asynchronous - Meteor callback to sys.exec inside a Meteor.call callback -

i have event triggering metor.call():

meteor.call("runcode", mycode, function(err, response) {   session.set('code', response);   console.log(response); }); 

but runcode function inside server's metheor.methods has inside callback , can't find way make return response in above code.

runcode: function(mycode) {   var command = 'pwd';    child = exec(command, function(error, stdout, stderr) {     console.log(stdout.tostring());     console.log(stderr.tostring());      // want return stdout.tostring()     // returning here causes undefined because runcode doesn't return   });    // can't return here because don't have yet valuer of stdout.tostring(); } 

i'd way have exec callback return runcode without setinterval work, hacky way in opinion.

you should use future fibers.

see docs here : https://npmjs.org/package/fibers

essentially, want wait until asynchronous code run, return result of in procedural fashion, future does.

you find out more here : https://www.eventedmind.com/feed/ww3rqrhjo8flgk7ff

finally, might want use async utilities provided package : https://github.com/arunoda/meteor-npm, make easier.

// load future fibers var future=npm.require("fibers/future"); // load exec var exec=npm.require("child_process").exec;  meteor.methods({     runcode:function(mycode){         // method call won't return immediately, wait         // asynchronous code finish, call unblock allow client         // queue other method calls (see meteor docs)         this.unblock();         var future=new future();         var command=mycode;         exec(command,function(error,stdout,stderr){             if(error){                 console.log(error);                 throw new meteor.error(500,command+" failed");             }             future.return(stdout.tostring());         });         return future.wait();     } });