Work with files/dirs

Here are notes about useful methods to work with paths, directories, and files. I keep searching for them all the time, so brief summary of what I usually need would be good.

System.IO.Path class

Works on strings that represent logical path to file or a directory. Provides many useful static methods like

• Path.GetFullPath - returns an absolute path from a relative path. Can work against both current directory or specified base path
• Path.Combine - combines number of strings into a path
• Path.Exists - checks existence of entity referenced by specified path
• Path.GetDirectoryName - gets directory portion of the path
• Path.GetFileName and Path.GetFileNameWithoutExtension - get file name from the path
• Path.GetExtension - returns file extension

System.IO.Directory class

Static methods to work on directories like copying, moving, enumerating them.

I use the Directory.EnumerateFiles very often to find files across many input directories and their subdirectories:

foreach (string file in inputDirectories.SelectMany(
    dir => Directory.EnumerateFiles(dir, "*.xls*", SearchOption.AllDirectories)))
{
    ProcessFile(file);
}

Other useful methods are EnumerateDirectories, Create, Delete, Exists, or Move.

System.IO.File class

Many tools to work with files, from Open, Exists, ReadAllLines, ReadAllText to Copy and Move.

Interesting functionality that can come handy on Windows platform that can use NTFS Encrypting File System (EFS) are methods Encrypt and Decrypt that provide protection that allow to decrypt only by same account who encrypted it.