1) write a grep command to display all lines that begin and
end with same character.
à
create f1.txt file
Akash gupta
akilesh gupta
ankita
$ grep -i '^a.*a$' f1.txt
o/p:-
Akash gupta
akilesh gupta
ankita
2) Delete all leading and traling spaces in all line of a
file.
à
create file f2.txt
hi hello how
are you
tr -d '\ |' <
f2.txt
o/p:-
hihello howareyou
3)To print first three columns and first two rows of file.
à
create file f3.txt
rollno name result
1 akash gupta pass
2 jwala gupta pass
3 akilesh
gupta pass
4 ankita fail
$ head -n 2 f3.txt|cut -f 1-3
rollno name result
1 akash gupta pass
4) To print line numbers of all lines begins with ‘T’
in a file.
à
cat > f4.txt
the sachin is a good boy
he is male
grep -ni "^T" f4.txt
o/p:
1:the sachin is a good boy
5) To delete all lines begin with ‘T’ in a file.
à
grep -vi 'T' f4.txt
he is male
6)To display all lines that contains pattern g* in a line.
à
cat >f5.txt
god is great
he is a good boy
g* hello
grep "g\*"
f5.txt
g* hello
7)Count the frequency of each word in a text file.
à
cat f5.txt | tr -d [:punct:] |tr ' ' '\n'|tr 'A-Z'
'a-z'|sort|uniq -c|sort -rn
2 is
1 hello
1 he
1 great
1 good
1 god
1 g
1 boy
1 a
8) List all files of working directory having at last 4
characters in filename.
à
ls ????*
9) Replace multiple spaces with a space in file.
à
tr -s ' ' < f2.txt
hi hello how are you
10) Write a command to locate lines that begin and end with
a dot and containing anything between them.
à
cat > f10.txt
. hi hello .
hi
grep "^[.*.$]" f1
. hi hello .
11) Write a command to display all lines that contains 2 or
more ^
symbols at beginning of a file.
à
cat > f11.txt
^^^hello
hi
grep -n ^["'^^'*"] f11.txt
1:^^^hello
12) Write a command to display all filename containing only
digits in a filename.
à
ls | grep "^[0-9]"
o/p:
5KoH8dwx4jY.flv.part
13) Write a command to display lines 5 to 10,15-20, and last
lines of file.
à
cat > f13.txt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
unix
27
unix
28
$ sed -n -e '5,10p' -e '15,20p' -e '$p' f13.txt
o/p:
5
6
7
8
9
10
15
16
17
18
19
20
28
14) Write a sed command to extract first word of each line.
à
sed -n '1,$p' f5.txt | cut -d " " -f 1
god
he
g*
15) Write a command to display all line but not the last
line of file.
à
$ sed -n '$!p' f5.txt
god is great
he is a good boy
16) Write a command to display filenames of working
directory having first and last charater must be an alphabet.
à
ls | grep "^[a-z]"
17) Write a command to display all files having length
greater than equal to 10 characters.
à
ls | grep -e '[^\]\{10,\}'
18) To display those lines between 25 to 50 having pattern
‘unix’ in it.
à
sed -n '25,50p' f13.txt | grep -n 'unix'
3:unix
5:unix
19) To select files having read and write permissions for
all categories of users.
à
$ ls -l | grep -n '^-rw.rw.rw.'
20) To count number of characters on last line of file.
à
tail -1 f5.txt | wc -c
9
21) Display regular files having more than two links.
à
$ ls –l |cut –a “ “ –f |grep “2”
22) To count all lines that end with digits.
à
grep "[0-9]$" f1.txt | wc -l
0
23) Display those lines of the file in which third field
contain ‘director’ or ‘chairman’.
à
$ cat > f23.txt
eid ename desig
1 akash director
2 jayesh chairman
3 rahul manager
$ grep -e 'director' -e 'chairman' f23.txt | cut -f3
director
chairman
24) Write a grep command to display all files of current
directory that contains ‘unix’ pattern in it.
à
$ grep -l 'unix' f13.txt
f13.txt
25) To extract first word of each line of file.
à
$ awk '{print $1}' f5.txt
god
he
g*
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