=head1 NAME rrdcgi - Create web pages containing RRD graphs based on templates =head1 SYNOPSIS C<#!/path/to/>B S<[B<--filter>]> =head1 DESCRIPTION B 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 ERRD:: tags. B will interpret and act according to these tags. In the end it will printout a web page including the necessary CGI headers. B 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. =over 8 =item B<--filter> Assume that rrdcgi is run as a filter and not as a cgi. =back =head2 Keywords =over 8 =item RRD::CV I Inserts the CGI variable of the given name. =item RRD::CV::QUOTE I 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. =item RRD::CV::PATH I 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. =item RRD::GETENV I Get the value of an environment variable. might give you the name of the remote user given you are using some sort of access control on the directory. =item RRD::GOODFOR I 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 I a Refresh header. =item RRD::INCLUDE I Include the contents of the specified file into the page returned from the cgi. =item RRD::SETENV I I If you want to present your graphs in another time zone than your own, you could use to make sure everything is presented in Universal Time. Note that the values permitted to TZ depend on your OS. =item RRD::SETVAR I I Analog to SETENV but for local variables. =item RRD::GETVAR I Analog to GETENV but for local variables. =item RRD::TIME::LAST I I This gets replaced by the last modification time of the selected RRD. The time is I-formatted with the string specified in the second argument. =item RRD::TIME::NOW I This gets replaced by the current time of day. The time is I-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. =item RRD::TIME::STRFTIME I I I I This gets replaced by a strftime-formatted time using the format I on either I or I depending on whether I or I is specified. Both I and I 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. =item RRD::GRAPH I This tag creates the RRD graph defined by its argument and then is replaced by an appropriate EIMG ... E tag referring to the graph. The B<--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 B tag work as described in the B manual page. Use the B<--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 B<--imginfo> format, the following will be used: Note that %s stands for the filename part of the graph generated, all directories given in the PNG file argument will get dropped. =item RRD::PRINT I If the preceding B tag contained and B arguments, then you can access their output with this tag. The I argument refers to the number of the B argument. This first B has I 0. =back =head1 EXAMPLE 1 The example below creates a web pages with a single RRD graph. #!/usr/local/bin/rrdcgi RRDCGI Demo

RRDCGI Example Page

=head1 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 RRDCGI Demo

RRDCGI Example Page for

Selection

Room A, Room B.

Graph

.png --lazy --title "Temperatures for " DEF:cel=.rrd:exhaust:AVERAGE LINE2:cel#00a000:"D. Celsius">

=head1 EXAMPLE 3 This example shows how to handle the case where the RRD, graphs and cgi-bins are seperate directories #!/.../bin/rrdcgi RRDCGI Demo

RRDCGI test Page

' --lazy --start -1d --end now DEF:http_src=/.../rrds/test.rrd:http_src:AVERAGE AREA:http_src#00ff00:http_src > Note 1: Replace /.../ with the relevant directories Note 2: The SRC=/.../pngs should be paths from the view of the webserver/browser =head1 AUTHOR Tobias Oetiker Eoetiker@ee.ethz.chE