Difference between UNIX and Linux

UNIX and Linux are two different Operating Platform. And thus, In this article, we brought you the common Difference between UNIX and Linux. We hope you will learn a lot more.

Difference between UNIX and Linux

What is UNIX? Definition and description of the UNIX Operating System

UNIX OS is not an open-source OS, and nowadays, it is a pure Unix OS.
This UNIX is an operating system that was first developed in the 1960s and has been under constant development ever since. Unix is a portable, multitasking, multiuser, time-sharing OS. In this case, PCs widely use UNIX OS, servers, and mobile devices. Hence, The Unix environment was also an essential element in the development of the Internet and networking.

Unix systems are:

The use of text files for data storage:

  • A hierarchical file system.
  • A large number of small programs string together through a command-line interpreter.
  • Use of shell scripts.
  • The avoidance of captive user interfaces is that Unix had a significant impact on other operating systems and can be credited (in whole or part) for the following:
  • The use of high-level language in operating systems
  • Hierarchical file systems
  • Its syntax for regular expressions found widespread use
  • Unix shell inspired many of the command line interpreters that followed
  • C programming language became more ubiquitous
  • Began the movement toward modularity and reusability in software engineering
  • Helped contribute to the explosion of the Internet by making TCP/IP protocol more widely available.
  • Contributed to the launch of the free software movement

UNIX is a trademark. AT&T owned it, then it got sold and sold and sold and now needs a web search to find out its owner and track its ownership history.OpenGroup certifies an operating system to be “UNIX” or lack of it. So, Solaris, HP UX, IBM AIX, Mac OS X (yes!) are all certified UNIXes. These are not free and indeed not open source. Solaris has an open-source version for x86 architecture.

The UNIX operating system is made up of three parts:

  • kernel.
  • shell.
  • Programs.

The kernel :
The kernel of UNIX is the hub of the operating system: it allocates time and memory to programs and handles the filestore and communications in response to system calls.

The shell :
The shell acts as an interface between the user and the kernel. When a user logs in, the login program checks the username and password and then starts another program called the shell. The shell is a command-line interpreter (CLI). It interprets the commands the user types in and arranges for them to be carried out. The commands are themselves programs: when they terminate, the shell gives the user another prompt (% on our systems).

The programs :
UNIX programs are the software of the UNIX OS, which can use Operating service, Utility, and other Application service software.

Linux OS defines and description.

Linux is UNIX Clone :

But if you consider Portable Operating System Interface (POSIX) standards, then Linux can be considered as UNIX. To quote from Official Linux kernel README file,
Linux is a Unix clone written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the Net. It aims towards POSIX compliance.
However, “Open Group” disapproves of the construction “Unix-like” and consider it a misuse of their UNIX trademark.

Linux Is Just a Kernel :

Linux is just a kernel. All Linux distributions includes GUI system + GNU utilities (such as cp, mv, ls,date, bash etc) + installation & management tools + GNU c/c++ Compilers + Editors (vi) + and various applications (such as OpenOffice, Firefox). However, most UNIX operating systems are considered as a complete OS as everything come from a single source or vendor.
As I said earlier, Linux is just a kernel, and Linux distribution makes it complete usable operating systems by adding various applications. Most UNIX operating systems come with A-Z programs such as editor, compilers, etc. For example, HP-UX or Solaris comes with A-Z programs.

License and cost :

Linux is Free (as in beer [freedom]). You can download it from the Internet or redistribute it under GNU licenses. You will see the best community support for Linux. Most UNIX like OS is not free (but this is changing fast, for example, OpenSolaris UNIX). However, some Linux distributions such as Redhat / Novell provides additional Linux support, consultancy, bug fixing, and training for additional fees.

User-Friendly :

Linux is considered as most user-friendly UNIX like OS. It makes it easy to install a sound card, flash players, and other desktop goodies. However, Apple OS X is the most popular UNIX OS for desktop usage.

Security Firewall Software :

Linux comes with an open-source Netfilter/iptables based firewall tool to protect your server and desktop from the crackers and hackers. UNIX operating systems come with its firewall product (for example, Solaris UNIX comes with filter-based firewall), or you need to purchase a 3rd party software such as Checkpoint UNIX firewall.

Backup and Recovery Software :

UNIX and Linux come with a different set of tools for backing up data to tape and other backup media. However, both of them share some standard tools such as tar, dump/restore, and cpio, etc.

File Systems :

  • Linux by default supports and use ext3 or ext4 file systems.
  • UNIX comes with various file systems such as jfs, gpfs (AIX), jfs, gpfs (HP-UX), jfs, gpfs (Solaris).

System Administration Tools :

  • UNIX comes with its tools, such as SAM on HP-UX.
  • Suse Linux comes with Yast
  • Redhat Linux comes with its GUI tools called RedHat-config-*. However, editing text config files and typing commands are the most popular options for sysadmin work under UNIX and Linux.

System Startup Scripts :
Almost every version of UNIX and Linux comes with system initialization script but they are located in different directories:

HP-UX – /sbin/init.d
AIX – /etc/rc.d/init.d
Linux – /etc/init.d

End-User Perspective :
The differences are not that big for the average end-user. They will use the same shell (e.g. bash or ksh) and other development tools such as Perl or Eclipse development tool.

System Administrator Perspective :
Again, the differences are not that big for the system administrator. However, you may notice differences while performing the following operations.

Software installation procedure :

Hardware device names
Various admin commands or utilities
Software RAID devices and mirroring
Logical volume management

UNIX OS Names :

A few popular names :

Sun Solairs
Mac OS X

Linux Distribution (OS) Names

A few popular names :

Redhat Enterprise Linux
Fedora Linux
Debian Linux
Suse Enterprise Linux
Ubuntu Linux

Common Things Between Linux & UNIX :

Both share many common applications such as:
GUI, file, and windows managers (KDE, Gnome)
Shells (ksh, csh, bash)
Various office applications such as OpenOffice.org
Development tools (perl, php, python, GNU c/c++ compilers)
Posix interface

Leave a Reply