title: What does error code 255 mean in Node.js child_process
body: <p>I am running php command from Node.js child_process.
  In response it is showing error and throwing error with error code 255 because of which my script is breaking.</p>
  
  <p>When i execute the command from terminal it works fine but in child_process it gives error.</p>
  
  <pre><code>async function decrypt(cipher){
  
      try {
          var terminal = require('child_process');
      var util     = require('util');
      var exec     = util.promisify(terminal.exec);
      var command  = "usr/bin/php " + basePath + "/decrypt.php '" + cipher +"'";
  
      return await exec(command);
      }catch(err){
          console.log(err);
          console.error(err.code +' | '+ err.message);
      }
  }
  
  module.exports = {
  decrypt : decrypt
  }
  
  
  
  
   { Error: Command failed: /usr/bin/php /var/www/html/nodejs/decrypt.php 'w5oFS8U4NGrleFHtptkmO+luDMw0z+fYrJ/onlj6fndIS/0QrWzOAsTN450VLZwR+GmDkyylybGJXUnx2VdeJQ=='
  
  
  
      at ChildProcess.exithandler (child_process.js:281:12)
  
      at emitTwo (events.js:126:13)
  
      at ChildProcess.emit (events.js:214:7)
  
      at maybeClose (internal/child_process.js:915:16)
  
      at Process.ChildProcess._handle.onexit (internal/child_process.js:209:5)
  
      killed: false,
  
      code: 255,
  
      signal: null,
  
      cmd: '/usr/bin/php /var/www/html/nodejs/decrypt.php \'w5oFS8U4NGrleFHtptkmO+luDMw0z+fYrJ/onlj6fndIS/0QrWzOAsTN450VLZwR+GmDkyylybGJXUnx2VdeJQ==\'',
  
      stdout: '\t\n\n{"error":false,"decryptedText":"0324"}',
  
      stderr: '' }
  </code></pre>
  
  <p>Desired Output is : '{"error":false,"decryptedText":"0324"}'</p>