prof. navrati saxena ta: rochak sachan
TRANSCRIPT
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Purpose of essential utility Locating system information For better file management organizing your data System administration etc…
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Create two file using text editor(vi,cat….)
First file name as : sname
Second file name as: smark
Example:
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$vi sname.txt S.ID Name ------------------------------- 11 Park 12 Lee 13 Kim 14 Won 15 Nam
$vi smark.txt S.ID Mark ------------------------------- 11 82 12 98 13 90 14 85 15 75
F1 F2
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Purpose to select any field of file Use cut command Select field using –f option (like : -f1 , -f2) Syntax:
cut -f{field number} {file-name} Example:
$cut -f2 sname ▪ It will print only F2 field(name)
$cut -f1 sname ▪ It will print only F1 field(S.ID)
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Use cut utility using redirection symbol(>)
$cut -f2 sname > /tmp/sn.tmp.$$
$cut -f2 smark > /tmp/sm.tmp.$$
$cat /tmp/sn.tmp.$$
$cat /tmp/sm.tmp.$$
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Park
Lee
Kim
Won
Nam
82
98
90
85
75
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Paste utility join textual information together.
Use paste command Syntax:
paste {file1} {file2}
Example
$ paste sname smark
$ paste /tmp/sn.tmp.$$ /tmp/sm.tmp.$$
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The join utility joins, lines from separate files.
Work only if common field have in both file Syntax:
join {file1} {file2}
Example
$join sname smark
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Use to translate range of characters into other range of characters.
Syntax: tr {pattern-1} {pattern-2}
Example: $ tr "h2" "3x" < sname
▪ each occurrence of character 'h' is replace with '3' and '2' with 'x‘
▪ translate specific characters into other specific characters or range of characters into other ranges. ▪ h -> 3
▪ 2 -> x
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$ tr "h2" "3x" < sname
11 Park 1x Lee 13 Kim 14 Won 15 Nam
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tr translate range of characters (i.e. small a to z) into other (i.e. to Capital A to Z) ranges.
Another example:
$ tr "[a-z]" "[A-Z]“
▪ after executing command type text in lower case like:
For terminate this program press ctrl+c
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$ tr "[a-z]" "[A-Z]"
hi i am park
HI I AM PARK
what a magic
WHAT A MAGIC
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To manipulate data. Syntax:
awk 'pattern action' {file-name}
Example:
Create any file like ‘computer’
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$vi computer.txt
Keyboard order 4
Memory good 10
Mouse okay 4
Printer good 12
Floppy good 5
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Use following command
$ awk '/good/ { print $3 }' computer
▪ This command will print third field which is containing ‘good’ word like:
Try one more command
$ awk '/good/ { print $1 }' computer
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10
12
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Editing file without using editor Edit file or may be input from a pipeline Syntax:
sed {expression} {file}
Example:
Create a file using ‘vi’ or ‘cat’
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$vi ipadorgalaxy
Samsung galaxy is good.
Apple ipad is good.
galaxy is better than the ipad.
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Use following command: $ sed '/galaxy/s//ipad/g' ipadorgalaxy >
/tmp/result.tmp.$$
$ cat /tmp/result.tmp.$$
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Removes duplicate lines Synatx:
uniq {file-name} Example:
Create any file like :
Try following command: ▪ uniq myinfo
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$vi myinfo
Hello,
My name is Kim Sung
My ID is : 2011111777
2011111777
I am from SungkyunKwan University.
SungKyunKwan students are very good.
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To find matching pattern or word Syntax:
grep "word-to-find" {file-name} Example
Create any file
Try following command ▪ $ grep "too" demofile
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$ vi demofile
hello world!
cartoons are good
especially toon like tom (cat)
what
the number one song
12221
they love us
I too
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Richard Petersen; "The Complete Reference,
Linux, Fourth Edition", Osborne/McGraw-Hill,
Christopher Negus; "Linux Bible, 2007 Edition", Wiley Publishing, Inc
http://www.freeos.com/guides/lsst/ http://bash.cyberciti.biz/guide/Main_Page
rochak @skku.edu