otto-fs.go

otto-fs.go

package main

import (
    "github.com/robertkrimen/otto"
    "io/ioutil"
)

func main() {
  vm := otto.New()

  fsModuleDef := map[string]func(otto.FunctionCall) otto.Value{
    "readFileSync": func(call otto.FunctionCall) otto.Value {
      var filename string

      filename, _ = call.Argument(0).ToString()
      fileData, _ := ioutil.ReadFile(filename)

      output, _ := vm.ToValue(string(fileData))
      return output
    },
  }

  fsModule, _ := vm.ToValue(fsModuleDef)
  vm.Set("fs", fsModule)

  var script = `
  var output = fs.readFileSync('test.txt')
  console.log("File data:")
  console.log(output)
  `
  vm.Run(script)
}

test.txt

hello
world