Is there a way to save the obtained output from a a process object's getOutPutStream() method into a file

public interface IFrontEndEntity<TEntity>
{
    TEntity GetEntity();
}
public static class FrontEndExtensions
{
    public static IEnumerable<TEntity> GetEntities<TEntity>(this IEnumerable<IFrontEndEntity<TEntity>> frontEndItems)
    {
        return frontEndItems.Select(a => a.GetEntity());
    }
}
public class Dog
{
}
public class DogFrontEnd : IFrontEndEntity<Dog>
{
    public Dog Entity { get; set; }
    public Dog GetEntity()
    {
        return Entity;
    }
}
public class Main
{
    public void Run()
    {
        IEnumerable<DogFrontEnd> dogFronEnds = new List<DogFrontEnd>();
        IEnumerable<Dog> dogs = dogFronEnds.GetEntities();
    }
}

test<-function(x){
a<-x+4
b<-x/34
return(c(a,b))
}
list<-c(3,4,5,6,6)
lapply(list,test)