add some shell proggramming advice ... Bernhard Reutner-Fischer

[rrdtool.git] / doc / rrdgraph.pod

diff --git a/doc/rrdgraph.pod b/doc/rrdgraph.pod
index bd0d0d4..57359ac 100644 (file)
--- a/doc/rrdgraph.pod
+++ b/doc/rrdgraph.pod
@@ -4,7 +4,7 @@ rrdgraph - Round Robin Database tool grapher functions
 
 =head1 SYNOPSIS
 
 
 =head1 SYNOPSIS
 

-B<rrdtool graph> I<filename>
+B<rrdtool graph|graphv> I<filename>

 [I<L<option|rrdgraph/OPTIONS>> ...]
 [I<L<data definition|rrdgraph_data/DEF>> ...]
 [I<L<data calculation|rrdgraph_data/CDEF>> ...]
 [I<L<option|rrdgraph/OPTIONS>> ...]
 [I<L<data definition|rrdgraph_data/DEF>> ...]
 [I<L<data calculation|rrdgraph_data/CDEF>> ...]


@@ -16,70 +16,73 @@ B<rrdtool graph> I<filename>
 
 The B<graph> function of B<RRDtool> is used to present the
 data from an B<RRD> to a human viewer.  Its main purpose is to
 
 The B<graph> function of B<RRDtool> is used to present the
 data from an B<RRD> to a human viewer.  Its main purpose is to

-create a nice graphical representation but it can also generate
+create a nice graphical representation, but it can also generate

 a numerical report.
 
 =head1 OVERVIEW
 
 a numerical report.
 
 =head1 OVERVIEW
 

-B<rrdtool graph> needs data to work with, use one or more
+B<rrdtool graph> needs data to work with, so you must use one or more

 B<L<data definition|rrdgraph_data/DEF>> statements to collect this
 data.  You are not limited to one database, it's perfectly legal to
 B<L<data definition|rrdgraph_data/DEF>> statements to collect this
 data.  You are not limited to one database, it's perfectly legal to

-collect data from two or more databases (one per statement though).
+collect data from two or more databases (one per statement, though).

 
 

-If you want to display averages, maxima, percentiles etcetera
+If you want to display averages, maxima, percentiles, etcetera

 it is best to collect them now using the
 B<L<variable definition|rrdgraph_data/VDEF>> statement.
 it is best to collect them now using the
 B<L<variable definition|rrdgraph_data/VDEF>> statement.

-Currently this makes no difference but in a future version
+Currently this makes no difference, but in a future version

 of rrdtool you may want to collect these values before consolidation.
 
 The data fetched from the B<RRA> is then B<consolidated> so that
 there is exactly one datapoint per pixel in the graph. If you do
 not take care yourself, B<RRDtool> will expand the range slightly
 of rrdtool you may want to collect these values before consolidation.
 
 The data fetched from the B<RRA> is then B<consolidated> so that
 there is exactly one datapoint per pixel in the graph. If you do
 not take care yourself, B<RRDtool> will expand the range slightly

-if necessary (in that case the first and/or last pixel may very
-well become unknown!).
-
-Sometimes data is not exactly as you would like to display it. For
-instance, you might be collecting B<bytes> per second but want to
-display B<bits> per second. This is where the
-B<L<data calculation|rrdgraph_data/CDEF>> command is designed for.
-After B<consolidating> the data, a copy is made and this copy is
-modified using a rather flexible B<L<RPN|rrdgraph_rpn/>> command
-set.
+if necessary. Note, in that case the first and/or last pixel may very
+well become unknown!
+
+Sometimes data is not exactly in the format you would like to display
+it. For instance, you might be collecting B<bytes> per second, but
+want to display B<bits> per second. This is what the B<L<data
+calculation|rrdgraph_data/CDEF>> command is designed for. After
+B<consolidating> the data, a copy is made and this copy is modified
+using a rather powerful B<L<RPN|rrdgraph_rpn>> command set.

 
 When you are done fetching and processing the data, it is time to
 graph it (or print it).  This ends the B<rrdtool graph> sequence.
 
 
 When you are done fetching and processing the data, it is time to
 graph it (or print it).  This ends the B<rrdtool graph> sequence.
 

+Use B<graphv> instead of B<graph> to get detailed information about the
+graph geometry and data once it is drawn. See the bottom of the document for
+more information.
+

 =head1 OPTIONS
 
 =head1 OPTIONS
 

-=over 4

 
 

-=item filename
+
+=head2 I<filename>

 
 The name and path of the graph to generate. It is recommended to
 
 The name and path of the graph to generate. It is recommended to

-end this in C<.png>, C<.svg> or C<.eps> but B<RRDtool> does not enforce this.
+end this in C<.png>, C<.svg> or C<.eps>, but B<RRDtool> does not enforce this.

 
 I<filename> can be 'C<->' to send the image to C<stdout>. In
 
 I<filename> can be 'C<->' to send the image to C<stdout>. In

-that case, no other output is generated.  
+this case, no other output is generated.

 
 

-=item Time range
+=head2 Time range

 
 [B<-s>|B<--start> I<time>]
 [B<-e>|B<--end> I<time>]
 [B<-S>|B<--step> I<seconds>]
 
 
 [B<-s>|B<--start> I<time>]
 [B<-e>|B<--end> I<time>]
 [B<-S>|B<--step> I<seconds>]
 

-The start and end of what you would like to display, and which
+The start and end of the time series you would like to display, and which

 B<RRA> the data should come from.  Defaults are: 1 day ago until
 B<RRA> the data should come from.  Defaults are: 1 day ago until

-now, with the best possible resolution. B<Start> and B<end> can 
+now, with the best possible resolution. B<Start> and B<end> can

 be specified in several formats, see
 be specified in several formats, see

-L<AT-STYLE TIME SPECIFICATION|rrdfetch/> and L<rrdgraph_examples>.
+L<AT-STYLE TIME SPECIFICATION|rrdfetch> and L<rrdgraph_examples>.

 By default, B<rrdtool graph> calculates the width of one pixel in
 the time domain and tries to get data from an B<RRA> with that
 resolution.  With the B<step> option you can alter this behaviour.
 If you want B<rrdtool graph> to get data at a one-hour resolution
 By default, B<rrdtool graph> calculates the width of one pixel in
 the time domain and tries to get data from an B<RRA> with that
 resolution.  With the B<step> option you can alter this behaviour.
 If you want B<rrdtool graph> to get data at a one-hour resolution

-from the B<RRD>, set B<step> to 3600.  Note: a step smaller than
+from the B<RRD>, set B<step> to 3'600. Note: a step smaller than

 one pixel will silently be ignored.
 
 one pixel will silently be ignored.
 

-=item Labels
+=head2 Labels

 
 [B<-t>|B<--title> I<string>]
 [B<-v>|B<--vertical-label> I<string>]
 
 [B<-t>|B<--title> I<string>]
 [B<-v>|B<--vertical-label> I<string>]


@@ -87,41 +90,56 @@ one pixel will silently be ignored.
 A horizontal string at the top of the graph and/or a vertically
 placed string at the left hand side of the graph.
 
 A horizontal string at the top of the graph and/or a vertically
 placed string at the left hand side of the graph.
 

-=item Size
+
+=head2 Size

 
 [B<-w>|B<--width> I<pixels>]
 [B<-h>|B<--height> I<pixels>]
 [B<-j>|B<--only-graph>]
 
 [B<-w>|B<--width> I<pixels>]
 [B<-h>|B<--height> I<pixels>]
 [B<-j>|B<--only-graph>]

+[B<-D>|B<--full-size-mode>]
+
+By default, the width and height of the B<canvas> (the part with
+the actual data and such). This defaults to 400 pixels by 100 pixels.

 
 

-The width and height of the B<canvas> (the part of the graph with
-the actual lines and such). Defaults are 400 pixels by 100 pixels.
+If you specify the B<--full-size-mode> option, the width and height
+specify the final dimensions of the output image and the canvas
+is automatically resized to fit.

 
 If you specify the B<--only-graph> option and set the height E<lt> 32
 
 If you specify the B<--only-graph> option and set the height E<lt> 32

-pixels you will get a tiny graph image to use as an icon in a potential
-overview. All labeling will be stripped off the graph.
+pixels you will get a tiny graph image (thumbnail) to use as an icon
+for use in an overview, for example. All labeling will be stripped off
+the graph.

 
 

-=item Limits
+=head2 Limits

 
 [B<-u>|B<--upper-limit> I<value>]
 [B<-l>|B<--lower-limit> I<value>]
 [B<-r>|B<--rigid>]
 
 
 [B<-u>|B<--upper-limit> I<value>]
 [B<-l>|B<--lower-limit> I<value>]
 [B<-r>|B<--rigid>]
 

-By default the graph will be autoscaling so that it displays the
-portion of the y-axis that is actually used. You can change this
-behaviour by setting the limits.  The displayed y-axis will show
-at least from B<lower-limit> to B<upper-limit>.  Autoscaling will
-still permit those boundaries to be stretched unless the B<rigid>
-option is set.
+By default the graph will be autoscaling so that it will adjust the
+y-axis to the range of the data. You can change this behaviour by
+explicitly setting the limits. The displayed y-axis will then range at
+least from B<lower-limit> to B<upper-limit>. Autoscaling will still
+permit those boundaries to be stretched unless the B<rigid> option is
+set.

 
 [B<-A>|B<--alt-autoscale>]
 
 Sometimes the default algorithm for selecting the y-axis scale is not
 
 [B<-A>|B<--alt-autoscale>]
 
 Sometimes the default algorithm for selecting the y-axis scale is not

-performing very well.  Normally the scale is selected from a predefined
+satisfactory. Normally the scale is selected from a predefined

 set of ranges and this fails miserably when you need to graph something
 like C<260 + 0.001 * sin(x)>. This option calculates the minimum and
 set of ranges and this fails miserably when you need to graph something
 like C<260 + 0.001 * sin(x)>. This option calculates the minimum and

-maximum y-axis from the actual minimum and maximum values. Our example
+maximum y-axis from the actual minimum and maximum data values. Our example

 would display slightly less than C<260-0.001> to slightly more than
 would display slightly less than C<260-0.001> to slightly more than

-C<260+0.001> (Contributed by Sasha Mikheev).
+C<260+0.001> (this feature was contributed by Sasha Mikheev).
+
+[B<-J>|B<--alt-autoscale-min>]
+
+Where C<--alt-autoscale> will modify both the absolute maximum AND minimum
+values, this option will only affect the minimum value. The maximum
+value, if not defined on the command line, will be 0. This option can
+be useful when graphing router traffic when the WAN line uses compression,
+and thus the throughput may be higher than the WAN line speed.

 
 [B<-M>|B<--alt-autoscale-max>]
 
 
 [B<-M>|B<--alt-autoscale-max>]
 


@@ -133,27 +151,22 @@ and thus the throughput may be higher than the WAN line speed.
 
 [B<-N>|B<--no-gridfit>]
 
 
 [B<-N>|B<--no-gridfit>]
 

-To avoid anti-aliasing effects gridlines are placed on 
-integer pixel values. This is by default done by extending 
-the scale so gridlines happens to be spaced using an 
-integer number of pixels, and starts on integer pixel value.
-This might extend the scale too much for some logarithmic scales
-and for linear scales where B<--alt-autoscale> is needed.
-Using B<--no-gridfit> disables modification of the scale.
+In order to avoid anti-aliasing blurring effects rrdtool snaps
+points to device resolution pixels, this results in a crisper
+appearance. If this is not to your liking, you can use this switch
+to turn this behaviour off.

 
 

-=item Grid
+Gridfitting is turned off for PDF, EPS, SVG output by default.

 
 

-=over 4
-
-=item X-Axis
+=head2 X-Axis

 
 [B<-x>|B<--x-grid> I<GTM>B<:>I<GST>B<:>I<MTM>B<:>I<MST>B<:>I<LTM>B<:>I<LST>B<:>I<LPR>B<:>I<LFM>]
 
 [B<-x>|B<--x-grid> B<none>]
 
 
 [B<-x>|B<--x-grid> I<GTM>B<:>I<GST>B<:>I<MTM>B<:>I<MST>B<:>I<LTM>B<:>I<LST>B<:>I<LPR>B<:>I<LFM>]
 
 [B<-x>|B<--x-grid> B<none>]
 

-The x-axis label is quite complex to configure, if you don't have
+The x-axis label is quite complex to configure. If you don't have

 very special needs it is probably best to rely on the autoconfiguration
 very special needs it is probably best to rely on the autoconfiguration

-to get this right.  You can specify the string C<none> to skip the grid
+to get this right. You can specify the string C<none> to suppress the grid

 and labels altogether.
 
 The grid is defined by specifying a certain amount of time in the I<?TM>
 and labels altogether.
 
 The grid is defined by specifying a certain amount of time in the I<?TM>


@@ -161,26 +174,26 @@ positions. You can choose from C<SECOND>, C<MINUTE>, C<HOUR>, C<DAY>,
 C<WEEK>, C<MONTH> or C<YEAR>. Then you define how many of these should
 pass between each line or label.  This pair (I<?TM:?ST>) needs to be
 specified for the base grid (I<G??>), the major grid (I<M??>) and the
 C<WEEK>, C<MONTH> or C<YEAR>. Then you define how many of these should
 pass between each line or label.  This pair (I<?TM:?ST>) needs to be
 specified for the base grid (I<G??>), the major grid (I<M??>) and the

-labels (I<L??>). For the labels you also need to define a precision
+labels (I<L??>). For the labels you also must define a precision

 in I<LPR> and a I<strftime> format string in I<LFM>.  I<LPR> defines
 where each label will be placed. If it is zero, the label will be
 placed right under the corresponding line (useful for hours, dates
 etcetera).  If you specify a number of seconds here the label is
 in I<LPR> and a I<strftime> format string in I<LFM>.  I<LPR> defines
 where each label will be placed. If it is zero, the label will be
 placed right under the corresponding line (useful for hours, dates
 etcetera).  If you specify a number of seconds here the label is

-centered in this interval (useful for Monday, January etcetera).
+centered on this interval (useful for Monday, January etcetera).

 
  --x-grid MINUTE:10:HOUR:1:HOUR:4:0:%X
 
 
  --x-grid MINUTE:10:HOUR:1:HOUR:4:0:%X
 

-This places grid lines every 10 minutes, major grid lines every hour
+This places grid lines every 10 minutes, major grid lines every hour,

 and labels every 4 hours. The labels are placed under the major grid
 lines as they specify exactly that time.
 
 and labels every 4 hours. The labels are placed under the major grid
 lines as they specify exactly that time.
 

- --x-grid HOUR:8:DAY:1:DAY:1:0:%A
+ --x-grid HOUR:8:DAY:1:DAY:1:86400:%A

 
 This places grid lines every 8 hours, major grid lines and labels
 each day. The labels are placed exactly between two major grid lines
 as they specify the complete day and not just midnight.
 
 
 This places grid lines every 8 hours, major grid lines and labels
 each day. The labels are placed exactly between two major grid lines
 as they specify the complete day and not just midnight.
 

-=item Y-Axis
+=head2 Y-Axis

 
 [B<-y>|B<--y-grid> I<grid step>B<:>I<label factor>]
 
 
 [B<-y>|B<--y-grid> I<grid step>B<:>I<label factor>]
 


@@ -188,15 +201,21 @@ as they specify the complete day and not just midnight.
 
 Y-axis grid lines appear at each I<grid step> interval.  Labels are
 placed every I<label factor> lines.  You can specify C<-y none> to
 
 Y-axis grid lines appear at each I<grid step> interval.  Labels are
 placed every I<label factor> lines.  You can specify C<-y none> to

-skip the grid and labels altogether.  The default for this option is
+suppress the grid and labels altogether.  The default for this option is

 to automatically select sensible values.
 
 to automatically select sensible values.
 

+If you have set --y-grid to 'none' not only the labels get suppressed, also
+the space reserved for the labels is removed. You can still add space
+manually if you use the --units-length command to explicitly reserve space.
+

 [B<-Y>|B<--alt-y-grid>]
 
 [B<-Y>|B<--alt-y-grid>]
 

-Place Y grid dynamically based on graph Y range. Algorithm ensures
-that you always have grid, that there are enough but not too many
-grid lines and the grid is metric. That is grid lines are placed
-every 1, 2, 5 or 10 units.  (contributed by Sasha Mikheev)
+Place the Y grid dynamically based on the graph's Y range. The algorithm
+ensures that you always have a grid, that there are enough but not too many
+grid lines, and that the grid is metric. That is the grid lines are placed
+every 1, 2, 5 or 10 units. This parameter will also ensure that you get
+enough decimals displayed even if your graph goes from 69.998 to 70.001. 
+(contributed by Sasha Mikheev).

 
 [B<-o>|B<--logarithmic>]
 
 
 [B<-o>|B<--logarithmic>]
 


@@ -204,12 +223,12 @@ Logarithmic y-axis scaling.
 
 [B<-X>|B<--units-exponent> I<value>]
 
 
 [B<-X>|B<--units-exponent> I<value>]
 

-This sets the 10**exponent scaling of the y-axis values.  Normally
-values will be scaled to the appropriate units (k, M, etc.).  However
+This sets the 10**exponent scaling of the y-axis values. Normally,
+values will be scaled to the appropriate units (k, M, etc.).  However,

 you may wish to display units always in k (Kilo, 10e3) even if the data
 you may wish to display units always in k (Kilo, 10e3) even if the data

-is in the M (Mega, 10e6) range for instance.  Value should be an
-integer which is a multiple of 3 between -18 and 18 inclusive.  It is
-the exponent on the units you which to use.  For example, use 3 to
+is in the M (Mega, 10e6) range, for instance. Value should be an
+integer which is a multiple of 3 between -18 and 18 inclusively.  It is
+the exponent on the units you wish to use. For example, use 3 to

 display the y-axis values in k (Kilo, 10e3, thousands), use -6 to
 display the y-axis values in u (Micro, 10e-6, millionths).  Use a value
 of 0 to prevent any scaling of the y-axis values.
 display the y-axis values in k (Kilo, 10e3, thousands), use -6 to
 display the y-axis values in u (Micro, 10e-6, millionths).  Use a value
 of 0 to prevent any scaling of the y-axis values.


@@ -221,23 +240,80 @@ to the more robust B<--alt-y-grid> mode.
 
 [B<-L>|B<--units-length> I<value>]
 
 
 [B<-L>|B<--units-length> I<value>]
 

-How many digits should rrdtool assume the y-axis labels to be ? You may have to use this option
-to make enough space once you start fideling with the y-axis labeling.
+How many digits should rrdtool assume the y-axis labels to be? You
+may have to use this option to make enough space once you start
+fiddling with the y-axis labeling.

 
 

-=back
+[B<--units=si>]
+
+With this option y-axis values on logarithmic graphs will be scaled to 
+the appropriate units (k, M, etc.) instead of using exponential notation.
+Note that for linear graphs, SI notation is used by default.

 
 

-=item Miscellaneous
+=head2 Right Y Axis
+
+[B<--right-axis> I<scale>B<:>I<shift>]
+[B<--right-axis-label> I<label>]
+
+A second axis will be drawn to the right of the graph. It is tied to the
+left axis via the scale and shift parameters. You can also define a label
+for the right axis.
+
+[B<--right-axis-format> I<format-string>]
+
+By default the format of the axis lables gets determined automatically. If
+you want todo this your self, use this option with the same %lf arguments
+you know from the PRING and GPRINT commands.
+
+=head2 Legend
+
+[B<-g>|B<--no-legend>]
+
+Suppress generation of the legend; only render the graph.
+
+[B<-F>|B<--force-rules-legend>]
+
+Force the generation of HRULE and VRULE legends even if those HRULE or
+VRULE will not be drawn because out of graph boundaries (mimics
+behaviour of pre 1.0.42 versions).
+
+[B<--legend-position>=(north|south|west|east)]
+
+Place the legend at the given side of the graph. The default is south.
+In west or east position it is necessary to add line breaks manually.
+
+[B<--legend-direction>=(topdown|bottomup)]
+
+Place the legend items in the given vertical order. The default is topdown.
+Using bottomup the legend items appear in the same vertical order as a
+stack of lines or areas.
+
+=head2 Miscellaneous

 
 [B<-z>|B<--lazy>]
 
 
 [B<-z>|B<--lazy>]
 

-Only generate the graph, if the current graph is out of date or not
-existent.
+Only generate the graph if the current graph is out of date or not existent.
+Note, that all the calculations will happen regardless so that the output of
+PRINT and graphv will be complete regardless. Note that the behaviour of
+lazy in this regard has seen several changes over time. The only thing you
+can realy rely on before rrdtool 1.3.7 is that lazy will not generate the
+graph when it is already there and up to date, and also that it will output
+the size of the graph. 
+
+[B<--daemon> I<address>]
+
+Address of the L<rrdcached> daemon. If specified, a C<flush> command is sent
+to the server before reading the RRD files. This allows the graph to contain
+fresh data even if the daemon is configured to cache values for a long time.
+For a list of accepted formats, see the B<-l> option in the L<rrdcached> manual.
+
+ rrdtool graph [...] --daemon unix:/var/run/rrdcached.sock [...]

 
 [B<-f>|B<--imginfo> I<printfstr>]
 
 After the image has been created, the graph function uses printf
 together with this format string to create output similar to the PRINT
 
 [B<-f>|B<--imginfo> I<printfstr>]
 
 After the image has been created, the graph function uses printf
 together with this format string to create output similar to the PRINT

-function, only that the printf is supplied with the parameters
+function, only that the printf function is supplied with the parameters

 I<filename>, I<xsize> and I<ysize>. In order to generate an B<IMG> tag
 suitable for including the graph into a web page, the command line
 would look like this:
 I<filename>, I<xsize> and I<ysize>. In order to generate an B<IMG> tag
 suitable for including the graph into a web page, the command line
 would look like this:


@@ -250,51 +326,123 @@ Override the default colors for the standard elements of the graph. The
 I<COLORTAG> is one of C<BACK> background, C<CANVAS> for the background of
 the actual graph, C<SHADEA> for the left and top border, C<SHADEB> for the
 right and bottom border, C<GRID>, C<MGRID> for the major grid, C<FONT> for
 I<COLORTAG> is one of C<BACK> background, C<CANVAS> for the background of
 the actual graph, C<SHADEA> for the left and top border, C<SHADEB> for the
 right and bottom border, C<GRID>, C<MGRID> for the major grid, C<FONT> for

-the color of the font, C<AXIS> for the axis of the graph and finaly C<ARROW>
-for the arrow head pointing to the future. Each color is composed out of
-three hexadecimal numbers specifying its color component (00 is off, FF is
-maximum) of red, green and blue. Optionally you may add another hexadecimal
-number specifying the transparency (FF is solid). You may set this option
-several times to alter multiple defaults.
+the color of the font, C<AXIS> for the axis of the graph, C<FRAME> for the
+line around the color spots, and finally C<ARROW> for the arrow head pointing
+up and forward. Each color is composed out of three hexadecimal numbers
+specifying its rgb color component (00 is off, FF is maximum) of red, green
+and blue. Optionally you may add another hexadecimal number specifying the
+transparency (FF is solid). You may set this option several times to alter
+multiple defaults.

 
 

-A green arrow is made by: C<--color ARROW:00FF00>
+A green arrow is made by: C<--color ARROW#00FF00>

 
 [B<--zoom> I<factor>]
 
 
 [B<--zoom> I<factor>]
 

-Zoom the graphics by the given amount ... The factor must be E<gt> 0
+Zoom the graphics by the given amount. The factor must be E<gt> 0
+
+[B<-n>|B<--font> I<FONTTAG>B<:>I<size>B<:>[I<font>]]
+
+This lets you customize which font to use for the various text elements on
+the RRD graphs. C<DEFAULT> sets the default value for all elements, C<TITLE>
+for the title, C<AXIS> for the axis labels, C<UNIT> for the vertical unit
+label, C<LEGEND> for the graph legend, C<WATERMARK> for the watermark on the
+edge of the graph.

 
 

-[B<-n>|B<--font> I<FONTTAG>B<:>I<size>B<:>I<font>]
+Use Times for the title: C<--font TITLE:13:Times>

 
 

-Lets you customize which font to use for the various text elements on the
-RRD graphs. C<DEFAULT> sets the default value for all elements C<TITLE>,
-C<AXIS> for the axis labels, C<UNIT> for the vertical unit label, C<LEGEND>
-for the graph legend.
+Note that you need to quote the argument to B<--font> if the font-name
+contains whitespace:
+--font "TITLE:13:Some Font"

 
 

-Use Times for the title: C<--font TITLE:13:/usr/lib/fonts/times.ttf>
+If you do not give a font string you can modify just the size of the default font:
+C<--font TITLE:13:>.
+
+If you specify the size 0 then you can modify just the font without touching
+the size. This is especially useful for altering the default font without
+resetting the default fontsizes: C<--font DEFAULT:0:Courier>.

 
 RRDtool comes with a preset default font. You can set the environment
 variable C<RRD_DEFAULT_FONT> if you want to change this.
 
 
 RRDtool comes with a preset default font. You can set the environment
 variable C<RRD_DEFAULT_FONT> if you want to change this.
 

-Truetype fonts are only supported for PNG output. See below.
+RRDtool uses Pango for its font handling. This means you can to use
+the full Pango syntax when selecting your font:

 
 

-[B<-a>|B<--imgformat> B<PNG>|B<SVG>|B<EPS>|B<PDF>]
+The font name has the form "[I<FAMILY-LIST>] [I<STYLE-OPTIONS>] [I<SIZE>]",
+where I<FAMILY-LIST> is a comma separated list of families optionally
+terminated by a comma, I<STYLE_OPTIONS> is a whitespace separated list of
+words where each WORD describes one of style, variant, weight, stretch, or
+gravity, and I<SIZE> is a decimal number (size in points) or optionally
+followed by the unit modifier "px" for absolute size. Any one of the options
+may be absent.

 
 

-Image format for the generated graph. For the vector formats you can choose among the standard Postscript fonts
-Courier-Bold, Courier-BoldOblique, Courier-Oblique, Courier, Helvetica-Bold,
-Helvetica-BoldOblique, Helvetica-Oblique, Helvetica, Symbol, Times-Bold, Times-BoldItalic,
-Times-Italic, Times-Roman, ZapfDingbats 
+[B<-R>|B<--font-render-mode> {B<normal>,B<light>,B<mono>}]

 
 

-[B<-i>|B<--interlaced>]
+There are 3 font render modes:

 
 

-If images are interlaced they become visible on browsers more quickly.
+B<normal>: Full Hinting and Antialiasing (default)

 
 

-[B<-g>|B<--no-legend>]
+B<light>: Slight Hinting and Antialiasing

 
 

-Suppress generation of legend; only render the graph.
+B<mono>: Full Hinting and NO Antialiasing

 
 

-[B<-F>|B<--force-rules-legend>]

 
 

-Force the generation of HRULE and VRULE legend even if those HRULE or VRULE will not be drawn because out of graph boundaries (mimics behaviour of pre 1.0.42 versions).
+[B<-B>|B<--font-smoothing-threshold> I<size>]
+
+(this gets ignored in 1.3 for now!)
+
+This specifies the largest font size which will be rendered
+bitmapped, that is, without any font smoothing. By default,
+no text is rendered bitmapped.
+
+[B<-P>|B<--pango-markup>]
+
+All text in rrdtool is rendered using Pango. With the B<--pango-markup> option, all
+text will be processed by pango markup. This allows to embed some simple html
+like markup tags using 
+
+ <span key="value">text</span>
+
+Apart from the verbose syntax, there are also the following short tags available.
+
+ b     Bold
+ big   Makes font relatively larger, equivalent to <span size="larger">
+ i     Italic
+ s     Strikethrough
+ sub   Subscript
+ sup   Superscript
+ small Makes font relatively smaller, equivalent to <span size="smaller">
+ tt    Monospace font
+ u     Underline 
+
+More details on L<http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html>.
+
+[B<-G>|B<--graph-render-mode> {B<normal>,B<mono>}]
+
+There are 2 render modes:
+
+B<normal>: Graphs are fully Antialiased (default)
+
+B<mono>: No Antialiasing
+
+[B<-E>|B<--slope-mode>]
+
+RRDtool graphs are composed of stair case curves by default. This is in line with
+the way RRDtool calculates its data. Some people favor a more 'organic' look
+for their graphs even though it is not all that true.
+
+[B<-a>|B<--imgformat> B<PNG>|B<SVG>|B<EPS>|B<PDF>]
+
+Image format for the generated graph. For the vector formats you can
+choose among the standard Postscript fonts Courier-Bold,
+Courier-BoldOblique, Courier-Oblique, Courier, Helvetica-Bold,
+Helvetica-BoldOblique, Helvetica-Oblique, Helvetica, Symbol,
+Times-Bold, Times-BoldItalic, Times-Italic, Times-Roman, and ZapfDingbats.
+
+[B<-i>|B<--interlaced>]
+
+(this gets ignored in 1.3 for now!)
+
+If images are interlaced they become visible on browsers more quickly.

 
 [B<-T>|B<--tabwidth> I<value>]
 
 
 [B<-T>|B<--tabwidth> I<value>]
 


@@ -306,7 +454,12 @@ If you are graphing memory (and NOT network traffic) this switch
 should be set to 1024 so that one Kb is 1024 byte. For traffic
 measurement, 1 kb/s is 1000 b/s.
 
 should be set to 1024 so that one Kb is 1024 byte. For traffic
 measurement, 1 kb/s is 1000 b/s.
 

-=item Data and variables
+[B<-W>|B<--watermark> I<string>]
+
+Adds the given string as a watermark, horizontally centered, at the bottom 
+of the graph.
+
+=head2 Data and variables

 
 B<DEF:>I<vname>B<=>I<rrdfile>B<:>I<ds-name>B<:>I<CF>[B<:step=>I<step>][B<:start=>I<time>][B<:end=>I<time>]
 
 
 B<DEF:>I<vname>B<=>I<rrdfile>B<:>I<ds-name>B<:>I<CF>[B<:step=>I<step>][B<:start=>I<time>][B<:end=>I<time>]
 


@@ -316,28 +469,72 @@ B<VDEF:>I<vname>B<=>I<RPN expression>
 
 You need at least one B<DEF> statement to generate anything. The
 other statements are useful but optional.
 
 You need at least one B<DEF> statement to generate anything. The
 other statements are useful but optional.

-See L<rrdgraph_data> and L<rrdgraph_rpn> for exact format.
+See L<rrdgraph_data> and L<rrdgraph_rpn> for the exact format.

 
 

-=item Graph and print elements
+NOTE: B<Graph and print elements>

 
 You need at least one graph element to generate an image and/or
 at least one print statement to generate a report.
 
 You need at least one graph element to generate an image and/or
 at least one print statement to generate a report.

-See L<rrdgraph_graph> for exact format.
+See L<rrdgraph_graph> for the exact format.
+
+=head2 graphv
+
+Calling rrdtool with the graphv option will return information in the
+rrdtool info format. On the command line this means that all output will be
+in key=value format. When used from the Perl and Ruby bindings a hash
+pointer will be returned from the call.
+
+When the filename '-' is given, the contents of the graph itself will also
+be returned through this interface (hash key 'image'). On the command line
+the output will look like this:
+
+ print[0] = "0.020833"
+ print[1] = "0.0440833"
+ graph_left = 51
+ graph_top = 22
+ graph_width = 400
+ graph_height = 100
+ graph_start = 1232908800
+ graph_end = 1232914200
+ image_width = 481
+ image_height = 154
+ value_min = 0.0000000000e+00
+ value_max = 4.0000000000e-02
+ image = BLOB_SIZE:8196
+ [... 8196 bytes of image data ...]
+
+There is more information returned than in the standard interface.
+Especially the 'graph_*' keys are new. They help applications that want to
+know what is where on the graph.
+
+=head1 ENVIRONMENT VARIABLES
+
+The following environment variables may be used to change the behavior of
+C<rrdtoolE<nbsp>graph>:
+
+=over 4
+
+=item B<RRDCACHED_ADDRESS>
+
+If this environment variable is set it will have the same effect as specifying
+the C<--daemon> option on the command line. If both are present, the command
+line argument takes precedence.

 
 =back
 
 =head1 SEE ALSO
 
 L<rrdgraph> gives an overview of how B<rrdtool graph> works.
 
 =back
 
 =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_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
 
 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>
+Program by Tobias Oetiker E<lt>tobi@oetiker.chE<gt>

 
 

-This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>
+This manual page by Alex van den Bogaerdt E<lt>alex@vandenbogaerdt.nlE<gt>
+with corrections and/or additions by several people