Function Scripts

Apart from standard scripts, jko allows the execution of functions defined in JavaScript files.

Run a Function Script

Given the following jko.js:

  export default {
    scripts: {
      functionScript: function () {
        // do something
      }
    }
  }

$ jko functionScript

functionScript will be executed.

tip

When scripts are listed, no useful description is displayed beyond the default "Function" label.

$ jko
scripts:
  functionScript: Function

Use the $comment directive to add a descriptive comment.

e.g.

  export default {
    scripts: {
      functionScript: function (param1, paramN) {
        // do something
      }
      '$comment (functionScript)': 'This function script that ...'
    }
  }

$ jko
scripts:
  functionScript: Function
    This function script that ...

Run a Function Script with Arguments

Given the following jko.js:

  export default {
    scripts: {
      functionScript: function (param1, paramN) {
        // do something
      }
    }
  }

$ jko functionScript arg1 argN

jko will run functionScript with arg1 and argN as arguments to the function; that is, param1 will receive the value of arg1 and paramN will receive the value of argN.

For example:

  export default {
    scripts: {
      functionScript: function (param1, paramN) {
        const a = parseFloat(param1)
        const b = parseFloat(paramN)
        console.log(`${a} + ${b} = ${a + b}`)
      }
    }
  }

$ jko functionScript 1 2
$ 1 + 2 = 3

(Actually, the output will be longer, but it has been simplified to emphasize functionality over presentation. To get the exact same output as in the example, use the following command: jko -l=e functionScript 1 2)

Additionally, jko will set an environment variable for every argument passed in the command line, each named jko_arg_# and accessible in the function code through process.env.jko_arg_#.

For example:

  export default {
    scripts: {
      functionScript: function () {
        const a = parseFloat(process.env.jko_arg_0)
        const b = parseFloat(process.env.jko_arg_1)
        console.log(`${a} + ${b} = ${a + b}`)
      }
    }
  }

$ jko functionScript 1 2
$ 1 + 2 = 3

info

jko will create an environment variable for each argument passed in the command line, named jko_arg_#, where # starts at 0.
For example, jko_arg_0 will contain the value of the first argument, and jko_arg_N_1 will contain the value of the last argument.
arg1 saved in jko_arg_0
arg2 saved in jko_arg_1
arg3 saved in jko_arg_2
...and so on.

Run a Function Script​

Run a Function Script with Arguments​

Run a Function Script

Run a Function Script with Arguments