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>

1.10.3                            2026-05-25                         RRDCGI(1)
