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70 Cards in this Set
- Front
- Back
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Main services of OS
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Execution of program
Input and output operations Communication between programs Error detection and reporting Manipulation of all types of files Management of users and security "Efficiently" and "securely" |
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Five popular flavours
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AIX, BSD, Linux, HP-UX, Solaris
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Determine which unix system is being used
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uname
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Immediate predecessor of UNIX
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MULTICS
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Main Branches
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USG , Bell labs and BSD
USG -> SystemV Bell Labs -> Linux |
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Why was UNIX accepted
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ever evolving OS that was used widely
useful in a variety of applications open source community |
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Set an environment variable
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LINES=25
export LINES |
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Command to fide a program
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whereis
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5 environment variables
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HOME
PATH PWD TERM |
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Pico commands to
Save, Read |
CTRL-O (WRITEOUT)
CTRL-R (READ) CTRL-K (COPY) CTRL-U (PASTE) |
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vi Replace all instances of dude with dude2
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1,$s/dude/dude2/g
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vi copy & paste
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y2W, 4yb, y
p 5p |
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Emacs Save
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Ctrl-X + Ctrl-S
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Emacs Copy, Paste
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Esc W
Ctrl Y |
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Emacs search and replace
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query-replace
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Create / Delete Directory
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mkdir
rmdir -p makes parent directories |
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Display File Types
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file
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Where are file # stored
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per process file descriptor table
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Where is user/group information
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/etc/group
/etc/passwd |
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Change file permissions:
owner everything group read everyone nothing |
chmod u=rwx,g=r,o=
chmod u+rwx chmod 740 |
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set default permission
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umask 022 (defaults to 755)
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list options
directories long all |
ls -
d l a |
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display the contents of a file
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cat
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display the contents of a file with line numbers
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cat -n
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page starting 2 lines before the word lorenb
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more +/lorenb
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Last five lines of a file
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tail -5 file
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copy command
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cp
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move command
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mv
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delete command
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rm
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copy, move, delete options
preserve permissions, timestamps recursive force overwrite of files prompt overwrite |
p
r f i |
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File differences
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diff file1 file2
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Print a document
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lpr #5 -P PRINTERNAME file
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Printer status
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lpq
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Remove job from printer
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lprm
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Printer commands for System V
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lp, lpstat, cancel
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Get the number of bytes in a file
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wc -c file
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Get just unique records
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uniq
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zip file
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gzip file
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list a gzip file
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gzip -l file
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unzip file
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gunzip file.gz
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display uncompressed contents of compressed file to screen
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zcat
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sorting a table by second column
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sort +1 file
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select fields 2 and 3 from a file
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cut -f3,4 file
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join two tables
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paste
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find some file whose size > 1000 bytes
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find / -size +1000c
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Encrypt a file
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crypt 44444 < file > file.crypt
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decrypt a file
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crypt 44444 < file.crypt > file
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does a hard link share an inode
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yes
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disadvantages of hard link
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can not span devices
only allowed by superusers files deleted and replaced are lost |
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Command to create a hard link
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ln file file.hard
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Command to create a soft link
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ln -s file file.soft
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make a fifo
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mkfifo fifo 1
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delete fifo
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rmfifo fifo1
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5 ways to share files
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copy them
common login share a users directory (permissions) common group Links |
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5 UNIX Process states
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ready
running waiting swapped zombie |
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priority methods
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FCFS
RR |
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list processes
- hide leaders - for a user |
ps
-a -u 147 |
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5 TCP/IP Layers
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Device
Link Network Transport Application |
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return the name of the host
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hostname
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display who is logged into a server
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rwho servername
rusers servername |
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remote copy
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rcp ~/file server:file
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Make an already defined variable readonly
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readonly variable
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remove a variable
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unset variable
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split a variable into argument list
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set something and something else
$1 $2 $3 $4 |
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Command to create an archive
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ar r file fiel file
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Old way of creating a source control file, checking in and out
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admin -ifile.c s.file.c
get s.file.c unget s.file.c delta s.file.c |
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New way of creating source ctrl file
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sccs create input.c
co input.c ci input.c rlog |
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5 components of hardware
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primary storage, CPU, secondary storage, io devices, bus
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6 unix layers
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device drivers
kernel system call interface language libraries unix shell applications |
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4 kernel functions
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file mgmt
storage mgmt process mgmt IPC CPU scheduler |
