unix

OPERATING SYSTEM

UNIX Operating system

Q.1 Explain UNIX?

·        UNIX is a CUI Operating system.

·        Unix is a multiuser, multitasking operating system..

·        Developed at Bell labs in the early1970s.

·        It was designed to be small, flexible, system used exclusively by programmer.

·        UNIX was the one of the first operating system written in High Level Language namely C. This meant that it could be installed on compiler existed.

·        Because of its low cost it is too popular in school and University.

·        By the end of 1970s, dozens of different versions of UNIX were running at various sites.

·        After its breakup in 1982, AT &T began to market UNIX in earnest.

·        Because of its portability, flexibility and power UNIX has become a leading operating system for workstation.

·        Popular versions of UNIX are {UNIX 03, UNIX 95, and UNIX 93}.

Q.2 Explain advantage of UNIX operating system?

·        Full multitasking with portable memory.

·        Multiple users can run multiple programs each at the same time without interfacing with each other or crashing the system.

·        Very effective virtual memory.

·        All users must enter his/her own user name and password for login.

·        All files are owned by particular accounts.

·        File owner can decide to whom other can read write file or not.

·        Full command based.

·        Fast and powerful.

·        This was the first operating system created on High level programming language.

Q.3 Why UNIX better than other?

·        Excellent use and control of system resources than other.

·        Very high reliability (long time run without reboot).

·        Tools for customizing the system are either native or bundled with the operating system or are easily available free.

·        For better stability than any other operating system, save (maybe) for mainframe system.

·        Varity of free software are available for UNIX operating system.

·        UNIX system can operate continuously for hundreds of days without being rebooted. There have been many cases of UNIX servers that have run for years continuously. And in Windows NT recommended reboot NT server every month.

·        Power full command line interface (the shell).

Q4. File security in UNIX?

·        File security within UNIX is based on 9 permission bits, set user and group ID bits, and the Sticky bit for a total 12 bits. These permissions apply almost equally to all file system objects such as files, directories and devices.

·        Only the owner user of file can decide who can read/write file.

·        UNIX assigns file permission to three broad categories-:

ü The user that owns the file.

ü The group that owns the file.

ü Every one other own this file

·        Each permission categories assign the three permission.

ü (r)ead

ü (w)rite.

ü E(x)ecute.

Q5. UNIX VS WINDOWS?

 UNIX                                                                                                   WINDOWS

·        UNIX IS free.                                                                           * Windows is costly.

·        UNIX security is better.                                                        * Windows is not secure as UNIX.

·        UNIX has better control on Multiuser                               * Windows is not better as UNIX.

and multitasking.

Q6. UNIX VS DOS?

·        UNIX is multiuser .-                                                   * DOS is single user.

·        Unix support multiprocessing. .-                            *Dos is single process.

·        Unix has its own shell. .-                                          *Dos has its own command prompt.

·        UNIX has user name / password. .-                       *Only some version of dos support

For login and user/ group permission. .-                 file protection.                                   

·        UNIX has shell script. .-                                            *Dos has Batch file.

·        Unix is widely run on all processor. .-                     * dos work on Intel processor 8088,

                                                                                          8086, 286, 386, 486 Pentium.

Q7. UNIX VS LINUX?

·        UNIX is CUI.                                                              * LINUX is GUI.

·        UNIX is mother of LINUX                                       * LINUX IS based on UNIX.

·        UNIX is faster than LINUX                                     * LINUX is not faster as compare to UNIX.                                                                    

Q8. User management in UNIX?

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