File read works in playground but fails in MacOS app

Code Block 
import Cocoa
var path = "/Users/jeff/Documents/DateDisplayData.txt"
//read text file line by line
func readFile(_ path: String) -> Int {
    errno = 0
    if freopen(path, "r", stdin) == nil {
        perror(path)
        return 1
    }
    while let line = readLine() {
        //do something with lines..
        print(line)
    }
    return 0
}
readFile(path)

Code Block 
import Cocoa
// get URL to the the documents directory in the sandbox
let home = FileManager.default.homeDirectoryForCurrentUser
// add a filename
let fileUrl = home
    .appendingPathComponent("Documents")
    .appendingPathComponent("DateDisplayData")
    .appendingPathExtension("txt")
// make sure the file exists
guard FileManager.default.fileExists(atPath: fileUrl.path) else {
    preconditionFailure("file expected at \(fileUrl.absoluteString) is missing")
}
// open the file for reading
// note: user should be prompted the first time to allow reading from this location
guard let filePointer:UnsafeMutablePointer<FILE> = fopen(fileUrl.path,"r") else {
    preconditionFailure("Could not open file at \(fileUrl.absoluteString)")
}
// a pointer to a null-terminated, UTF-8 encoded sequence of bytes
var lineByteArrayPointer: UnsafeMutablePointer<CChar>? = nil
// the smallest multiple of 16 that will fit the byte array for this line
var lineCap: Int = 0
// initial iteration
var bytesRead = getline(&lineByteArrayPointer, &lineCap, filePointer)
defer {
    // remember to close the file when done
    fclose(filePointer)
}
while (bytesRead > 0) {
    // note: this translates the sequence of bytes to a string using UTF-8 interpretation
    let lineAsString = String.init(cString:lineByteArrayPointer!)
    // do whatever you need to do with this single line of text
    print(lineAsString, terminator: "")
    // updates number of bytes read, for the next iteration
    bytesRead = getline(&lineByteArrayPointer, &lineCap, filePointer)
}