nixpkgs/nixos/gui/chrome/content/io.js

function inspect(obj, maxLevels, level)
{
  var str = '', type, msg;

    // Start Input Validations
    // Don't touch, we start iterating at level zero
    if(level == null)  level = 0;

    // At least you want to show the first level
    if(maxLevels == null) maxLevels = 1;
    if(maxLevels < 1)
        return '<font color="red">Error: Levels number must be > 0</font>';

    // We start with a non null object
    if(obj == null)
    return '<font color="red">Error: Object <b>NULL</b></font>';
    // End Input Validations

    // Each Iteration must be indented
    str += '<ul>';

    // Start iterations for all objects in obj
    for(property in obj)
    {
      try
      {
          // Show "property" and "type property"
          type =  typeof(obj[property]);
          str += '<li>(' + type + ') ' + property +
                 ( (obj[property]==null)?(': <b>null</b>'):('')) + '</li>';

          // We keep iterating if this property is an Object, non null
          // and we are inside the required number of levels
          if((type == 'object') && (obj[property] != null) && (level+1 < maxLevels))
          str += inspect(obj[property], maxLevels, level+1);
      }
      catch(err)
      {
        // Is there some properties in obj we can't access? Print it red.
        if(typeof(err) == 'string') msg = err;
        else if(err.message)        msg = err.message;
        else if(err.description)    msg = err.description;
        else                        msg = 'Unknown';

        str += '<li><font color="red">(Error) ' + property + ': ' + msg +'</font></li>';
      }
    }

      // Close indent
      str += '</ul>';

    return str;
}

// Run xulrunner application.ini -jsconsole -console, to see messages.
function log(str)
{
  Components.classes['@mozilla.org/consoleservice;1']
    .getService(Components.interfaces.nsIConsoleService)
    .logStringMessage(str);
}

function makeTempFile(prefix)
{
  var file = Components.classes["@mozilla.org/file/directory_service;1"]
                       .getService(Components.interfaces.nsIProperties)
                       .get("TmpD", Components.interfaces.nsIFile);
  file.append(prefix || "xulrunner");
  file.createUnique(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0664);
  return file;
}

function writeToFile(file, data)
{
  // file is nsIFile, data is a string
  var foStream = Components.classes["@mozilla.org/network/file-output-stream;1"]
                           .createInstance(Components.interfaces.nsIFileOutputStream);

  // use 0x02 | 0x10 to open file for appending.
  foStream.init(file, 0x02 | 0x08 | 0x20, 0664, 0); // write, create, truncate
  foStream.write(data, data.length);
  foStream.close();
}

function readFromFile(file)
{
  // |file| is nsIFile
  var data = "";
  var fstream = Components.classes["@mozilla.org/network/file-input-stream;1"]
                          .createInstance(Components.interfaces.nsIFileInputStream);
  var sstream = Components.classes["@mozilla.org/scriptableinputstream;1"]
                          .createInstance(Components.interfaces.nsIScriptableInputStream);
  fstream.init(file, -1, 0, 0);
  sstream.init(fstream);

  var str = sstream.read(4096);
  while (str.length > 0) {
    data += str;
    str = sstream.read(4096);
  }

  sstream.close();
  fstream.close();

  return data;
}

function runProgram(commandLine)
{
  // create an nsILocalFile for the executable
  var file = Components.classes["@mozilla.org/file/local;1"]
                       .createInstance(Components.interfaces.nsILocalFile);
  file.initWithPath("/bin/sh");

  // create an nsIProcess
  var process = Components.classes["@mozilla.org/process/util;1"]
                          .createInstance(Components.interfaces.nsIProcess);
  process.init(file);

  // Run the process.
  // If first param is true, calling thread will be blocked until
  // called process terminates.
  // Second and third params are used to pass command-line arguments
  // to the process.
  var args = ["-c", commandLine];
  process.run(true, args, args.length);
}

// only for testing...
function testIO()
{
  var f = makeTempFile();
  writeToFile(f, "essai\ntest");
  alert(readFromFile(f));
  runProgram("zenity --info");
}