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Hack 65. Put Screenshots Automatically on the Web

Show off to the world what you're up to.

This little hack is fun. It does not improve system performance in any way, but it allows you to share with the world what you're currently doing. This hack is a perfect way for you to demonstrate how cool your Linux desktop is by automatically taking screenshots of your desktop and uploading them to a web server.

The script this hack uses to upload the screenshot is written in Perl and requires Net::FTP, a web server, and a simple program called scrot; all of these are freely available online.

8.12.1. Installing scrot

You can find scrot, a command-line screen-capture tool (similar to import, which is included with ImageMagick), at Extract, compile, and install the software with these few commands:

foo@bar:~$ wget
foo@bar:~$ tar -zxvf scrot-0.8.tar.gz
foo@bar:~$ cd scrot-0.8
foo@bar:~$ ./configure
foo@bar:~$ make
foo@bar:~$ su -c "make install"

With scrot installed, you can use it to take screenshots anytime you want; just find the nearest terminal and type scrot. For more information on scrot, see the manpage.

Perl is likely to be installed already on your Linux system, but if it isn't, you should use your distribution's installation tool to install it. In addition to the stock Perl installation, you also need the Net::FTP module that you can install by using CPAN, Perl's module repository:

foo@bar:~# perl -e shell -MCPAN
foo@bar:~# install Net::FTP

8.12.2. The Code

This is where all the magic is. Just write each line into your favorite text editor, whether it is emacs or vim or something else, and save it as in $localfolder:

#!/usr/bin/perl -w 
use Net::FTP; # Start FTP 

## Define your variables 
$delay = "60"; # Set the screen captures in seconds 
$quality = "50"; # Set the quality of the screenshot
$thumb = "25"; # Set percentage of the thumbnail produced 
$server = ""; # Hostname of the server 
$username = "username"; # Put your username for the server here 
$password = "password"; # Put your password for the server here 
$serverfolder = "/home/me/www"; # This is the folder that you want the pictures to 
end up in 
$localfolder = "/home/me/autoscreensnap"; # This is the folder in which you are 
going to locally save the screenshots 

while( ) 
  system("scrot $localfolder/currentscreen.jpg --thumb $thumb --quality $quality"); 
# Let's take the screenshot
  $ftp = Net::FTP->new($server, Debug => 0); # Connect to FTP server 
  $ftp->login($username, $password); # Let's log in 
  print "OK Connected \n"; 
  $ftp->cwd($serverfolder); # Change to the directory you want uploaded image to 
 be in 
  print "OK Changed directories \n"; 
  $ftp->binary( ); # Set binary mode so the picture works 
  $ftp->delete("$serverfolder/currentscreen.jpg"); # Delete old screenshot
  $ftp->delete("$serverfolder/currentscreen-thumb.jpg"); # Delete old thumbnail 
  print "Deleted old screenshots\n"; 
  $ftp->put("$localfolder/currentscreen.jpg"); # Uploading... 
  $ftp->put("$localfolder/currentscreen-thumb.jpg"); #Upload some more.. 
  print "OK Finished uploading files\n"; 
  $ftp->quit; # Close session 
  print "Sleeping for $delay seconds\n\n"; 
  system("sleep $delay"); 

The first half of the script is just to define all your variables. It is safe to change these and it is recommended that you do change them to suit your needs. These options include the following:


Determines how long the script will wait, in seconds, until it repeats the loop.


Controls the quality of the screenshot that will be taken. I suggest you use a low number so that it doesn't take long to upload or download the screenshot.


Defines what percentage of your resolution the thumbnail should be.


The host of your web server; hopefully it has FTP running on it.


The folder on your web server that will be accessible by the World Wide Web.


Represents the folder where you are going to store the screenshots. I recommend you put it in your home folder just to make everything easy.

The second half of the script uses a loop that repeats itself over and over again. The first command tells the script to use scrot to take a screenshot and create a thumbnail. Then it connects to the web server and changes to a directory visible on the Internet. Once the script has completed, it deletes any old screenshots and thumbnails and uploads the new ones. After it completes this job, it sleeps for 60 seconds by default (this is adjustable) and then continues the loop once again.

8.12.3. Running the Code

To run the script first change the directory to $localfolder. Your script should be sitting in this folder. Now you can run it in two different ways. You can run the script independently with the following commands:

foo@bar:~$ chmod 777
foo@bar:~$ ./

An alternative is to run it with the Perl interpreter:

foo@bar:~$ perl

John Cheng

    Team LiB
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