1 / 16

UNIX & file system

UNIX & file system. cosc513 Deyong Xu ID:103816 Nov.9 2000. What is Unix. A computer operating system that works with users to run programs, manages resources,and communicates with other computer system. Unix Characters. Multitasking Multiuser Multichoice Portability.

erin-scott
Download Presentation

UNIX & file system

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. UNIX & file system cosc513 Deyong Xu ID:103816 Nov.9 2000

  2. What is Unix A computer operating system that works with users to run programs, manages resources,and communicates with other computer system.

  3. Unix Characters • Multitasking • Multiuser • Multichoice • Portability

  4. Multitasking • Users can run several programs at the same time , such as editing a file while their another program is running on the backstage . • Users don’t have to wait for one application to end before starting another one.

  5. Multiusers • Multiple users can log on unix system at the same time. • Unix can take the commands of a number of users to run program, access file, and print documents at the same time which means a number of users can share computer resources simultaneously with each user running a different program .

  6. Multichoice • Unix has three different types of shell. • Shell is to act as an interpreter between the user and the computer. • Bourne Shell. • C Shell . • Korn Sell.

  7. Portability • Unix can be moved from one brand of computer to another with a minimum of code change • Unix can be upgraded without having all the customer’s data inputted again • Decrease the user’s learning time when moving from one system to an other . • Provide more choices among the hardware vendors

  8. UNIX File System 3 types of unix files • Regular files • Programs and data files • eg: • Source code of a program • Email received from friend • Executable programs and applications

  9. Continue … • Directory files • Basic management tools in UNIX file system • Files that contain other files • Save information of files (like size,location etc.)

  10. Continue … • Device files • Each hardware is treated like a file • Eg1 : Terminals,Printers, Keyboards, etc • Eg2:Read from a keyboard device file(input). • Eg3:Copy the file to the printer device file(print).

  11. File System Architecture • A bottom-up tree with root on the top • Root (/), a special directory file

  12. Root (/) bin/ dev/ etc/ usr/ ... Xdy/ wjj/ lgx/ A Example

  13. 3 Classes of Users • Owner: used by user • Group : shared by group members • Other : shared by any user

  14. File Three Permissions • Read permission: read 1/0 • Write permission: modify, delete 1/0 • Execute permission: run 1/0

  15. Example: permission of the file is (111 101 000)

More Related