Depending on the context, either the value component or the time
component of a VDEF is printed using format. It is an error
to specify a vname generated by a DEF or CDEF.
Any text in format is printed literally with one exception: The percent character introduces a formatter string. This string can be:
For printing values:
%% - just prints a literal % character
%#.#le - prints numbers like 1.2346e+04. The optional integers # denote field width and decimal precision.
%#.#lf - prints numbers like 12345.6789, with optional field width and precision.
%s - place this after %le, %lf or %lg. This will be replaced by the appropriate SI magnitude unit and the value will be scaled accordingly (123456 -> 123.456 k).
%S - is similar to %s. It does, however, use a previously defined magnitude unit. If there is no such unit yet, it tries to define one (just like %s) unless the value is zero, in which case the magnitude unit stays undefined. Thus, formatter strings using %S and no %s will all use the same magnitude unit except for zero values.
If you PRINT a VDEF value, you can also print the time associated with it by appending the string :strftime to the format. Note that rrdtool uses the strftime function of your OSs clibrary. This means that the conversion specifier may vary. Check the manual page if you are uncertain. The following is a list of conversion specifiers usually supported across the board.
%a - The abbreviated weekday name according to the current locale.
%A - The full weekday name according to the current locale.
%b - The abbreviated month name according to the current locale.
%B - The full month name according to the current locale.
%c - The preferred date and time representation for the current locale.
%d - The day of the month as a decimal number (range 01 to 31).
%H - The hour as a decimal number using a 24-hour clock (range 00 to 23).
%I - The hour as a decimal number using a 12-hour clock (range 01 to 12).
%j - The day of the year as a decimal number (range 001 to 366).
%m - The month as a decimal number (range 01 to 12).
%M - The minute as a decimal number (range 00 to 59).
%p - Either AM or PM according to the given time value, or the corresponding strings for the current locale. Noon is treated as pm and midnight as am. Note that in many locales and pm notation is unsupported and in such cases %p will return an empty string.
%S - The second as a decimal number (range 00 to 61).
%U - The week number of the current year as a decimal number, range 00 to 53, starting with the first Sunday as the first day of week 01. See also %V and %W.
%V - The ISO 8601:1988 week number of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the current year, and with Monday as the first day of the week. See also %U and %W.
%w - The day of the week as a decimal, range 0 to 6, Sunday being 0. See also %u.
%W - The week number of the current year as a decimal number, range 00 to 53, starting with the first Monday as the first day of week 01.
%x - The preferred date representation for the current locale without the time.
%X - The preferred time representation for the current locale without the date.
%y - The year as a decimal number without a century (range 00 to 99).
%Y - The year as a decimal number including the century.
%Z - The time zone or name or abbreviation.
%% - A literal % character.
|PRINT:vname:CF:format||Deprecated. Use the new form of this command in new scripts. The first form of this command is to be used with CDEF vnames.|
Some notes on stacking
GPRINT:vname:format This is the same as PRINT, but printed inside the graph. GPRINT:vname:CF:format Deprecated. Use the new form of this command in new scripts. This is the same as PRINT, but printed inside the graph. COMMENT:text Text is printed literally in the legend section of the graph. Note that in RRDtool 1.2 you have to escape colons in COMMENT text in the same way you have to escape them in *PRINT commands by writing \:. VRULE:time#color [:legend ] Draw a vertical line at time. Its color is composed from three hexadecimal numbers specifying the rgb color components (00 is off, FF is maximum) red, green and blue followed by an optional alpha. Optionally, a legend box and string is printed in the legend section. time may be a number or a variable from a VDEF. It is an error to use vnames from DEF or CDEF here. HRULE:value#color [ :legend ] Draw a horizontal line at value. HRULE acts much like LINE except that will have no effect on the scale of the graph. If a HRULE is outside the graphing area it will just not be visible. LINE[width]:value[#color][:[legend][:STACK]] Draw a line of the specified width onto the graph. width can be a floating point number. If the color is not specified, the drawing is done invisibly. 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 value can be generated by DEF, VDEF, and CDEF. If the optional STACK modifier is used, this line is stacked on top of the previous element which can be a LINE or an AREA.
When you do not specify a color, you cannot specify a legend. Should you want to use STACK, use the LINEx:<value>::STACK form.
AREA:value[#color][:[legend][:STACK]] See LINE, however the area between the x-axis and the line will be filled. TICK:vname#rrggbb[aa][:fraction[:legend]] Plot a tick mark (a vertical line) for each value of vname that is non-zero and not *UNKNOWN*. The 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. The TICK marks normaly start at the lower edge of the graphing area. If the fraction is negative they start at the upper border of the graphing area. SHIFT:vname:offset Using this command RRDtool will graph the following elements with the specified offset. For instance, you can specify an offset of ( 7*24*60*60 = ) 604800 seconds to look back one week. Make sure to tell the viewer of your graph you did this ... As with the other graphing elements, you can specify a number or a variable here. STACK:vname#color[:legend] Deprecated. Use the STACK modifiers on the other commands.
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.
You can use an invisible LINE or AREA to stacked upon.
An unknown value makes the entire stack unknown from that moment on. You dont 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 IF and UN to do so.
A colon : in a legend argument will mark the end of the legend. To enter a : as part of a legend, the colon must be escaped with a backslash \:. Beware that many environments process backslashes themselves, so it may be necessary to write two backslashes in order to one being passed onto rrd_graph.
The text printed below the actual graph can be formatted by appending special escape 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: \j for justified, \l for left aligned, \r for right aligned, and \c for centered. In the next section there is an example showing how to use centered formatting.
\n is a valid alias for \l since incomplete parsing in earlier versions of rrdtool lead to this behaviour and a number of people has been using it.
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 \g at the end of the string. The \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 %s to suppress empty unit strings.
A special case is COMMENT:\s which 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 \t to line-up legend elements. Note that the tabs inserted are relative to the start of the current legend element!
rrdgraph gives an overview of how rrdtool graph works. rrdgraph_data describes DEF,CDEF and VDEF in detail. rrdgraph_rpn describes the RPN language used in the ?DEF statements. rrdgraph_graph page describes all of the graph and print functions.
Make sure to read rrdgraph_examples for tips&tricks.
Program by Tobias Oetiker <firstname.lastname@example.org>
This manual page by Alex van den Bogaerdt <email@example.com>