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digitalmars.D.learn - Cannot spawn process: npm start

reply Andre Pany <andre s-e-a-p.de> writes:
Hi,

I need to call a Node application. node and npm are in windows 
path variable.
I have following folder structure:
./app.d
./js/helloworld.js
./js/package.json

content of helloworld.js:
console.log('hello world');

content of package.json:
{
   "name": "test",
   "version": "1.0.0",
   "scripts": {
     "start": "node helloworld.js"
   }
}

content of app.d
import std.process, std.path, std.file, std.stdio;

void main()
{
   string workDir = buildPath(thisExePath.dirName, "js");
   string[] args = ["npm", "start"];
   spawnProcess(args, std.stdio.stdin, std.stdio.stdout, 
std.stdio.stderr, null, std.process.Config.none, workDir);
}

I compile with dmd and then start the application. I always 
receive an error "Failed to spawn new process". As I specify the 
work directory, this should work, or?

Kind regards
André
Oct 04 2016
next sibling parent reply Adam D. Ruppe <destructionator gmail.com> writes:
Are you sure npm is in the path? From your shell, do `which npm` 
and see where it is coming from, you might want to use the full 
path to spawn process.
Oct 04 2016
parent Andre Pany <andre s-e-a-p.de> writes:
On Tuesday, 4 October 2016 at 13:18:45 UTC, Adam D. Ruppe wrote:

 Are you sure npm is in the path? From your shell, do `which 
 npm` and see where it is coming from, you might want to use the 
 full path to spawn process.


Yes, npm is in path. From all directories I can execute npm/node 
(--version)
and receive a valid result.
I can execute npm start within folder "js" in both consoles, git 
bash and windows cmd.
There it works fine.

On windows cmd which is not a known command. On git bash I 
receive as result:
/c/Program Files/nodejs/npm

Kind regards
André
Oct 04 2016
prev sibling parent reply FreeSlave <freeslave93 gmail.com> writes:
On Tuesday, 4 October 2016 at 12:58:19 UTC, Andre Pany wrote:

 Hi,

 I need to call a Node application. node and npm are in windows 
 path variable.
 I have following folder structure:
 ./app.d
 ./js/helloworld.js
 ./js/package.json

 [...]


npm is .cmd file on Windows. Maybe this is issue. Looks like 
cmd.exe knows how to deal with them, while CreateProcess does not.
Oct 04 2016
parent reply Andre Pany <andre s-e-a-p.de> writes:
On Tuesday, 4 October 2016 at 13:52:23 UTC, FreeSlave wrote:

 On Tuesday, 4 October 2016 at 12:58:19 UTC, Andre Pany wrote:

 Hi,

 I need to call a Node application. node and npm are in windows 
 path variable.
 I have following folder structure:
 ./app.d
 ./js/helloworld.js
 ./js/package.json

 [...]


 npm is .cmd file on Windows. Maybe this is issue. Looks like 
 cmd.exe knows how to deal with them, while CreateProcess does 
 not.


I just tried the D coding on Ubuntu Sub System for windows.
Spawn process is working fine on linux, only on windows it 
doesn't work.
I will create a bug report.

Kind regards
André
Oct 04 2016
parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Tuesday, 4 October 2016 at 16:55:22 UTC, Andre Pany wrote:

 Spawn process is working fine on linux, only on windows it 
 doesn't work.
 I will create a bug report.


This isn't really a bug if it is a cmd file like the other poster 
said... cmd files are scripts that need to be run through the 
interpreter.

shellExec probably handles it, or you could spawnProcess "cmd" 
with the npm being an argument to it.
Oct 04 2016
parent reply FreeSlave <freeslave93 gmail.com> writes:
On Tuesday, 4 October 2016 at 17:02:34 UTC, Adam D. Ruppe wrote:

 On Tuesday, 4 October 2016 at 16:55:22 UTC, Andre Pany wrote:

 Spawn process is working fine on linux, only on windows it 
 doesn't work.
 I will create a bug report.


 This isn't really a bug if it is a cmd file like the other 
 poster said... cmd files are scripts that need to be run 
 through the interpreter.

 shellExec probably handles it, or you could spawnProcess "cmd" 
 with the npm being an argument to it.


There's no shellExec, but executeShell.
spawnShell would fit better since author used spawnProcess in 
original post.

Whether spawnProcess should handle .bat and .cmd is a matter of 
function design really. Actually I would like to treat 
spawnProcess more like double-click on application and 
double-click works for scripts on windows. So there will be no 
special code for phobos user to handle this case.
Oct 04 2016
parent Andre Pany <andre s-e-a-p.de> writes:
On Tuesday, 4 October 2016 at 18:41:16 UTC, FreeSlave wrote:

 On Tuesday, 4 October 2016 at 17:02:34 UTC, Adam D. Ruppe wrote:

 On Tuesday, 4 October 2016 at 16:55:22 UTC, Andre Pany wrote:

 Spawn process is working fine on linux, only on windows it 
 doesn't work.
 I will create a bug report.


 This isn't really a bug if it is a cmd file like the other 
 poster said... cmd files are scripts that need to be run 
 through the interpreter.

 shellExec probably handles it, or you could spawnProcess "cmd" 
 with the npm being an argument to it.


 There's no shellExec, but executeShell.
 spawnShell would fit better since author used spawnProcess in 
 original post.

 Whether spawnProcess should handle .bat and .cmd is a matter of 
 function design really. Actually I would like to treat 
 spawnProcess more like double-click on application and 
 double-click works for scripts on windows. So there will be no 
 special code for phobos user to handle this case.


I found the trick. If I change args to ["npm.cmd", "start"] it 
will work.
I do not know whether spawnProcess should handle npm vs npm.cmd 
automatically.
Should I close the bug report?

In the beginning I used executeShell, but had some issue to stop 
the started
server applications. Somehow the server applications weren't
stopped although kill and wait were executed. The same scenario 
is working fine
with spawnProcess.

Kind regards
André
Oct 04 2016