FileDescriptor

Example: Open and read an ASCII file

import SwiftIO

// Open the file located in "/subDir/hello.txt"
if let file = try? FileDescriptor.open("/SD:/subDir/hello.txt") {
    //Initialize a buffer to store the reading bytes.
    var buffer = UnsafeMutableRawBufferPointer.allocate(byteCount: 10, alignment: 4)

    do {
        // Read bytes into the buffer
        try file.read(into: buffer)

        // Print the reding bytes.
        for i in 0..<buffer.count {
            print(buffer[i])
        }
    } catch {
        print("Unexpected error: \(error).")
    }
}

while true {
   sleep(ms: 1000)
}

Opening a File

• static func open(String, FileDescriptor.AccessMode, options: FileDescriptor.OpenOptions) throws

  Open or creates, if does not exist, file.

• struct AccessMode

  The desired read and write access for a newly opened file.

• struct OpenOptions

  Options that specify behavior for a newly-opened file.

Reading from a file

• read(into:count:)-1e6cm
• read(into:count:)-3x3lj
• read(fromAbsoluteOffest:into:count:)-6abp2
• read(fromAbsoluteOffest:into:count:)-k2ts

Writing to a file

• func write(String) throws

  Writes the contents of a string at the current file offset.

• write(_:count:)-8l97n
• write(_:count:)-2p42a
• write(toAbsoluteOffset:_:count:)-42r4g
• write(toAbsoluteOffset:_:count:)-7r2v8

Closing a File

• func close() throws

  Flushes the associated stream and closes the file.

Changing a File’s Offset

• func seek(offset: Int, from: SeekOrigin) throws

  Repositions the offset for the given file descriptor.

• struct SeekOrigin

  Options for specifying what a file descriptor’s offset is relative to.