               some sort of access control on the directory.

       RRD::GOODFOR seconds
               Specify the number of seconds this page should remain valid.
               This will prompt the rrdcgi to output a Last-Modified, an
               Expire and if the number of seconds is negative a Refresh
               header.

       RRD::INCLUDE filename
               Include the contents of the specified file into the page
               returned from the cgi.

       RRD::SETENV variable value
               If you want to present your graphs in another time zone than
               your own, you could use

                <RRD::SETENV TZ UTC>

               to make sure everything is presented in Universal Time. Note
               that the values permitted to TZ depend on your OS.

       RRD::SETVAR variable value
               Analog to SETENV but for local variables.

       RRD::GETVAR variable
               Analog to GETENV but for local variables.

       RRD::TIME::LAST rrd-file strftime-format
               This gets replaced by the last modification time of the
               selected RRD. The time is strftime-formatted with the string
               specified in the second argument.

       RRD::TIME::NOW strftime-format
               This gets replaced by the current time of day. The time is
               strftime-formatted with the string specified in the argument.

               Note that if you return : (colons) from your strftime format
               you may have to escape them using \ if the time is to be used
               as an argument to a GRAPH command.

       RRD::TIME::STRFTIME START|END start-spec end-spec strftime-format
               This gets replaced by a strftime-formatted time using the
               format strftime-format on either start-spec or end-spec
               depending on whether START or END is specified.  Both start-
               spec and end-spec must be supplied as either could be relative
               to the other.  This is intended to allow pretty titles on
               graphs with times that are easier for non RRDtool folks to
               figure out than "-2weeks".

               Note that again, if you return : (colon) from your strftime
               format, you may have to escape them using \ if the time is to
               be used as an argument to a GRAPH command.

       RRD::GRAPH rrdgraph arguments
               This tag creates the RRD graph defined by its argument and then
               is replaced by an appropriate <IMG ... > tag referring to the
               graph.  The --lazy option in RRD graph can be used to make sure
               that graphs are only regenerated when they are out of date. The
               arguments to the RRD::GRAPH tag work as described in the
               rrdgraph manual page.

               Use the --lazy option in your RRD::GRAPH tags, to reduce the
               load on your server. This option makes sure that graphs are
               only regenerated when the old ones are out of date.

               If you do not specify your own --imginfo format, the following
               will be used:

                <IMG SRC="%s" WIDTH="%lu" HEIGHT="%lu">

               Note that %s stands for the filename part of the graph
               generated, all directories given in the PNG file argument will
               get dropped.

       RRD::PRINT number
               If the preceding  RRD::GRAPH tag contained any PRINT arguments,
               then you can access their output with this tag. The number
               argument refers to the number of the PRINT argument. The first
               PRINT has number 0.

       RRD::INTERNAL <var>
               This tag gets replaced by an internal var. Currently these vars
               are known: VERSION, COMPILETIME.  These vars represent the
               compiled-in values.

EXAMPLE 1
       The example below creates a web page with a single RRD graph.

        #!/usr/local/bin/rrdcgi
        <HTML>
        <HEAD><TITLE>RRDCGI Demo</TITLE></HEAD>
        <BODY>
        <H1>RRDCGI Example Page</H1>
        <P>
        <RRD::GRAPH demo.png --lazy --title="Temperatures"
                 DEF:cel=demo.rrd:exhaust:AVERAGE
                 LINE2:cel#00a000:"D. Celsius">

        </P>
        </BODY>
        </HTML>

EXAMPLE 2
       This script is slightly more elaborate, it allows you to run it from a
       form which sets RRD_NAME. RRD_NAME is then used to select which RRD you
       want to use as source for your graph.

        #!/usr/local/bin/rrdcgi
        <HTML>
        <HEAD><TITLE>RRDCGI Demo</TITLE></HEAD>
        <BODY>
        <H1>RRDCGI Example Page for <RRD::CV RRD_NAME></H1>
        <H2>Selection</H2>
        <FORM><INPUT NAME=RRD_NAME TYPE=RADIO VALUE=roomA> Room A,
              <INPUT NAME=RRD_NAME TYPE=RADIO VALUE=roomB> Room B.
              <INPUT TYPE=SUBMIT></FORM>
        <H2>Graph</H2>
        <P>
        <RRD::GRAPH <RRD::CV::PATH RRD_NAME>.png --lazy
                 --title "Temperatures for "<RRD::CV::QUOTE RRD_NAME>
                 DEF:cel=<RRD::CV::PATH RRD_NAME>.rrd:exhaust:AVERAGE
                 LINE2:cel#00a000:"D. Celsius">

        </P>
        </BODY>
        </HTML>

EXAMPLE 3
       This example shows how to handle the case where the RRD, graphs and
       cgi-bins are separate directories

        #!/.../bin/rrdcgi
        <HTML>
        <HEAD><TITLE>RRDCGI Demo</TITLE></HEAD>
        <BODY>
        <H1>RRDCGI test Page</H1>
        <RRD::GRAPH
         /.../web/pngs/testhvt.png
         --imginfo '<IMG SRC=/.../pngs/%s WIDTH=%lu HEIGHT=%lu >'
         --lazy --start -1d --end now
         DEF:http_src=/.../rrds/test.rrd:http_src:AVERAGE
         AREA:http_src#00ff00:http_src
        >
        </BODY>
        </HTML>

       Note 1: Replace /.../ with the relevant directories

       Note 2: The SRC=/.../pngs should be paths from the view of the
       webserver/browser

AUTHOR
       Tobias Oetiker <tobi@oetiker.ch>



1.9.0                             2024-07-29                         RRDCGI(1)
