如何从行中删除

file, _ := os.Open("x.txt")
    f := bufio.NewReader(file)

    for {
        read_line, _ := ReadString('
')
        fmt.Print(read_line)


        // other code what work with parsed line...
        }

end it add on every line , end program to work , only work with last line...

Please put example, i try anything end any solution what i find here not work for me.

You can slice off the last character:

read_line = read_line[:len(read_line)-1]

Perhaps a better approach is to use the strings library:

read_line = strings.TrimSuffix(read_line, "
")

If you want to read a file line-by-line, using bufio.Scanner will be easier. Scanner won't includes endline ( or ) into the line.

file, err := os.Open("yourfile.txt")
if err != nil {
    //handle error
    return
}
defer file.Close()

s := bufio.NewScanner(file)
for s.Scan() {
    read_line := s.Text()

    // other code what work with parsed line...
}

If you want to remove endline, I suggest you to use TrimRightFunc, i.e.

read_line = strings.TrimRightFunc(read_line, func(c rune) bool {
    //In windows newline is 

    return c == '' || c == '
'
})

Update:
As pointed by @GwynethLlewelyn, using TrimRight will be simpler (cleaner), i.e.

 read_line = strings.TrimRight(read_line, "
")

Internally, TrimRight function call TrimRightFunc, and will remove the character if it match any character given as the second argument of TrimRight.