I need blender command-line access though spawn but keep running into an ENOENT error and it is hard to pinpoint what is missing. The command-line being passed in the sample application works in terminal.
Below are some details about the environment and the sample script I am using.
Environment (OSX El Capitan)
Installed Blender 2.76b with:
brew install Caskroom/cask/blender
Then add alias to bash_profile for terminal access:
alias blender="/Applications/blender/Blender.app/Contents/MacOS/blender"
Test Code
#!/usr/bin/env node
var child_process = require('child_process');
var arguments = [
'-b',
'recipe.blend',
'-o', 'test-#',
'-f', 0
];
console.log("values: ", arguments);
var child = child_process.spawn('blender', arguments);
child.stdout.on('data', function(data) {
console.log('data out: ', data.toString());
});
child.stderr.on('data', function(data) {
console.error('error out: ',data);
});
child.on('close', function(code) {
console.log('closing code: ' + code);
});
// Raw command-line for terminal. (PASS)
// blender -b recipe.blend -o test-# -f 0
Try changing the child_process.spawn('blender', arguments); line to child_process.spawn('/Applications/blender/Blender.app/Contents/MacOS/blender', arguments);. NodeJS won't be using your bash aliases, so unless the blender executable is in its PATH it won't be able to find the executable and will throw an ENOENT.
The other option is adjusting Node's PATH to include the path to the blender executable. You could also pass the fullpath to the blender executable in as an environment variable.
Cheers!
Related
When creating a CLI I would like to test my function. For that I'm using the module child_process.
const path = require('path');
const { execFile } = require('child_process');
describe('cli test', () => {
test('thing', () => {
const myCli = execFile(
`${path.resolve(__dirname, '..')}/cli.js`, ['--foo', 'Bar'],
(err, stdout, stderr) => {
if (err) {
console.log('err: ', err);
}
});
});
But this produces the following error:
Attempted to log "err: { Error: spawn /projects/cli/src/cli.js EACCES
at Process.ChildProcess._handle.onexit (internal/child_process.js:240:19)
at onErrorNT (internal/child_process.js:415:16)
at process._tickCallback (internal/process/next_tick.js:63:19)
errno: 'EACCES',
code: 'EACCES',
Running this script directly in the terminal via the command: $ node cli.js --foo Bar works perfectly.
Now a suggestion is to chmod +x <file> that file (source). But the test should also work on CI, and on a different computer which pulls the Git repo.
Any idea?
I'd suggest using fork instead of execFile.
The child_process.fork() method is a special case of child_process.spawn() used specifically to spawn new Node.js processes.
This will allow you to execute JS files without needing them to be shell executable.
To the best of my knowledge, git actually tracks the executable bit for files. There are some things to consider though as pointed out in this article: https://medium.com/#tahteche/how-git-treats-changes-in-file-permissions-f71874ca239d
Another solution would be to not rely on the ./ execution syntax (which requires the executable bit to be turned on for the respective file) but instead to explicitly use the shell command:
const path = require('path');
const { execFile } = require('child_process');
describe('cli test', () => {
test('thing', () => {
const myCli = execFile(
`sh ${path.resolve(__dirname, '..')}/cli.js`, ['--foo', 'Bar'],
(err, stdout, stderr) => {
if (err) {
console.log('err: ', err);
}
});
});
Notice the sh prefix I added to your code, This way you thell the sh command (which should be available in all of your environments e.g. the CI) to execute the contents of the file, regardless of whether the file itself can be executed or not!
I was receiving an EACCESS -13 error from child_process.spawn when trying to run a the command line mysql command.
There was something wrong with my PATH and updating it to add /usr/local/mysql/bin/ resolved the problem.
The temporary fix is to run export PATH=$PATH:/usr/local/mysql/bin/.
The permanent fix is to:
type: sudo nano /etc/paths
Add /usr/local/mysql/bin at the end
Ctrl + X
Yes
Enter key
type hash -r # command line or close the terminal app and open it again
NOTE: I got the temporary fix from a site ... I don't know why it has a / on the end of the bin but all of the mysql executables appear to be available without it in the /etc/paths file
I am trying to execute a nodejs file called create-MySwitch.js through a child process in my main.js file.
this is the code for main.js
const exec = require('child_process').exec;
var cmdStr = 'node /home/pi/Desktop/lan-device/create-MySwitch.js';
exec(cmdStr,
{argv: {
port:8080,
uuid:'MyThing'
}},
(error, stdout, stderr)=>{
if (error) {
console.error('exec error: ${error}');
console.log(error);
return;
}
console.log('stdout: ${stdout}');
console.log('stderr: ${stderr}');
});
This is how I am attempting to access the arguments in the create-MySwitch.js file
var port_value = process.argv.port;
var uuid_value = process.argv.uuid;
The output is
stdout: ${stdout}
stderr: ${stderr}
when I run the command
node main.js
I do not think it's working because the output from executing the create-MySwitch.js file should be 'ready', but clearly is not being printed in the stdout variable from the child process.
Essentially, what I am trying to do is run the command 'node createMySwitch.js ', but instead of just typing this in to the command prompt I want to run that command using a child process.
I am doing all of this using the raspbian operating system.
I'm on node v4.4.0 and on Windows 10. I'm using bunyan to log my node application.
try {
var fs = require('fs');
var path = require('path');
var spawn = require('child_process').spawn;
var through = require('through');
} catch (err) {
throw err;
}
var prettyStream = function () {
// get the binary directory of bunyan
var bin = path.resolve(path.dirname(require.resolve('bunyan')), '..', 'bin', 'bunyan');
console.log(bin); // this outputs C:\www\nodeapp\src\node_modules\bunyan\bin\bunyan, the file does exist
var stream = through(function write(data) {
this.queue(data);
}, function end() {
this.queue(null);
});
// check if bin var is not empty and that the directory exists
if (bin && fs.existsSync(bin)) {
var formatter = spawn(bin, ['-o', 'short'], {
stdio: [null, process.stdout, process.stderr]
});
// stream.pipe(formatter.stdin); // <- did this to debug
}
stream.pipe(process.stdout); // <- did this to debug
return stream;
}
The logging spits out in the console due to the fact I used stream.pipe(process.stdout);, i did this to debug the rest of the function.
I however receive the error:
Error: spawn C:\www\nodeapp\src\node_modules\bunyan\bin\bunyan ENOENT
at exports._errnoException (util.js:870:11)
at Process.ChildProcess._handle.onexit (internal/child_process.js:178:32)
at onErrorNT (internal/child_process.js:344:16)
at nextTickCallbackWith2Args (node.js:442:9)
at process._tickCallback (node.js:356:17)
at Function.Module.runMain (module.js:443:11)
at startup (node.js:139:18)
at node.js:968:3
I'm guessing this is a Windows error. Anyone have any ideas?
Use {shell: true} in the options of spawn
I was hit with this problem recently so decided to add my findings here. I finally found the simplest solution in the Node.js documentation. It explains that:
child_process.exec() runs with shell
child_process.execFile() runs without shell
child_process.spawn() runs without shell (by default)
This is actually why the exec and spawn behave differently. So to get all the shell commands and any executable files available in spawn, like in your regular shell, it's enough to run:
const { spawn } = require('child_process')
const myChildProc = spawn('my-command', ['my', 'args'], {shell: true})
or to have a universal statement for different operating systems you can use
const myChildProc = spawn('my-command', ['my', 'args'], {shell: process.platform == 'win32'})
Side notes:
It migh make sense to use such a universal statement even if one primairly uses a non-Windows system in order to achieve full interoperability
For full consistence of the Node.js child_process commands it would be helpful to have spawn (with shell) and spawnFile (without shell) to reflect exec and execFile and avoid this kind of confusions.
I got it. On Windows bunyan isn't recognized in the console as a program but as a command. So to invoke it the use of cmd was needed. I also had to install bunyan globally so that the console could access it.
if (!/^win/.test(process.platform)) { // linux
var sp = spawn('bunyan', ['-o', 'short'], {
stdio: [null, process.stdout, process.stderr]
});
} else { // windows
var sp = spawn('cmd', ['/s', '/c', 'bunyan', '-o', 'short'], {
stdio: [null, process.stdout, process.stderr]
});
}
I solved same problem using cross-spawn. It allows me to spawn command on both windows and mac os as one common command.
I think you'll find that it simply can't find 'bunyun', but if you appended '.exe' it would work. Without using the shell, it is looking for an exact filename match to run the file itself.
When you use the shell option, it goes through matching executable extensions and finds a match that way. So, you can save some overhead by just appended the executable extension of your binary.
I was having this same problem when trying to execute a program in the current working directory in Windows. I solved it by passing the options { shell: true, cwd: __dirname } in the spawn() call. Then everything worked, with every argument passed as an array (not attached to the program name being run).
I think, the path of bin or something could be wrong. ENOENT = [E]rror [NO] [ENT]ry
I'm trying to do a little application with node.js that would run on mac and execute some commands.
I've successfully used spawn to run command lines such as xcodebuild, but xcrun doesn't seems to work when I try to open the iOS Simulator.
I can open on terminal by typing:
xcrun instruments -w 'iPhone 5s (9.2)' -t <template>
But if I use node and try to use spawn like this:
var args = ['instruments', '-w', `iPhone 5s (9.2)`, '-t', 'noTemp'];
var xcrun = spawn('xcrun', args);
So it got me thinking that maybe it had some limitation opening apps? I tried to run:
var args = ['/Applications/Spotify.app'];
var xcrun = spawn('open', args);
And nothing happens. I couldn't find anything related to that. My question is: is there anyway to open apps using node.js spawn? If there is, does someone know what's the problem with my code?
Here's the full code if needed:
var args = ['instruments', '-w', `${fullDevice}`, '-t', 'noTemp'];
var xcrun = spawn('xcrun', args);
xcrun.stdout.on('data', (data)=>{
console.log(data.toString('utf8'));
})
xcrun.on('close', (code) => {
socket.emit({
time: commands.getCurrentTime(),
type: 'success',
log: 'Device booted...'
});
callback();
if (code !== 0) {
console.log(`open process exited with code ${code}`);
}
});
OBS: if I run this piece of code the application doesn't terminate, the program doesn't continue and nothing happens.
EDIT: Changed:
xcrun.on('data', (data)=>{
To:
xcrun.stdout.on('data', (data)=>{
Spawned processes have two separate streams for stdout and stderr, so you will need to listen for data on those objects and not the spawned process object itself:
xcrun.stdout.on('data', function(data) {
console.log('stdout: ' + data.toString());
});
xcrun.stderr.on('data', function(data) {
console.log('stderr: ' + data.toString());
});
The problem was one line above. Not sure why, but there's a socket.emit call that is wrong and actually hold the program's execution.
How can I run a command line and get the outputs as soon as available to show them somewhere.
For example if a run ping command on a linux system, it will never stop, now is it possible to get the responses while the command is still processing ?
Or let's take apt-get install command, what if i want to show the progress of the installation as it is running ?
Actually i'm using this function to execute command line and get outputs, but the function will not return until the command line ends, so if i run a ping command it will never return!
var sys = require('sys'),
exec = require('child_process').exec;
function getOutput(command,callback){
exec(
command,
(
function(){
return function(err,data,stderr){
callback(data);
}
}
)(callback)
);
}
Try using spawn instead of exec, then you can tap into the stream and listen to the data and end events.
var process = require('child_process');
var cmd = process.spawn(command);
cmd.stdout.on('data', function(output){
console.log(output.toString()):
});
cmd.on('close', function(){
console.log('Finished');
});
//Error handling
cmd.stderr.on('data', function(err){
console.log(err);
});
See the Node.js documentation for spawn here: https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options