unix 02

8/13/2019 Unix 02

1/25

UNIX Day 2

Intermediate Level

8/13/2019 Unix 02

2/25

2

Recap Day 1

Introduction to UnixUnix System ArchitectureBasic Unix Commands

File and directory related commandsShell meta charactersStandard files

Redirection and Pipe

8/13/2019 Unix 02

3/25

3

Session Plan Day 2

Text Processing Commands

Process Related Commands

Memory Related CommandsCompression Utilities

8/13/2019 Unix 02

4/25

Text Processing Commands

8/13/2019 Unix 02

5/25

5

Command Description Syntax

paste Combines the content of the files

line by line Prints the files content horizontally

$ paste file1 [file2]

head Displays a set of lines of the given

data from start$ head [-n] file_name

tail Displays a set of lines of the givendata from last $ tail [ n/+n] file_name

wc Displays total no of lines, words andcharacters in any data $ wc [ lwc] file_name

Text Processing Commands (1/7)

8/13/2019 Unix 02

6/25

6


tr Translate characters Used on output of some other

command

$ cmd_output | tr [option]src_charset tar_charset

Variations Syntax/Sample Example

Squeeze the character $ ls l | tr s

Squeeze and translate the characters $ ls l | tr s #

Translate the characters $ date | tr #


8/13/2019 Unix 02

7/257


cut

Retrieves specific fields orcharacters from the data Used on output of some other

command or file content

$ cmd_output | cut[option] $ cut [option] file


Retrieve specific character set $ cat file1 | cut c5$ cat file1 | cut c5-10

Retrieves specific field set

$ date | cut d f3

$ date | cut d f3,5-d: for delimiter-f: for field number


8/13/2019 Unix 02

8/258


sort

Used to order the data Used on output of some other

command or file content Default sorting is as per the

English dictionary

$ cmd_output | sort[option] $ sort [option] file


To sort in reverse order $ sort r file1

To remove duplicate data $ sort u file1

To apply numerical sort $ sort n file1

To merge the content of two or more files $ sort m file1 file2


8/13/2019 Unix 02

9/259


grep Pattern search in the given data Global Regular Expression Parser $ grep [option] pattern data

Variations SyntaxIgnores case while searching $ grep i pattern file_namePrints only the count of the number of lines,having given pattern $ grep c pattern file_name

Prints the lines which are not containing

given pattern$ grep v pattern file_name


8/13/2019 Unix 02

10/2510

Matching for lines SyntaxPrints lines starting with any pattern $ grep ^pattern file_name

Prints lines ending with any pattern $ grep pattern$ file_name

Anchor Characters for grep Command

Matching for words Syntax

Defining the boundary of the words This will match only alphabetic and numeric characters

Prints the lines which are containing word

starting with any pattern$ grep \file_name

Prints the lines which are containing givenpattern as whole word $ grep \file_name

8/13/2019 Unix 02

11/25

11


uniq Removes adjacent repeated lines inthe given data $ uniq [option] data

Variations SyntaxRemoves adjacent repeated lines and printsthe output $ uniq file_name

Prints only uniq lines $ uniq u file_name

Prints only duplicate lines $ uniq d file_name


8/13/2019 Unix 02

12/25

12


cmp Used to compare two files Pinpoints only the first difference

between two files$ cmp file1 file2

comm

Used to compare two files Can be applied only on sorted

files Give the result in three columns:

First column: Data unique to firstfileSecond column: Data unique to

second fileThird column: Data common inboth the files

$ comm file1 file2


8/13/2019 Unix 02

13/25

13

Self Study: Text ProcessingCommands Demo

8/13/2019 Unix 02

14/25

14

Can you answer these questions?

What should be the command:To count the number of directories and filespresent in the current working directoryTo count the number of blank lines (lines without

text) in a fileTo display the first 8 lines from a fileTo display only the 4 th line from a file

Differentiate betweencat file1 file2 file3 & paste file1 file2 file3

8/13/2019 Unix 02

15/25

Process and Memory relatedCommands

8/13/2019 Unix 02

16/25

16

Process related Commands

A process is a program in execution

Each process is allocated a process identifier

or PID

In general, each process is started by another,

known as parent process.

So every process is also have one parentprocess identifier or PPID

8/13/2019 Unix 02

17/25

8/13/2019 Unix 02

18/25

18

Command Description Syntax & important variations

nice Execute a command withupdated scheduling priority $ nice [option] [command]

nohup

Executes the command in

background even after log outfrom the session $ nohup command

kill Used to send a signal to aparticular process$ kill [signal_info] PID$ kill [signal_info] %JobID

Process related Commands (2/2)

8/13/2019 Unix 02

19/25

19

Command Description Syntax & important variations

df Prints file system disk spaceusage $ df [FILE]

du Estimates file space use $ du [FILE]

Memory related Commands

df command du commandIt will display the information about theblocks of different file systems installed

on our system.ORIt will give the information about inwhich particular file system thespecified file or directory is available.

It will display the block used by all thedirectories and sub-directories availableunder the present working directory.ORIt will display the block used by thespecified file or directory.

8/13/2019 Unix 02

20/25

Compression Utilities

8/13/2019 Unix 02

21/25

lf d l

8/13/2019 Unix 02

22/25

22

Self Study: Compression UtilitiesDemo

8/13/2019 Unix 02

23/25

23

Can you answer these questions?

Differentiate between bg and fg commands.Differentiate between df and du commands.Harry has a directory named Dir1 containing 872files. James wants to use Dir1. How will Harry sendthis through mail to James?

8/13/2019 Unix 02

24/25

24

Summary

Text Processing Commands.Process related CommandsMemory related CommandsCompression Commands

8/13/2019 Unix 02

25/25

2525

Thank You

unix 02

Documents