Relative Path

const re = new RegExp("^(\\.{1,2}\\/)?([^\\/\\0]+\\/)*[^\\/\\0]+$", "");
const input = "./src/index.ts";
const match = input.match(re);
console.log(match ? match[0] : null);

import re

pattern = re.compile(r"^(\.{1,2}\/)?([^\/\0]+\/)*[^\/\0]+$")
input_text = "./src/index.ts"
for m in pattern.finditer(input_text):
    print(m.group(0))

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`^(\.{1,2}\/)?([^\/\0]+\/)*[^\/\0]+$`)
	input := `./src/index.ts`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}