Monthly Archives: April 2014

Useful Linux Commands

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Locate PHP error logs on the server

grep 'error_log' /etc/php.ini | awk -F= '{ print $2; }'

Restart your bash_profile

. ~/.bash_profile

Change to your home directory

cd ~

View your history

history 50

Search your history

Ctrl+R then type what you're looking for

Search files in a directory

grep -Rn what_your_looking_for path_to_directory_you_want_to_search

Change file permissions

chmod filename_here permissions_here

Change permissions for all files in a directory

chmod -R path_to_directory permissions_here

Edit crontabs

crontab -e

Restart apache service

service httpd restart

Restart apache

/etc/init.d/httpd restart

Figure out which directory you’re in

pwd

List all files and hidden files in a directory

ls -la

Auto-complete path file names

start typing the file name in the directory then hit the tab key. Hit it twice to show all files matching what you've typed so far

Display a part of a file without opening an editor

cat path_to_file

Extract all files from a .tar.gz archive

tar -zxvf path_to_archive.tar.gz

Move a file or folder directory

mv path_to_file new_path_to_file

Remove a file

rm path_to_file

Remove a folder directory

rm -Rf path_to_folder

Create a folder directory

mkdir path_to_folder_you_want_to_make

Copy a file

cp path_to_file path_to_file_copy

Copy a folder directory

cp path_to_folder path_to_folder_copy

View help files for a command

man command

Google Maps Tutorial: You Are Here in 3 Easy Steps

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I’ve been playing with Google maps lately and I thought I would share this little tidbit. It still needs some refinement (ie fetching your location from IP for non-html5 compliant browsers and letting you set your location) but it may give you the start you were looking for.

1. Create a Google maps API key

You can find the instructions on the Google maps Getting Started documentation. Basically you need to generate the key for the website that will be hosting this code so that Google will honor the API request.

2. Create a PHP File

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>You Are Here</title>
    <style>
      html, body {
        height: 100%;
        margin: 0px;
        padding: 0px
      }
            
      #map-canvas {
        float: right;
        height: 100%;
        margin: 0px;
        padding: 0px
      }
    </style>
    <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
        <script src="javascript.js"></script>
  </head>
  <body>
    <div id="map-canvas" />
  </body>
</html>

3. Create a Javascript File

I called mine javascript.js. If you change the name you’ll need to update it in your .php file above.

/**
* Purpose: ask the browser for the user's location (html5)
* Preconditions: html5 is enabled on the browser
* Postconditions: map initialized with user's position if browser is html5 enabled and position given
**/
function getLocation()
{
    if (navigator.geolocation)
        navigator.geolocation.getCurrentPosition(initMap);
    else
        alert("Geolocation is not supported by this browser.");
}

/**
* Purpose: start the google map
* Preconditions: position object
* Postconditions: map centered around the user's position with a zoom of 15
**/
function initMap(position) {

    console.log('Your position is:', position.coords.latitude, position.coords.longitude);
    
  var mapOptions = {
    zoom: 15,
    center: new google.maps.LatLng(position.coords.latitude, position.coords.longitude)
  };

  var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
    var position = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
 
    setMarker(map, position, "You!", "You Are Here");
}

/**
* Purpose: set a marker on a map
* Preconditions: map reference, position, title of the marker window, message in the marker window
* Postconditions: marker event listener added to the map
**/
function setMarker(map, position, title, message) {

     var marker = new google.maps.Marker({
      position: position,
      map: map
    });
        
  marker.setTitle(title);
        
  var infowindow = new google.maps.InfoWindow({
    content: message
  });

  google.maps.event.addListener(marker, 'click', function() {
    infowindow.open(marker.get('map'), marker);
  });
}

google.maps.event.addDomListener(window, 'load', getLocation);

Demo Working Code

Want to see what it does? Fork this plunker to try it out and see the code. Remember you have to be using a HTML5 compliant browser and give it permission to view your location.