package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?i)((?:(?:https?|ftp):\/{2})(?:(?:[0-9a-z_@-]+\.)+(?:[0-9a-z]){2,4})?(?:(?:\/(?:[~0-9a-z\#\+\%\@\.\/_-]+))?\/)*(?=\s|\"))(\/)?(index\.html?)?`)
var str = `there is some text with <a href=" http://www.Something.com/ "> but without index.html; then there is another one that is <a href = "https://www.other.com/more/stuff/index.html"> which should be unaltered.
Finally does it work for href = "http://www.com/stuff/"
http://www.index.com/
http://ex.com/a/b/"
http://www.example.com add /index.html
http://www.example.com/something do nothing
http://www.example.com/something/ add /index.html
http://www.example.com/something/index.html do nothing
`
var substitution = "\1/index.html"
fmt.Println(re.ReplaceAllString(str, substitution))
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/