Cross-platform file reader in Swift

read_file.swift

// Latest snapshot, 01-11-2016, seems to have fixed the missing SEEK_END pointer yet
// made NSData(contentsOfFile:) a missing symbol on Linux

func contents(path: String) -> String? {
    let fp: UnsafeMutablePointer<FILE> = fopen(path, "r")
    defer { fclose(fp) }

    fseek(fp, 0, SEEK_END)
    let fileSize = ftell(fp)
    rewind(fp)

    var buffer = UnsafeMutablePointer<CChar>.alloc(fileSize+1)
    defer { buffer.destroy() }

    fread(buffer, sizeof(CChar), fileSize, fp)
    buffer[fileSize] = 0

    guard let str = String.fromCString(buffer) else {
        return nil
    }

    return str
}