Generate QR Code in Ubuntu Linux

You can easily generate QR Code under Ubuntu using the command line ‘qrencode’ package. In Ubuntu 11.04 Natty Narwhal, you can install qrencode using this command:

apt-get install qrencode

To generate QR Code image, you only need to run this command:
qrencode -l L -v 1 -o qrcode-test.png "Hello, World!"

QR Code is a form of 2 dimensional barcode which can store arbitary text data including URL, email or plain text. For more information, please refer to the QR Code Wikipedia Entry

Easy File Encryption On Ubuntu Linux with OpenSSL

Here’s an easy way to encrypt your file using OpenSSL. The general syntax is:

openssl enc (cipher) -e -in (input file) -out (output file)

so to encrypt a “plaintext.txt” file, using aes256, you only need to run this command:

openssl enc aes256 -e -in plaintext.txt -out encrypted.txt

Similarly, to decrypt the file, you can run the command:

openssl enc aes256 -d -in encrypted.txt -out decrypted.txt