Seeking a position within a file

In some cases, you need to read from or write to a particular location in a file, such as an indexed file. The recipe will show you how to use the position seeking in the context of flat file operations.

How to do it...

1. Open the console and create the folder chapter05/recipe06.
2. Navigate to the directory.

3. Create the file flatfile.txt with the following content:

      123.Jun.......Wong......
      12..Novak.....Jurgen....
      10..Thomas....Sohlich...

4. Create the fileseek.go file with the following content:

        package main

        import (
          "errors"
          "fmt"
          "os"
        )

        const lineLegth = 25

        func main() {

          f, e := os.OpenFile("flatfile.txt", os.O_RDWR|os.O_CREATE,
                              os.ModePerm)
          if e != nil {
            panic(e)
          }
          defer f.Close()

          fmt.Println(readRecords(2, "last", f))
          if err := writeRecord(2, "first", "Radomir", f); err !=...