child_process.spawn() requires "/" but path.resolve() returns "\" on windows

[SpikedKira]

ERRORS:
var mypath = path.resolve('node_modules', 'package', 'scriptName.cmd');
var cp = child_process.spawn(mypath, args);

WORKS:
var mypath = path.resolve('node_modules', 'package', 'scriptName.cmd');
mypath = mypath.replace(//g, '/');
var cp = child_process.spawn(mypath, args);

[bricss]

FYI -> https://nodejs.org/api/path.html#path_path_normalize_p

[jhamhader]

What error does it produce?

[SpikedKira]

oh man, i didn't document the error, but if I recall, spawn() tried to digest the path up to the first "" and dropped the rest which resulted in a path not found or similar

[dotnetCarpenter]

I'm investigating a very similar case where spawn throws Error: spawn UNKNOWN when getting a path from require.resolve().

E.i: t1.js

require("child_process").spawn( require.resolve("./t2") )

t2.js

#!/usr/bin/env node
console.log("Hello World");

path.normalize does not make any difference. This is a Windows only issue which makes me think that spawn behaves very differently on Windows.

[dotnetCarpenter]

After reading the an old issue in node 0.6 I figure that the shebang I use saved me on mac and linux but became an issue on windows. The work around for Windows's missing shebang support is add path as a arguments to nodejs.

require("child_process").spawn( process.execPath, [require.resolve("./t2")] )

[cjihrig]

@dotnetCarpenter if you use the latest code from master, you can do:

'use strict';
const cp = require('child_process');
const file = require.resolve('./foo');
const child = cp.spawn(file, {shell: true});

child.stdout.setEncoding('utf8');
child.stdout.on('data', console.log);

I tested this on Windows 7 and OS X. Node handles the shebang for you on all platforms. The only catch is that on Windows, the .js extension must be associated with Node, and on other operating systems the file must have executable permissions.

[dotnetCarpenter]

The only catch is that on Windows, the .js extension must be associated with Node, and on other operating systems the file must have executable permissions.
...
Next you need to tell Windows to use node.exe instead of wscript.exe (Anyone still use that?) You'll need a CMD.exe window with Administrator privileges. Easy way to do that is to tap the 'Windows' key, type in CMD, right click when it appears in the menu and click 'Run as Administrator'. You may need a password.

@cjihrig well, that gotcha makes nodejs code unportable.
To be able to run nodejs crossplatform we really need the following to work consistently on OS X, linux and Windows:

'use strict';
const cp = require('child_process');
const file = require.resolve('./foo');
const child = cp.spawn(file, {nodejs: true}); // tell child_process this is a nodejs executable

child.stdout.setEncoding('utf8');
child.stdout.on('data', console.log);

Please reopen.

[bnoordhuis]

@dotnetCarpenter cp.spawn(process.execPath, [file])? I don't see why you'd need anything more.

[dotnetCarpenter]

@bnoordhuis You're completly right. I somehow forgot that.