No output to error file - go

Question

I'm coding a little Go program.
It reads files in a directory line by line, it only reads lines with a certain prefix, normalizes the data and outputs to one of two files, depending on whether the normalized record has certain number of elements.
Data is being outputted to the Data file, but errors are not being outputted to the Errors file.
Debugging I see no issue.
Any help is much appreciated.
Thanks,
Martin
package main
import (
"bufio"
"fmt"
"io/ioutil"
"log"
"os"
"strings"
)
func main() {
//Output file - Data
if _, err := os.Stat("allData.txt"); os.IsNotExist(err) {
var file, err = os.Create("allData.txt")
if err != nil {
fmt.Println(err)
return
}
defer file.Close()
}
file, err := os.OpenFile("allData.txt", os.O_WRONLY|os.O_APPEND, 0644)
if err != nil {
panic(err)
}
w := bufio.NewWriter(file)
//Output file - Errors
if _, err := os.Stat("errorData.txt"); os.IsNotExist(err) {
var fileError, err = os.Create("errorData.txt")
if err != nil {
fmt.Println(err)
return
}
defer fileError.Close()
}
fileError, err := os.OpenFile("errorData.txt", os.O_WRONLY|os.O_APPEND, 0644)
if err != nil {
panic(err)
}
z := bufio.NewWriter(fileError)
//Read Directory
files, err := ioutil.ReadDir("../")
if err != nil {
log.Fatal(err)
}
//Build file path
for _, f := range files {
fName := string(f.Name())
sPath := string("../" + fName)
sFile, err := os.Open(sPath)
if err != nil {
fmt.Println(err)
return
}
//Create scanner
scanner := bufio.NewScanner(sFile)
scanner.Split(bufio.ScanLines)
var lines []string
// This is the buffer now
for scanner.Scan() {
lines = append(lines, scanner.Text())
}
for _, line := range lines {
sRecordC := strings.HasPrefix((line), "DATA:")
if sRecordC {
splitted := strings.Split(line, " ")
splittedNoSpaces := deleteEmpty(splitted)
if len(splittedNoSpaces) == 11 {
splittedString := strings.Join(splittedNoSpaces, " ")
sFinalRecord := string(splittedString + "\r\n")
if _, err = fmt.Fprintf(w, sFinalRecord); err != nil {
}
}
if len(splittedNoSpaces) < 11 {
splitted := strings.Split(line, " ")
splittedNoSpaces := deleteEmpty(splitted)
splittedString := strings.Join(splittedNoSpaces, " ")
sFinalRecord := string(splittedString + "\r\n")
if _, err = fmt.Fprintf(z, sFinalRecord); err != nil {
}
err = fileError.Sync()
if err != nil {
log.Fatal(err)
}
}
}
}
}
err = file.Sync()
if err != nil {
log.Fatal(err)
}
}
//Delete Empty array elements
func deleteEmpty(s []string) []string {
var r []string
for _, str := range s {
if str != "" {
r = append(r, str)
}
}
return r
}

Answer 1

Don't open the file multiple times, and don't check for the file's existence before creating it, just use the os.O_CREATE flag. You're also not deferring the correct os.File.Close call, because it's opened multiple times.
When using a bufio.Writer, you should always call Flush() to ensure that all data has been written to the underlying io.Writer.