Table of Contents

Overview

Below go package can be used to extract URL from a given string

https://github.com/mvdan/xurls

There are two ways of using this package

Strict – In strict mode, it matches only URLs with a scheme

Relaxed – In relaxed mode, it matches any URL matched by strict plus any URLs without a scheme

You can specify the scheme to filter on. There is a function for that

StrictMatchingScheme

Program

Let’s first see a program

package main
import (
"fmt"
"mvdan.cc/xurls/v2"
)
func main() {
xurlsStrict := xurls.Strict()
output := xurlsStrict.FindAllString("golangbyexample.com is ", -1)
fmt.Println(output)
xurlsRelaxed := xurls.Relaxed()
output = xurlsRelaxed.FindAllString("The website is golangbyexample.com", -1)
fmt.Println(output)
output = xurlsRelaxed.FindAllString("golangbyexample.com is ", -1)
fmt.Println(output)
}

Output

[]
[golangbyexample.com]
[golangbyexample.com ]

Notice in the strict mode, it does not return the golangbyexample.com in the output as that is without a scheme.

Let’s see another program to extract multiple URLs

package main
import (
"fmt"
"mvdan.cc/xurls/v2"
)
func main() {
xurlsStrict := xurls.Strict()
input := "The webiste is :8000/tutorials/intro amd mail to mailto:[email protected]"
output := xurlsStrict.FindAllString(input, -1)
fmt.Println(output)
}

Output

[:8000/tutorials/intro mailto:[email protected]]

If we want to restrict the output to a particular scheme then that also can be done.

package main
import (
"fmt"
"log"
"mvdan.cc/xurls/v2"
)
func main() {
xurlsStrict, err := xurls.StrictMatchingScheme("https")
if err != nil {
log.Fatalf("Some error occured. Error: %s", err)
}
input := "The webiste is :8000/tutorials/intro amd mail to mailto:[email protected]"
output := xurlsStrict.FindAllString(input, -1)
fmt.Println(output)
}

Output

[:8000/tutorials/intro]

In the above program, we provided the scheme as https which is why we have only one output

golang