How to create a new file with the given name if the file exists

eg : if word_destination.txt exists copy content to word_destination(1).txt

Any help would be appreciated...

package main

import (
    "fmt"
    "io/ioutil"
    "os"
)


func main() {

    src := ./word_source.txt
    desti := ./folder/word_destination.txt

    //if file exists want to copy it to the word_destination(1).txt
    if _, err := os.Stat(desti); err == nil {
        // path/to/whatever exists
        fmt.Println("File Exists")

    } else {
        fmt.Println("File does not Exists")
        bytesRead, err := ioutil.ReadFile(src)

        if err != nil {
            log.Fatal(err)
        }

CodePudding user response：

func tryCopy(src, dst string) error {
    in, err := os.Open(src)
    if err != nil {
        return err
    }
    defer in.Close()

    out, err := os.OpenFile(dst, os.O_CREATE| os.O_EXCL, 0644)
    if err != nil {
        return err
    }
    defer out.Close()

    _, err = io.Copy(out, in)
    if err != nil {
        return err
    }
    return out.Close()
}
// ......
if _, err := os.Stat(desti); err == nil {
    // path/to/whatever exists
    fmt.Println("File Exists")
    for i := 1; ; i   {
        ext := filepath.Ext(desti)
        newpath := fmt.Sprintf("%s(%d)%s", strings.TrimSuffix(desti, ext), i, ext)

        err := tryCopy(desti, newpath)
        if err == nil {
            break;
        }
        
        if os.IsExists(err) {
            continue;
        } else {
            return err;
        }
    }
}