The images in the Gallery would be a lot more useful if they were complemented by the source code. Man pages are nice, but a couple of simple to complex examples (in cut & paste style) are even nicer.

Here is one example:

RRDs::graph($pic_name,
    # Title of the graph, it is displayed on top of the image
    "--title", "$server CPU Load",
    # Defining colors for the basic graph objects
    "--color", "BACK#000000",
    "--color", "SHADEA#000000",
    "--color", "SHADEB#000000",
    "--color", "FONT#DDDDDD",
    "--color", "CANVAS#202020",
    "--color", "GRID#666666",
    "--color", "MGRID#AAAAAA",
    "--color", "FRAME#202020",
    "--color", "ARROW#FFFFFF",
    # limiting the graph to only 17 load
    "-u 17", "-r",
    # defining data segments for today's and yesterday's load
    "DEF:today=$rrd_name:cpuLoad:AVERAGE:start=end-86400:end=now",
    "DEF:yesterday=$rrd_name:cpuLoad:AVERAGE:start=end-86400:end=now-86400",
    # combining both data segments on one GRAPH
    # if we don't shift yesterday, it will not appear on the graph 
    # since it's time frame is not the one that is currently viewed
    "SHIFT:yesterday:86400",
    # Generate averages for both days
    "CDEF:avg=PREV,UN,today,UN,UNKN,today,IF,PREV,IF,today,UN,1,today,IF,-,0.97,*,today,UN,1,today,IF,+",
    "CDEF:avg1=PREV,UN,yesterday,UN,UNKN,yesterday,IF,PREV,IF,yesterday,UN,1,yesterday,IF,-,0.97,*,yesterday,UN,1,yesterday,IF,+",
    # Write the average of today as a line
    "LINE1:avg#0000FF:Today avg\\t\\t",

    "CDEF:shading2=today,0.98,*", "AREA:shading2#F90000:Today\\t",
    "CDEF:shading10=today,0.90,*", "AREA:shading10#E10000",
    "CDEF:shading15=today,0.85,*", "AREA:shading15#D20000",
    "CDEF:shading20=today,0.80,*", "AREA:shading20#C30000",
    "CDEF:shading25=today,0.75,*", "AREA:shading25#B40000",
    "CDEF:shading30=today,0.70,*", "AREA:shading30#A50000",
    "CDEF:shading35=today,0.65,*", "AREA:shading35#960000",
    "CDEF:shading40=today,0.60,*", "AREA:shading40#870000",
    "CDEF:shading45=today,0.55,*", "AREA:shading45#780000",
    "CDEF:shading50=today,0.50,*", "AREA:shading50#690000",
    "CDEF:shading55=today,0.45,*", "AREA:shading55#5A0000",
    "CDEF:shading60=today,0.40,*", "AREA:shading60#4B0000",
    "CDEF:shading65=today,0.35,*", "AREA:shading65#3C0000",
    "CDEF:shading70=today,0.30,*", "AREA:shading70#2D0000",
    "CDEF:shading75=today,0.25,*", "AREA:shading75#180000",
    "CDEF:shading80=today,0.20,*", "AREA:shading80#0F0000",
    "CDEF:shading85=today,0.15,*", "AREA:shading85#000000",
    #
    "GPRINT:today:MAX:Max load\\\: %.2lf",
    "GPRINT:today:AVERAGE:LoadAvg\\\: %.2lf\\n",
    "LINE1:avg1#00FFFF:Yesterday avg\\t",
    "CDEF:shadin2=yesterday,0.98,*", "AREA:shadin2#ffa946:Yesterday\\t",
    "CDEF:shadin10=yesterday,0.90,*", "AREA:shadin10#ffa946",
    "CDEF:shadin15=yesterday,0.85,*", "AREA:shadin15#e1953e",
    "CDEF:shadin20=yesterday,0.80,*", "AREA:shadin20#d28b3a",
    "CDEF:shadin25=yesterday,0.75,*", "AREA:shadin25#c38136",
    "CDEF:shadin30=yesterday,0.70,*", "AREA:shadin30#b47731",
    "CDEF:shadin35=yesterday,0.65,*", "AREA:shadin35#a56d2d",
    "CDEF:shadin40=yesterday,0.60,*", "AREA:shadin40#966329",
    "CDEF:shadin45=yesterday,0.55,*", "AREA:shadin45#875925",
    "CDEF:shadin50=yesterday,0.50,*", "AREA:shadin50#785021",
    "CDEF:shadin55=yesterday,0.45,*", "AREA:shadin55#69461d",
    "CDEF:shadin60=yesterday,0.40,*", "AREA:shadin60#5a3c19",
    "CDEF:shadin65=yesterday,0.35,*", "AREA:shadin65#4b3215",
    "CDEF:shadin70=yesterday,0.30,*", "AREA:shadin70#3c2810",
    "CDEF:shadin75=yesterday,0.25,*", "AREA:shadin75#2d1e0c",
    "CDEF:shadin80=yesterday,0.20,*", "AREA:shadin80#1e1408",
    "CDEF:shadin85=yesterday,0.15,*", "AREA:shadin85#0f0a04",
    "GPRINT:yesterday:MAX:Max load\\\: %.2lf",
    "GPRINT:yesterday:AVERAGE:LoadAvg\\\: %.2lf\\n"
);

Marian Marinov <mm |AT| yuhu.biz>