NodeJS - convert relative path to absolute

Question

In my File-system my working directory is here:

C:\temp\a\b\c\d

and under b\bb there's file: tmp.txt

C:\temp\a\b\bb\tmp.txt

If I want to go to this file from my working directory, I'll use this path:

"../../bb/tmp.txt"

In case the file is not exist I want to log the full path and tell the user:
"The file C:\temp\a\b\bb\tmp.txt is not exist".

My question:

I need some function that convert the relative path: "../../bb/tmp.txt" to absolute: "C:\temp\a\b\bb\tmp.txt"

In my code it should be like this:

console.log("The file" + convertToAbs("../../bb/tmp.txt") + " is not exist")

Rescissory

Answer 1

Use path.resolve

try:

resolve = require('path').resolve
resolve('../../bb/tmp.txt')

Dimphia

you can also use const {resolve} = require("path"); – Farris

@DarkKnight, Is there any way to avoid ../../../etc? – Cockahoop

@Cockahoop you can use a variable or change working directory like this: https://mcmap.net/q/89335/-change-working-directory-in-my-current-shell-context-when-running-node-script/4578017 A variable is preferred since changing working directory might cause unwanted side effects – Dimphia

with the newer esm it is import path from 'path' and then path.resolve(). – Kudu

Answer 2

You could also use __dirname and __filename for absolute path.

Mangan

Use this only to know the absolute path of the current directory in which the file resides and the current file respectively. – Suffruticose

Answer 3

If you can't use require:

const path = {
    /**
    * @method resolveRelativeFromAbsolute resolves a relative path from an absolute path
    * @param {String} relitivePath relative path
    * @param {String} absolutePath absolute path
    * @param {String} split default?= '/', the path of the filePath to be split wth 
    * @param {RegExp} replace default?= /[\/|\\]/g, the regex or string to replace the filePath's splits with 
    * @returns {String} resolved absolutePath 
    */
    resolveRelativeFromAbsolute(relitivePath, absolutePath, split = '/', replace = /[\/|\\]/g) {
        relitivePath = relitivePath.replaceAll(replace, split).split(split);
        absolutePath = absolutePath.replaceAll(replace, split).split(split);
        const numberOfBacks = relitivePath.filter(file => file === '..').length;
        return [...absolutePath.slice(0, -(numberOfBacks + 1)), ...relitivePath.filter(file => file !== '..' && file !== '.')].join(split);
    }
};

const newPath = path.resolveRelativeFromAbsolute('C:/help/hi/hello/three', '../../two/one'); //returns 'C:/help/hi/two/one'

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