Hi,
Kindly tell me, Is there any concrete reason behind selecting Linux as a major OS for study instead of Windows because, most of us has windows already installed and we are also familiar with it, please explain.
Also tell me what is FILE DESCRIPTOR TABLE?
What type of information it contain?
Hello my name is John Sena and I am a Master of Computer Sciences. During my studies I also faced that types of problems but I studied different types of books and got their answers. Ok now the answer of your question is that Yes. Linux is open source. You have complete code of Linux operating system whereas in Windows you do not have the privilege to see its code. While programming in C in the Linux environment you get a better understanding of the OS concepts.
And the other part of you question is that A File Descriptor table is created for each process. It is used to locate the relevant data of that process on the disk and is indexed by an integer value called as File Descriptor. Basically, each entry of file descriptor table contains a flag and a pointer. Pointer helps in traversing the file and node tables.
Hi there!
There are many reasons behind selecting Linux as a major OS for study instead of windows as well as there are disadvantages. Firstly, let me site to you some disadvantages to using the Linux operating system.
1. Cost – It cannot be denied that one sure advantage of Linux is that, it is free to get hold while Microsoft products can be availed with certain fee and usually Microsoft licenses are only permitted for installation on a single PC while dissemination can be availed on any number of PC without any penny incurred.
2. Security – With regards to costs, the security condition of Linux is a lot more durable than that of Windows. I cannot think of any reason why you should spend extra monetary fund for virus protection software? The Linux OS has been around ever since in the early nineties and has administered to stay protected in the domain of rampant viruses, spyware and adware for so many years. Definitely, the disagreement of the Linux desktop not being so popularly used is a component as to why there are no viruses. A counter argument is that the Linux operating system is open-source and if there were a rampant Linux virus released at present, there would be enormous number of patches released tomorrow, either by common people that use the operating system or by the distribution sustainers. We would not need to pause for a time for a patch from a single company like how we process with Windows.
2. Freedom of Choice – The freedom of choice plays a vital role in Linux advantage. With Linux, the capability to control about all condition of the operating system. There are two very important elements you have access to control of are your desktops look and feel in line with numerous window manager, and the kernel. At Windows, your either stuck utilizing the boring default desktop theme, or exposing corruption or failure by installing a third-party shell.
3. Software – So many software preferential or choices when i doing any required task. Either you search for a text editor on Freshmeat and yield hundreds, or if not thousands of results. In article on 5 Linux text editors should know about illustrated how come there were so many options for just editing text on the command-line expected to the open source nature of Linux. Frequent users and programmers promoted applications any time. Occasionally a feature enhancement of an existing piece of software, sometimes its a brand new application. Software on Linux contributes to be packed with greater features and greater usability than software on Windows. Best of them all, the extensive majority of Linux software is free and open source. You don't only get the software for free, but you have the option to modify the source code and add more features if you comprehend the programming language.
4. Hardware – Old computers perfectly suits Linux with hardly any processing power or memory you have sitting in your garage or basement collecting dust. There are endless possibilities in the installation of Linux and using it as a firewall, a file server, or a backup server. The vintage 386 or 486 computers with barely any RAM operates Linux without any issue problem.
Secondly, the disadvantages of Linux::
1. Understanding – As you become familiar with the Linux operating system, it requires your patience as well as a strong learning curve. It also requires you to have the desire to search and read, analyze and figure things out on your own, rather than having someone do the work for you.
2. Compatibility – For the reason that Linux is free, Linux is occasionally behind when it comes to brand new hardware compatibility. Though the kernel contributors and sustainers work closely at keeping the kernel updated, Linux does not have as much of a corporate support as alternative operating systems. More oftentimes you can find third party applications or none at all.
3. Alternative Programs – Even if Linux developers have executed a great job at promulgating alternatives to popular Windows applications, there are still ample applications that prevail on Windows that have no substitute Linux application.
Furthermore, Windows can be a great device for the inattentive and incompetent, but it takes an accurate scholar, one who wants to learn to run a vigorous operating system like Linux.
With regards to your other question inquiring about the File Descriptor Table is that it is an information that distinguish a file, giving details like its file name, generation number, date of last access, expiry date, and the structure of the records it contains. It is normally kept as a header record at the front of the file, held on magnetic tape or on disk. To elaborate the answer of your query, Each running process has a file descriptor table which consist pointers to all open i/o streams. When process starts, three (3) entries are initiated in the first three cells of the table. Standard input is entry 0 points and standard output is entry 1 points, for standard error is entry 2 points.
Whenever a file or the i/o stream is opened, a new entry is created in this table, commonly in the first available empty slot. The socket system call returns an access into this table example a small integer. This value is used or other calls which use this socket. The accept system call returns another access into this table. The value returned by accept is used for reading and writing to that connection. With this explanation, we hope you have obtained the necessary answers to your questions.
For the majority of operating systems, FD or File Descriptor is a small non-negative integer like 0, 12, or 567 which helps identify an open file within a process while using input/output resources such as pipes or network sockets. It is a number that uniquely identifies an open file in an operating system and describes a data resource and how that particular resource can be accessed.
When a program requests to open a file or another data resource like a network socket, for example, the kernel does the following:
At least one file descriptor exists for each open file on the system. FDs were first used in Unix and are used by modern operating systems like macOS, BSD, and Linux. In Microsoft Windows, FDs are called “file handles.”
