File & Path

Windows File Path

Matches absolute Windows file paths (e.g., C:\Users\file.txt).

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("^[A-Za-z]:\\\\(?:[^\\\\/:*?\"<>|\\r\\n]+\\\\)*[^\\\\/:*?\"<>|\\r\\n]*$", "");
const input = "C:\\Users\\John\\file.txt";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"^[A-Za-z]:\\\\(?:[^\\\\/:*?\"<>|\\r\\n]+\\\\)*[^\\\\/:*?\"<>|\\r\\n]*$")
input_text = "C:\Users\John\file.txt"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`^[A-Za-z]:\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$`)
	input := `C:\Users\John\file.txt`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

^[A-Za-z]:\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$

Raw source: ^[A-Za-z]:\$?:[^\\/:*?"<>|\r\n]+\$*[^\\/:*?"<>|\r\n]*$

How it works

`^[A-Za-z]:\\` matches the drive letter and root backslash. `(?:[^\\/:*?"<>|\r\n]+\\)*` matches directory segments. Final segment (the file or folder name) is allowed to be empty.