Synaptic Removed From Ubuntu Linux v11.10

Posted on in Categories Ubuntu Linux last updated June 25, 2011

Synaptic is a front-end for the apt package management system. The program allows you to perform all actions of the command line tool apt-get in a graphical environment such as installing, upgrading, downgrading and removing of single packages or even upgrading your whole system. The upcoming Ubuntu Linux version 11.10 (code named Oneiric Ocelot) has removed Synaptic Package Manager.

Download of the day: atool for Managing File Archives of Various Types

Posted on in Categories Download of the day, File system, Linux, UNIX last updated February 6, 2008

atool is a script for managing file archives of various types such as .zip, tar.gz and all other formats. From the article:

Atool uses other tools behind the scenes to perform the heavy lifting. With atool, you can handle any archive without having to remember what command-line tool to use to expand it and which options that particular tool expects. Atool comes with a collection of commands, including aunpack, apack, als, acat, adiff, and arepack. The tools are all links to the main atool Perl script, but they perform the actions that their name suggests — for example, unpacking or creating a new archive.

Debian / Ubuntu Linux user can install atool using apt-get command, enter:
$ sudo apt-get install atool
$ aunpack backuo.tar.gz
$ aunpack -e *.tar.gz
$ apack foo bar
$ man atool

Download atool

=> Download atool package (via

Linux: Monitor Hard Disks Temperature With hddtemp

Posted on in Categories CentOS, Debian Linux, Hardware, Howto, Linux, Monitoring, RedHat/Fedora Linux, Suse Linux, Tips, Troubleshooting, Tuning, Ubuntu Linux last updated July 7, 2010

There is a nice utility to monitor hard drive temperature. Most modern x86 computer hard disk comes with S.M.A.R.T (Self-Monitoring, Analysis, and Reporting Technology). It is a monitoring system for computer hard disks to detect and report on various indicators of reliability, in the hope of anticipating failures.

Linux or UNIX password protect files

Posted on in Categories Debian Linux, FreeBSD, Howto, Linux, OpenBSD, RedHat/Fedora Linux, Security, Solaris, Suse Linux, Tips, Ubuntu Linux, UNIX last updated December 14, 2007

From my mailbag:

Q. How do I password protect files?

Linux and other Unixish oses offers strong file permissions and ACL (access control list) concept in Linux/UNIX computer security used to enforce privilege separation.

However, none of them offers a password to protect files. You can use GNU gpg (GNU Privacy Guard) encryption and signing tool. It is a suite of cryptographic software. Many new UNIX/Linux users get confused with this fact.

Solution is to use following commands to encrypt or decrypt files with a password.

mcrypt command

Mcrypt is a simple crypting program, a replacement for the old unix crypt. When encrypting or decrypting a file, a new file is created with the extension .nc and mode 0600. The new file keeps the modification date of the original. The original file may be deleted by specifying the -u parameter.


Encrypt data.txt file:
$ mcrypt data.txt

Enter the passphrase (maximum of 512 characters)
Please use a combination of upper and lower case letters and numbers.
Enter passphrase:
Enter passphrase:

A new file is created with the extension .nc i.e.

$ ls
$ cat

Decrypt the file:
$ mcrypt -d

Enter passphrase:
File was decrypted.

Verify that file was decrypted:

$ ls data.txt
$ cat data.txt

For mcrypt to be compatible with the Solaris des, the following parameters are needed:
$ mcrypt -a des --keymode pkdes --bare -noiv data.txt
Delete the input file if the whole process of encryption/decryption succeeds (pass -u option):
$ mcrypt -u data.txt
$ mcrypt -u -d

openssl command

OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and related cryptography standards required by them. You can use the openssl program which is a command line tool for using the various cryptography functions of OpenSSL’s crypto library from the shell. It can be used for encrypt and decrypt files with a password:


Encrypt file.txt to file.out using 256-bit AES in CBC mode
$ openssl enc -aes-256-cbc -salt -in file.txt -out file.out
Decrypt encrypted file file.out
$ openssl enc -d -aes-256-cbc -in file.out

  • enc : Encoding with Ciphers.

See also: