MSBuild task: FindFilesInList

FindFilesInList.cs

using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
using System.Collections.Generic;
using System.IO;
using System.Linq;

public class FindFilesInList : Task
{
    [Required]
    public ITaskItem[] Items { get; set; }

    [Required]
    public ITaskItem[] ItemsToFind { get; set; }

    [Output]
    public ITaskItem[] FoundItems { get; set; }

    public override bool Execute()
    {
        ICollection<string> pathsToFind = ItemsToFind.Select(taskItem => new FileInfo(taskItem.ItemSpec).FullName).ToList();
        ICollection<ITaskItem> foundItemsList = new List<ITaskItem>();
        foreach (ITaskItem item in Items)
        {
            FileInfo file = new FileInfo(item.ItemSpec);
            if (pathsToFind.Contains(file.FullName))
            {
                foundItemsList.Add(item);
            }
        }
        FoundItems = foundItemsList.ToArray();
        return true;
    }
}