FileManager

import Foundation

let fm = FileManager.default

// Get the URL for the Documents directory
let docsURL = fm.urls(for: .documentDirectory, in: .userDomainMask)[0]
print("Documents: \(docsURL.path)")

// Create and write a file
let fileURL = docsURL.appendingPathComponent("test.txt")
let content = "Hello, Swift FileManager!"
try? content.write(to: fileURL, atomically: true, encoding: .utf8)

// Check if the file exists
print("Exists: \(fm.fileExists(atPath: fileURL.path))")

// Read the file
if let text = try? String(contentsOf: fileURL, encoding: .utf8) {
    print("Contents: \(text)")
}

// Create a directory
let dirURL = docsURL.appendingPathComponent("MyFolder")
try? fm.createDirectory(at: dirURL, withIntermediateDirectories: true)
print("Directory created: \(fm.fileExists(atPath: dirURL.path))")

// Copy a file
let copyURL = dirURL.appendingPathComponent("copy.txt")
try? fm.copyItem(at: fileURL, to: copyURL)

// List files in a directory
if let contents = try? fm.contentsOfDirectory(at: docsURL, includingPropertiesForKeys: nil) {
    print("Contents of Documents:")
    for url in contents {
        print("  \(url.lastPathComponent)")
    }
}

// Move a file
let movedURL = docsURL.appendingPathComponent("moved.txt")
try? fm.moveItem(at: copyURL, to: movedURL)

// Delete a file
try? fm.removeItem(at: movedURL)
try? fm.removeItem(at: dirURL)
print("Exists after deletion: \(fm.fileExists(atPath: movedURL.path))")

In iOS and macOS apps, the convention is to store user data in the Documents directory and cache data in the Caches directory. You can retrieve these paths using FileManager.default.urls(for:in:).

For reading and writing files, String.write(to:) and Data.write(to:) are convenient options. Use FileManager for larger files or more complex operations. Always handle file operation errors with try-catch. Operations may temporarily fail depending on the iCloud Drive sync state.

For persisting small amounts of data with UserDefaults, see UserDefaults.