# Indicator: ExScript: External Script

The "ExScript" indicator passes data to an external program and then plots the output that is returned.

See the example CUS indicator at `misc/CUS_examples/Contributions/xley/ExScript`

Copy the companion Perl program ExScript.pl to somewhere in your home directory. Now edit the indicator example to refer to that pathname.

    # That example indicator outputs just the "date,volume" for each bar, as well
    # as the commandline argument scaleFactor, and calls this Perl script.
    # The script calculates the average of all bars, gets the difference
    # from average and scales it. The script then passes the data back to the
    # indicator which plots it as a "Histogram Bar". It is a silly example which
    # could be done directly as a CUS script, but it gives an idea of the power.
    #
    # For example, it could also be enhanced to access the xml summary which
    # is exported using the "Tools => IndicatorSummary".

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