check if file exists (case-sensitive)

Question

Is there a way to check whether a file exists in NodeJS, with case-sensitivity, even when the underlying file system isn't case sensitive?

fs.exists() may or may not be case sensitive depending on the underlying file system.

 fs = require('fs');
 fs.existsSync('readme.txt') // true
 fs.existsSync('README.TXT') // false (or true, depending on the file system)

This causes problems when developing an app on a case-insensitive development environment that will be deployed on a case-sensitive server. I recently had an issue where the build was broken by a typo. It worked locally.

If I can get Node to tell me, "yes, README.TXT exists, and it's stored as readme.txt" that will be enough to solve the problem.

I think a http://nodejs.org/api/fs.html#fs_fs_realpathsync_path_cache would do the trick (though you'd likely want to try catch wrap it since it can throw) — generalhenry, Dec 08 '14 at 21:43
you could try to do readdir first - afaik on osx it returns names in original case — Andrey Sidorov, Dec 08 '14 at 21:51
@generalhenry Good thought. Unfortunately it returns the same case as the input. — Patrick McElhaney, Dec 08 '14 at 21:52

score 6 · Answer 1 · edited May 23 '17 at 11:54

Following Andrey's suggestion I implemented a function that uses readdir.

var fs = require('fs');
var path = require('path');

function fileExistsWithCaseSync(filepath) {
    var dir = path.dirname(filepath);
    if (dir === '/' || dir === '.') return true;
    var filenames = fs.readdirSync(dir);
    if (filenames.indexOf(path.basename(filepath)) === -1) {
        return false;
    }
    return fileExistsWithCaseSync(dir);
}

console.log(fileExistsWithCaseSync(__dirname + '/README.txt')) // false
console.log(fileExistsWithCaseSync(__dirname + '/readme.txt')) // true

I wouldn't use this function in production because each call makes several synchronous trips to the filesystem. But it's good enough for my needs: preventing my local development server from serving Foo.js when the file is actually called foo.js (which won't work in production).

score 2 · Answer 2 · answered Oct 20 '18 at 17:38

2

Just to help someone who having this path problem.

The Patric's function pretty works for this case, but not solve the path issue. I found the true path module that actually solved my problem with case-sensitive paths on linux (ubuntu).

See more info here.

answered Oct 20 '18 at 17:38

Luiz Fernando da Silva

1,409
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21

score 2 · Accepted Answer · edited Jan 04 '19 at 15:20

Since I can't comment < 50 rep I'll make a new post.

@patrik's solution was working nice except on windows because of the root check

I changed it to look like following:

function fileExistsWithCaseSync (filepath) {
  var dir = path.dirname(filepath)
  if (dir === path.dirname(dir)) {
    return true
  }
  var filenames = fs.readdirSync(dir)
  if (filenames.indexOf(path.basename(filepath)) === -1) {
    return false
  }
  return fileExistsWithCaseSync(dir)
}

score 0 · Answer 4 · answered Apr 24 '22 at 03:44

var fs = require('fs');
var path = require('path');

function fileExistsWithCaseSync(filepath) {
    var dir = path.dirname(filepath);
    if (filepath=== '/' || filepath=== '.') return true;
    var filenames = fs.readdirSync(dir);
    if (filenames.indexOf(path.basename(filepath)) === -1) {
        return false;
    }
    return fileExistsWithCaseSync(dir);
}

console.log(fileExistsWithCaseSync('./README.txt')) // false
console.log(fileExistsWithCaseSync('./readme.txt')) // true

check filepath use fileExistsWithCaseSync no __dirname

check if file exists (case-sensitive)

4 Answers4