package hmpki

import (
	"os"
)

// CreateFileWith Creates a new file (fails it if already exists) with the
// given content and permissions.
func createFileWith(name string, content []byte, perms os.FileMode) error {
	f, err := os.OpenFile(
		name,
		// Write only, and fail if it alreay exists.
		os.O_WRONLY|os.O_CREATE|os.O_EXCL,
		perms,
	)
	if err != nil {
		return err
	}
	defer f.Close()
	if _, err = f.Write(content); err != nil {
		return err
	}
	return nil
}