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A UNIX "process" is an instance of a running programListing Process : ps, top{$ topSystem: vm189 Thu Jun 22 17:28:09 2017Load averages: 2.54, 2.72, 3.67214 processes: 149 sleeping, 65 runningCpu states:CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS 0 2.66 0.2% 99.2% 0.6% 0.0% 0.0% 0.0% 0.0% 0.0% 1 2.41 1.8% 96.4% 1.8% 0.0% 0.0% 0.0% 0.0% 0.0%--- ---- ----- ----- ----- ----- ----- ----- ----- ..

PipelinesThe | symbol is used for linking two commands together. A | B | C [commands B must be filter]{$ who | wc -l14$ who | dateThu Jun 22 12:12:12 KST 2017$ ps -ef | more$ ls | sort -r | more$ ps -ef | grep telnetd$ ps -ef | grep telnetd | wc -l} Pipelines versus Input and Output Redirectionwho > sort.out, sort stdin..

Input and Output Redirection Introducestdin : 표준입력 0 (file descriptor)stdout : 표준출력 1stderr : 표준오류 2 Input Redirection (create, overwrite) , >>(create, append)$ date > date.out$ cat date.outThu Jun 22 10:23:14 KST 2017 $ id > date.out$ cat date.outuid=311(user11) gid=301(class) groups=302(class2)$ cat date.outuid=311(user11) gid=301(class) groups=302(class2)Thu Jun 22 10:25:30 KST 2017 $ cat > c..

Quoting Introduce Many characters have 'special' meaning to the shell : white space, carriage return, $, #, *, Quoting removes the special meaning of the special characters:eg) rm='rm -i', MYNAME="YO HAN" Quoting - back slash (\)$ color=red\ white\ and bluesh: blue: not found.$ color=red\ white\ and\ blue$ echo $colorred white and blue$ echo one two \ //carriage return >one two Quoting - ' , ..

? : Matches any single character except a leading dot ( ?, except dot, .?, include hidden file)[ ] : a class of characters from which one will be matched{$ echo [abc]??$ echo [1-9][A-Z]$ echo [!A-Z]??}- :! :* : Matches zero or more characters except a leading dot ( ?, except dot, .?, include hidden file){$ echo .*$ echo *.dat contain only five character : echo ?????contain at least five characte..

Shell Variable Storage : Local Variables + Environment Variables + Program Code (/usr/bin/sh){$ name=yohan$ set...name=yohan....} Variable Substitution$var : Directs the shell to perform variable substitution{$ echo $PATH/usr/bin:/usr/contrib/bin: ...$ PATH=$PATH:$HOME/usr/bin: .... :/home/user11}Command Substitution$(command) Process and Variable (Parent Child)1 fork : program and data spaces a..

$ ps PID TTY TIME COMMAND 12608 pts/tg 0:00 telnetd 13471 pts/tg 0:00 ps 12609 pts/tg 0:00 sh frankenstein command history : command "history" recalling commands : Press "ESC", k scrolls backward through the command history, scrolls forward through the command history [then, work as command mode] env : environment describes your session to the programs you run set : describes your local variable..

vi "filename" : start a vi edit session of file cursor, line, page moveh, j, k, l. ctrl + b, f.("command mode") + ":" + "( )" + "Return""wq" (write and quit)"q" (quit)"q!" (force quit)"w" (write) vi Modescommand mode : keystrokes intepreted as commandsinput mode : vi input with keystrokes entered into the file ( from command mode -> "i, a, o, I, A, O" )last line mode : ex and search inputs ( fro..

access typeOwner, Group, Other-rwxrwx--- 1 user11 class 141 Nov 13 1993 prog1-rw-rw---- 1 user11 class 29 Nov 13 1993 yourfile/ow//gr//ot/ owner group ... and other FilesRead : Contents can be examined [cat filename]Write : Contents can be changed [vi filename]Execute : File can be used as a command { eg) $ cat myprog# this is the program myprogdatels -F$ myprogTue Jun 20 12:51:41 KST 2017README..

/opt (optional) : application (C:\Program Files)/usr (user) : commands & commands information/usr/bin (binary / .exe) : Contains the programs for all reference manual selction 1 commands, which are neccessary for basic UNIX system operation and file manipulation/usr/sbin (superuser binary) : Contains system administration commands/usr/lib : contains archive and shared libraries used for applicat..