FileLineReader.swift

import Darwin

class FileLineReader {
    init?(path: String, removeNewLineOnEnd: Bool = true) {
        file = fopen(path, "r")
        self.removeNewLineOnEnd = removeNewLineOnEnd
        if file == nil {
            return nil
        }
    }
    
    deinit {
        fclose(file)
    }
    
    var iterator: AnyIterator<String> {
      return AnyIterator(self.getNextLine)
    }

    func getNextLine() -> String? {
        var line: UnsafeMutablePointer<CChar>!
        var linecap: Int = 0
        defer { free(line) }
        if getline(&line, &linecap, file) > 0 {
            if removeNewLineOnEnd {
                var i = 0
                while line[i] != 0 { i += 1 }
                if i > 0 && line[i-1] == 10 {
                    line[i-1] = 0
                }
            }
            return String(cString: line)
        } else {
            return nil
        }
    }
    
    private let file: UnsafeMutablePointer<FILE>!
    private let removeNewLineOnEnd: Bool
}