=head1 NAME  

rrdgraph_graph - Command reference

=head1 SYNOPSIS

B<PRINT>B<:>I<vname>B<:>I<format>

B<GPRINT>B<:>I<vname>B<:>I<format>

B<COMMENT>B<:>I<text>

B<VRULE>B<:>I<vname>B<#>I<color>[B<:>I<legend>]

B<LINE>I<width>B<:>I<vname>B<#>I<color>[B<:>I<legend>][B<:>B<STACK>]

B<AREA>B<:>I<vname>B<#>I<color>[B<:>I<legend>][B<:>B<STACK>]

B<TICK>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<fraction>[B<:>I<legend>]]

B<SHIFT>B<:>I<vname>B<:>I<offset>

=cut

B<PART>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<legend>]

=pod

B<PRINT>B<:>I<vname>B<:>I<CF>B<:>I<format> (deprecated)

B<GPRINT>B<:>I<vname>B<:>I<CF>B<:>I<format> (deprecated)

B<HRULE>B<:>I<value>B<#>I<color>[B<:>I<legend>] (deprecated)

B<STACK>B<:>I<vname>B<#>I<color>[B<:>I<legend>] (deprecated)

=head1 DESCRIPTION

These instructions allow you to generate your image or report.
If you don't use any graph elements, no graph is generated.
Similarly no report is generated if you don't use print options.

=head1 PRINT

=over 4

=item B<PRINT:>I<vname>B<:>I<CF><:>I<format>

I<Deprecated. Use the new form of this command in new scripts.>
The first form of this command is to be used with B<CDEF> I<vname>s.

=item B<PRINT:>I<vname>B<:>I<format>

Depending on the context, either the value component or the time
component of a B<VDEF> is printed using I<format>. It is an error
to specify a I<vname> generated by a B<DEF> or B<CDEF>.

Any text in I<format> is printed literally with one exception:
The percent character introduces a formatter string. This string
can be:

For printing values:

=over 4

=item *

B<%%> just prints a literal '%' character

=item *

B<%#.#le> prints like 1.2346e+04. Optional numbers # are field width and
decimal precision

=item *

B<%#.#lf> prints like 12345.6789, with optional field width and precision

=item *

B<%s> place this after B<%le>, B<%lf> or B<%lg>. This will be replaced by the
appropriate SI magnitude unit and the value will be scaled
accordingly (123456 -> 123.456 k)

=item *

B<%S> is similar to B<%s>. It does however use a previously defined
magnitude unit. If there is no such unit yet, it tries to define
one (just like B<%s>). However, if the value is zero, the magnitude
unit stays undefined. Thus, formatter strings using B<%S> and no B<%s>
will all use the same magnitude unit except for zero values.

=back

For printing times:

=over 4

=item *

B<%%> just prints a literal '%' character

=item *

B<%a, %A> prints abbreviated, full weekday name

=item *

B<%b, %B> prints abbreviated, full month name

=item *

B<%d, %m, %y, %H, %M, %S> day,month,year,hour,minute,second all in two-digit format

=item *

B<%Y> year in 4-digit format

=item *

B<%I, %p>  hour (01..12), 'am' or 'pm'

=item *

B<%j, %w> day of the week (0..6), day of the year (1..366)

=item *

B<%c, %x, %X> date+time, date, time

=item *

B<%U, %W> week number of the current year with either the first Sunday or
the first Monday determining the first week

=item *

B<%Z> time zone

=back

=back

=head1 GRAPH

=over 4

=item B<GPRINT>B<:>I<vname>B<:>I<CF>B<:>I<format>

I<Deprecated. Use the new form of this command in new scripts.>
This is the same as C<PRINT> but now it is printed inside the graph.

=item B<GPRINT>B<:>I<vname>B<:>I<format>

This is the same as C<PRINT> but now it is printed inside the graph.

=item B<COMMENT>B<:>I<text>

Text is printed literally in the legend section of the graph

=item B<HRULE>B<:>I<value>B<#>I<color> [ :I<legend> ]

I<Deprecated. Use B<LINEx> in new scripts.>

=item B<VRULE>B<:>I<vname>B<#>I<color> [B<:>I<legend> ]

Draw a vertical line at I<time>.  Its color is composed from three
hexadecimal numbers specifying the color components (00 is off, FF is
maximum) red, green and blue.  Optionally a legend box and string is
printed in the legend section. I<time> may be a number or a variable
from a B<VDEF>. It is an error to use I<vname>s from B<DEF> or B<CDEF> here.

=item B<LINE>I<width>B<:>I<{vname or number}>B<#>I<color>[B<:>I<legend>]
[ C<:STACK> ]

Draw a line of the specified width into the graph. If the color
is not specified, the drawing is done 'blind'.  This is useful when
stacking something else on top of this line. Also optional is the
legend box and string which will be printed in the legend section
if specified. The B<vname> can be generated by B<DEF>, B<VDEF> and
B<CDEF>.  If the optional B<STACK> modifier is used, this line is
stacked on top of the previous element which can be a B<LINEx> or
an B<AREA>

=item B<AREA>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<legend>][B<:STACK>]

See B<LINE>, however the area between the x-axis and the line will
also be filled.

=item B<TICK>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<fraction>[B<:>I<legend>]]

Plot a tick mark (a vertical line) for each value of I<vname> that is
non-zero and not *UNKNOWN*. The I<fraction> argument specifies the
length of the tick mark as a fraction of the y-axis; the default value
is 0.1 (10% of the axis). Note that the color specification is not
optional.

=item B<SHIFT>B<:>I<vname>B<:>I<offset>

Using this command B<RRDtool> will graph the following elements
with the specified offset.  For instance, you can specify an
offset of S<( 7*24*60*60 = ) 604800 seconds> to "look back" one
week. Make sure to notify the viewer you did so...
As with the other graphing elements, you can specify a number or
a variable here.

=cut

=item B<PART>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<legend>]

B<RRDtool> has now support for B<pie charts>. If you include the
B<PART> command, the canvas is extended to make room for a chart
The size of the canvas is determined by the lesser of
L<width and height|rrdgraph/item_Size>.

Pie parts will be concatenated, the first one will start at the
top and parts will be created clockwise.  The size of the part
is defined by the value part of the L<VDEF|rrdgraph_data/VDEF>
function.  It should return a number between 0 and 100, being a
percentage.  Providing wrong input will produce undefined results.

=pod

=item B<STACK>B<:>I<vname>B<#>I<color>[B<:>I<legend>]

I<Deprecated.  Use the B<STACK> modifiers on the other commands.>

=back

B<Some notes on stacking>

When stacking, an element is not placed above the X-axis but rather
on top of the previous element.  There must be something to stack
upon.

An B<invisible> LINEx or AREA B<is> present and can be stacked upon.  

An B<unknown> value makes the entire stack unknown from that moment on.
You don't know where to begin (the unknown value) and therefore do
not know where to end.

If you want to make sure you will be displaying a certain variable,
make sure never to stack upon the unknown value.  Use a CDEF instruction
with B<IF> and B<UN> to do so.

=head1 NOTES on legend arguments

=head2 Escaping the colon

In a ':' in a I<legend> argument will mark the end of the legend. To
enter a ':' into a legend, the colon must be escaped with a backslash '\:'.
Beware, that many environments look for backslashes themselves, so it may
be necessary to write two backslashes so that one is passed onto rrd_graph.

=head2 String Formatting

The text printed below the actual graph can be formated by appending special
escaped characters at the end of a text. When ever such a character occurs,
all pending text is pushed onto the graph according to the character
specified.

Valid markers are: B<\j> for justified, B<\l> for left aligned, B<\r> for
right aligned and B<\c> for centered. In the next section there is an
example showing how to use centered formating.

Normally there are two space characters inserted between every two items
printed into the graph. The space following a string can be suppressed by
putting a B<\g> at the end of the string. The B<\g> also ignores any space
inside the string if it is at the very end of the string. This can be used
in connection with B<%s> to suppress empty unit strings.

 GPRINT:a:MAX:%lf%s\g

A special case is COMMENT:B<\s> this inserts some additional vertical space
before placing the next row of legends.

If you are using the proportional font in your graph, you can use tab characters
or the sequence B<\t> to lin-up legend elements. Note that the tabs inserted are
relative to the start of the current legend element!

=head1 SEE ALSO

L<rrdgraph> gives an overview of how B<rrdtool graph> works.
L<rrdgraph_data> describes B<DEF>,B<CDEF> and B<VDEF> in detail,
L<rrdgraph_rpn> describes the B<RPN> language used in the B<?DEF> statements,
L<rrdgraph_graph> page describes all of the graph and print functions.

Make sure to read L<rrdgraph_examples> for tipsE<amp>tricks.

=head1 AUTHOR

Program by Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>

This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>