History of Unix and Linux, Essay Example

Open source software is defined as “software for which the human-readable source code is available for use, study, reuse, modification, enhancement, and redistribution by the users of that software” (Kennedy, 2010). As these open source software are free of cost, organizations started replacing legacy systems with open source products. This trend has forced hardware and software vendors along with proprietary technology vendors to offer value added services associated with open source products. After discussing all these advantages associated with open source software, one question comes in mind i.e. what is the purpose of spending money on proprietary software, and why do some companies do this? The answer is probably because they do not know that an open source meeting all their needs exists.  For example, an open source enterprise resource planning application for Small medium business can be a cost saving alternative for expensive ERP systems such as SAP and Oracle.

Linux is gaining popularity. Drivers leading to this factor include a comprehensive variety of distributions that are nearly to 200. Linux distributions have also contributed to Windows server platforms but a lot of integration efforts are still required (Brooks, 2007). However, organizations having a Windows based server environment are reliant on using Microsoft products on workstations. Although, Linux is gaining popularity for home users, as it is an open source and distributions are downloadable from the Internet.  As per requirements, we will compare and discuss Fedora and Ubuntu, as they are one of the two distributions from several others.

The two distributions of Linux i.e. Ubuntu and Fedora are comprehensively tracked on Distrowatch (Fedora and ubuntu compariso, n.d). There are lot of comparisons and dissimilarities available about these two distributions, but apart from having more or less features; there is no conclusion of declaring any one of them as a winner. Both of these Linux distributions were founded by Mark Shuttleworth (Fedora and ubuntu compariso, n.d). Likewise, these two distributions have marked their importance due to their demand and rapidly evolving versions bundled with features including ease of use, security, flexibility and compatibility.

It is possible for an operating system to be matured as well as state of the art simultaneously? If it is UNIX, then the answer would be “Yes.” UNIX has contributed in the Information technology sector for the last 25 years. Millions of installations conducted on various platforms and UNIX has proved to be organized and scalable. UNIX invented in 1969, by the computer scientists Dennis Ritchie and Kenneth Thompson employed at AT&T bell labs. Operating systems are compared by their functionality and performance. UNIX has contributed immensely in recent years. UNIX communication capabilities has also contributed in High performance computing sector as a company named Computer Associated International implemented a powerful system “Advantage Gen (release 6.5)”on UNIX platform to speed up the development of J2EE applications and web services(Ohio supercomputing center to deploy hp Linux supercomputer.2002). UNIX back end server support the automatic generation of enterprise java beans facilitated the development teams to develop the J2EE application more efficiently. By the UNIX fast XML proxy support, web services are developed in no time on a distributed system as compared to the previous server architecture.

IBM 32 way UNIX servers were also launched in year 2001 with the code name “Regatta”. The microprocessor architecture comprises of 1 GHz 64 Bit Power 4. This UNIX server is capable of self-healing technology and to decrease system failures. The system is capable to divide into 16 virtual servers which enable the businesses to unite several machines in to one.

The Client-server model of UNIX was the core components for the growth of Internet and reshaping of the distributed systems networks. Inter process communication in the UNIX operating system involves the connection between the system components logically and physically. It supports real time network applications which allow the user to exchange messages in an interactive session. UNIX is known as a command line interface due to nonexistence of a GUI environment Today UNIX is equipped with a GUI along with dynamic communication functionalities. Some of the registered UNIX products are HP-UX, IBM AIX, SCO UnixWare, SGI IRIX, Sun Solaris etc.

UNIX communication mechanism is used to transfer information between two processes. These are called pipes and are also called special files, which only save a limited amount of data. The pipe uses FIFO (First in First Out) mechanism to retrieve data. The data is written at one end of the pipe and can be read on the other end. The system cannot identify the processes at the other end of the pipe. The system also provides synchronization between reading and writing process. The system block the pipes already involved in processing data and constantly monitor the pipes to assure the processes are running at both ends of the pipes. The deadlock prevention is handled by the programmers.

UNIX has limited the pipes to 512 K. Write ( ) un-buffered is used to add data to the pipes. The system assured that no interleaving will occur even if the pipes fill on a temporary basis. For the retrieval of data, read ( ) is used. The pipes ( ) call is used to rename un-named pipes in UNIX. The command retrieves two pipes supporting bi directional communication. Pipe is used for sending the output of one process to another process as input. When a pipe process in initialized, both processes run concurrently and the system cannot assure on which sequence each process is allowed to run. UNIX communication mechanism manages the producer and the consumer issue, both processes proceed and the system provides automatic blocking when required. Sockets can be divided on to two categories:

Streams

Stream sockets guarantees the delivery of data, in the same order as it is sent. In the process of stream socket, a connection is established, and the two ends must agree logically before sending the data.

Datagram

Datagram sockets do not guarantee reliable delivery of data. The connection between the two ends is not consistent. Each datagram is sent and processed separately. There is no flow control, and each datagram can use different paths to reach the destination.

Potential Solutions to the problems in UNIX

If all sockets are set to be non-blocking, the process can execute a loop that analyzes each socket to see if there is something to be read. If it is available it handles it. If the data is not available it goes on a sleep mode until the next time the socket is scheduled to be checked. The polling process is inefficient because it consumed lot of CPU time.

The parent process can use fork () to create a child process for socket handling. This communication mechanism enables the processes to read from the port and block since the system will handle scheduling the processes most efficiently. However the child process must return to read data from the parent process via some other form of IPC. Asynchronous I/O functionality is not effective in UNIX since signals are very rare and expensive to catch. If more than one socket is using asynchronous I/O, there is a need to find out which socket the signal corresponds to.

Unix Email program can only send text messages. It does not support binary files for example images, word documents. For sending binary files other email programs can be used.

UNIX consists of two kinds of programs that handle emails:

User Agent: This program provides the interface and interacts with the users for sending and receiving emails. The message sending and retrieval is connected to the transfer agent.

Transfer Agent: This program does not interact directly with the user. It routes the messages to the required destinations.

Linux supports a command “Finger” which is used to see how many users are logged on to the system.

The command gives details as follows:

• User name,
• Full name of the person associated with the username,
• Terminal name,
• Login time,
• Machine from where he has connected on a specific system and idle time

Work Cited

Brooks, J. (2007). The future of desktop linux. EWeek, 24(37), 16-20.

Kennedy, M. (2010). Evaluating open source software. Defense AT&L, 39(4), 42.

Ohio supercomputing center to deploy hp linux supercomputer. (2002). UNIX Update, 13(12), 7.