program only prints last string of input file - io

Question

i am trying to create a simple program to read lines from a text file and print them out to the console in golang. I spent lots of time going over my code and I simply can't understand why only the last line is being printed out to the screen. can anyone tell me where I am going wrong here? Everything here should compile and run.
package main
import (
"bufio"
"fmt"
"os"
)
func Readln(r *bufio.Reader) (string, error) {
var (
isPrefix bool = true
err error = nil
line, ln []byte
)
for isPrefix && err == nil {
line, isPrefix, err = r.ReadLine()
ln = append(ln, line...)
}
return string(ln), err
}
func main() {
f, err := os.Open("tickers.txt")
if err != nil {
fmt.Printf("error opening file: %v\n", err)
os.Exit(1)
}
r := bufio.NewReader(f)
s, e := Readln(r)
for e == nil {
fmt.Println(s)
s, e = Readln(r)
}
}

Answer 1

I therefore suspect that the problem is in your tickers.txt file line endings. The docs for ReadLine() also indicate that for most situations a Scanner is more suitable.
The following SO question has some useful information for alternative implementations: reading file line by line in go
I then used the example in the above question to re-implement your main function as follows:
f, err := os.Open("tickers.txt")
if err != nil {
fmt.Printf("error opening file: %v\n", err)
os.Exit(1)
}
scanner := bufio.NewScanner(f)
for scanner.Scan() {
fmt.Println(scanner.Text())
}
if err := scanner.Err(); err != nil {
fmt.Println(err)
}