tools/osutils/osutils.go

// Package osutils provide tools that interact with the OS or the shell.
package osutils

import (
	"bufio"
	"bytes"
	"github.com/golang/glog"
	"io"
	"os"
	"os/exec"
	"strings"
)

// Run returns the stdout and stderr the output of running the given command
// with the given arguments.
func Run(command string, args []string, hideStderr bool) (string, error) {
	cmd := exec.Command(command, args...)
	glog.Infof("running command `%s`", cmd)

	var stdout, stderr bytes.Buffer
	cmd.Stdout = &stdout
	cmd.Stderr = &stderr
	if !hideStderr {
		// Displays stderr as it comes to the os.stderr
		// Useful when running install as the executing logs
		// are displayed on the os.stderr as it runs
		cmd.Stderr = io.MultiWriter(os.Stderr, &stderr)
	}
	err := cmd.Run()
	// Discarding errors if hideStderr is true, similar to setting '2>/dev/null'.
	if hideStderr {
		return stdout.String(), nil
	}
	return stdout.String(), err
}

// Parse returns a mapping of contents of the osFile.
//
// Syntax of contents in the os realease file : <key>=<value>
// Returns a mapping of the key to value
func Parse(osFile string) (map[string]string, error) {
	f, err := os.Open(osFile)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	osReleaseFile := make(map[string]string)
	scanner := bufio.NewScanner(f)

	for scanner.Scan() {
		line := scanner.Text()
		key, value, found := strings.Cut(line, "=")
		if found {
			osReleaseFile[key] = value
		}
	}
	return osReleaseFile, nil
}