src/ChildProcess.purs

   1 module PursLoader.ChildProcess
   2   ( ChildProcess()
   3   , spawn
   4   ) where
   5
   6 import Control.Monad.Aff (Aff(), makeAff)
   7 import Control.Monad.Eff (Eff())
   8 import Control.Monad.Eff.Exception (Error())
   9
  10 import Data.Function
  11
  12 foreign import data ChildProcess :: !
  13
  14 spawn :: forall eff. String -> [String] -> Aff (cp :: ChildProcess | eff) String
  15 spawn command args = makeAff $ runFn4 spawnFn command args
  16
  17 foreign import spawnFn """
  18 function spawnFn(command, args, errback, callback) {
  19   return function(){
  20     var child_process = require('child_process');
  21
  22     var process = child_process.spawn(command, args);
  23
  24     var stdout = new Buffer(0);
  25
  26     var stderr = new Buffer(0);
  27
  28     process.stdout.on('data', function(data){
  29       stdout = Buffer.concat([stdout, new Buffer(data)]);
  30     });
  31
  32     process.stderr.on('data', function(data){
  33       stderr = Buffer.concat([stderr, new Buffer(data)]);
  34     });
  35
  36     process.on('close', function(code){
  37       var output = stdout.toString();
  38
  39       var error = output.length === 0 ? stderr.toString() : output + "\n" + stderr.toString();
  40
  41       if (code !== 0) errback(new Error(error))();
  42       else callback(output)();
  43     });
  44   };
  45 }
  46 """ :: forall eff. Fn4 String
  47                        [String]
  48                        (Error -> Eff (cp :: ChildProcess | eff) Unit)
  49                        (String -> Eff (cp :: ChildProcess | eff) Unit)
  50                        (Eff (cp :: ChildProcess | eff) Unit)