utils.go

package main

import (
	"fmt"
	"io/ioutil"
	"strings"
)

// int8SliceToString convert and concatenate a []int8 slice to a string
// inspired by perterGo: https://groups.google.com/forum/#!topic/golang-nuts/Jel8Bb-YwX8
func int8SliceToString(char []int8) string {
	s := make([]string, len(char))
	for i := range s {
		s[i] = string(char[i])
	}
	return strings.Join(s, "")
	// TODO maybe change this to convert exclusively to [65]int8 array ?
}

// readAndTrimFile read a text file and return the content without the EOF carriage return
// this utility may be used with files from `/sys` or `/proc` file systems
var readAndTrimFile = func(path string) (ret string, err error) {
	ret = ""
	data, err := ioutilReadFile(path)
	if err == nil {
		ret = strings.TrimRight(string(data), "\n") // Trimright remove the EOF carriage return
	}
	return ret, err
	//TODO manage multiple line files ?
}

// appendError() combines two errors into one
func appendError(err1 error, err2 error) (err error) {
	switch {
	case err1 != nil && err2 != nil:
		err = fmt.Errorf("%v; %v", err1, err2)
	case err1 != nil:
		err = err1
	case err2 != nil:
		err = err2
	case err1 == nil && err2 == nil:
		err = nil
	}

	return err
}

// wrap `ioutil.ReadFile` in an unexported variable for testability
var ioutilReadFile = func(filename string) ([]byte, error) {
	return ioutil.ReadFile(filename)
}