Numbersflags: g

Octal Number Literal

Match modern ECMAScript-style octal literals (`0o755`) — strict per ES6+ syntax.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("\\b0[oO][0-7]+\\b", "g");
const input = "perms = 0o755; mask = 0o022";
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"\b0[oO][0-7]+\b")
input_text = "perms = 0o755; mask = 0o022"
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(`\b0[oO][0-7]+\b`)
	input := `perms = 0o755; mask = 0o022`
	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

\b0[oO][0-7]+\b   (flags: g)

Raw source: \b0[oO][0-7]+\b

How it works

\b is a word boundary. 0[oO] requires the modern ES6 octal prefix (case-insensitive on the o). [0-7]+ matches one or more octal digits (0–7). \b prevents matching into adjacent letters. Note: the loose `0755` form (no o) is technically a legacy octal in some languages but is dangerous in JS strict mode — this pattern requires the explicit `0o` prefix.