package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)^<img src="index-(?![12]_)(\d+)_\d+\.(?:jpg|png)"\/><br>$`)
var str = `<img src="index-1_2.jpg"/><br>
<img src="index-1_3.jpg"/><br>
<img src="index-1_5.jpg"/><br>
<img src="index-2_1.jpg"/><br>
<img src="index-2_5.jpg"/><br>
<img src="index-3_1.png"/><br>
<img src="index-23_8.png"/><br>
<img src="index-22_9.png"/><br>
<img src="index-22_1.jpg"/><br>
<img src="index-22_2.jpg"/><br>
<img src="index-99_5.png"/><br>
<img src="index-100_5.png"/><br>
<img src="index-1000_5.png"/><br>`
var substitution = "$1"
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/