Chapter 1 What is Unix ?

Objective  Effective use of Unix and Linux  command, shell programming, X-window,...  Unix system programming  file, process, network programming  Systematic understanding of Unix system

Motivation  Unix is a popular operating system  server systems(web server, db server,...)  Linux : free OS for PCs  research and development  engineering and business applications  System Programming  programming using OS support  using Unix system calls  file, process, IPC, networking, …  DBMS, compiler, groupware, debugger, …

Linux 와 다른 운영체제와의 비교 윈도우 NT 윈도우 98 리눅스 웹 서버무료사용 않음무료 메일 서버무료사용 않음 무료 파일 서버유저당 사용 않음 무료 라이선스 프린터 서버무료사용 않음무료 PC 통신가능가능가능 인터넷가능가능가능 문서 작성가능가능가능 프로그래밍유료 컴파일러유료 컴파일러무료 컴파일러 게임많지 않음많음많지 않음

왜 리눅스를 사용하는가 ?  무료이기 때문  배포판 : RedHat 7.2, AlzzaRedhat 6.1, MiziLinux 6.1, …  풍부하고 다양한 하드웨어를 효과적으로 지원  대부분의 하드웨어를 지원하는 추세임  인터넷에 맞는 강력한 네트워크 구축  윈도우 98/NT 와 통신 가능 ( 삼바 )  Netware 서버 에뮬레이션  놀라운 성능 및 안정성  486 으로도 충분히 빠르며 안전하게 수행  다양한 응용 프로그램 개발 중

History and Standards  Developed at AT&T Bell Lab  by Ken Thompson in assembly language  written in C by D. Ritchie  portable only if C compiler is available  sources code was understandable and open at universities  BSD UNIX  improvements at U.C. Berkeley  first good memory management  first networking

History and Standards  Linux  Started by Linus B. Torvalds at Univ. of Helsingki  an efficient Unix system for PC  extended by volunteers on Internet  free OS on public domain  platform  Intel PC, DEC Alpha, Sun SPARC,...  Distribution with GNU software  Slackware  RedHat 7  AlzzaRedHat 6( 한글 Linux), MiziLinux 6

Versions of UNIX  UNIX today  UNIX System V at AT&T Bell Lab.  BSD UNIX at U.C. Berkeley  Sun OS, Sun Solaris  integration of System V and BSD  IBM AIX, HP UX, Cray Unicos,...  Linux for PC  UNIX tomorrow  parallel distributed processing  object-oriented programming

Features of Unix  Simple and portable  against MULTICS at MIT  written in C  multi-user and multi-process operating system  many users can access a system at the same time  super-user for administration  many programs in execution at the same time  Shell programming  using utilities and pipeline mechanism  % who | sort  like batch files in MS-DOS

Features of UNIX  Portable on a wide variety of platforms  LINUX on PC  Sun OS on Sun Workstation  AIX on IBM RS Workstation  Unicos on Cray  Consistent view of resources  directory hierarchy, files, devices, …  Excellent networking  ftp, web, X-window,  client/server computing, many open software on internet,