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FRIDA: External curves

This page is part of the Frida online manual.

Usually, fit curves are constructed using built-in functions. However, it is also possible to create a curve that is computed through an external computer program.

The command

> cca h

gives up-to date information on the different ways to construct an external curve.

At present, the codes

ecr, eir, ecw, eiw

can be used to set external evaluation mode. Frida then prompts for the name of the external program and for the number of parameters.

The above codes bear the following meanings:

  • c: The external program reads parameters from the command line.
  • i: The external program reads parameters from stdin; the first input line must contain the number of parameters (for redundant cross-check); the following lines contain one parameter each.
  • r: The external program reads x values from stdin (after reading parameters, if applicable); it first expects one line containing the number of x values; each of the following lines contains one x value.
  • w: The external program sets its own x grid; Frida then interpolates.

In any case, the external program outputs lines containing data pairs x y.