PROGRAM-3
SESSION-1
a.
Login
to the system.
b.
Use
the appropriate command to determine your login shell.
c.
Use
the /etc/passwd file to verify the result of step b.
d.
Use
the who command and redirect the result to a file called myfile1.use the more
command to see the contents of myfile1.
e.
Use
the date and who commands in sequence (in one line) such that the output of
date will display on the screen and the output of who will be redirected to a
file called myfile2. Use the more command to check the contents of myfile2.
Source
code:
I.
Enter
userid and password as student.
II.
To
determine the shell, use
echo
$0àbash (Bourne
again shell)
echo
$SHELLà/bin/bash
(path)
III.
Type
to verify the result of step II type:- cat /etc/passwd
Student:
X: 500: 500: student: /home/student: /bin/bash
Description
of the above statement:-
Studentàusername
Xàpassword which is encrypted form.
500àuserid (range: 0-65535)
500àgroupid (range: 0-65535)
0àsuper user. We cannot create super user. It is created by
administrator during installation of OS.
Studentàowner of the system.
/home/student:àhome directory
/bin/bashàtype of shell.
IV.
Type
“who”
Student
pts/0 2015-02-05 16:01(:0.0)
Description
of the above statement:-
Studentàsystem name
Ptsàpseudo terminal slave in which terminal (or) to display
how many terminals are working on.
2015-02-05àdate
16:01àtime
- To redirect
the result to a file called myfile1, type: - who >myfile1.
- To display the
content, we can use “cat myfile1”. But “cat” displays only last 26 lines
and the remaining result should be scrolled.
- Therefore, by
using more command “more myfile1”. It displays page wise with percentage.
V.
To
display the date, type date and press enter.
Thu
Feb 5 16:09:23 IST 2015
To
display the output of date and who command in sequence,
date;who
Thu
Feb 5 16:09:23 IST 2015
Student
pts/0 2015-02-05 16:01(:0.0)
To
display the output of date and the output of who command is redirected to
myfile2 type:-
date;who
>myfile2
Thu
Feb 16:09:23 IST 2015
To
display “who” in myfile2.type “cat myfile2”
Student
pts/0 2015-02-05 16:01(:0.0)
SESSION-2
a.
Write
a sed command that deletes the first character in each line in a file.
Source code:
Create myfile1 using cat as “cat >myfile1”
Type some text like:
Welcome to
unix
Welcome to gvp
To delete the first character in each line type,
sed ‘s/^.//’
myfile1
elcome to unix
elcome to gvp
No change in file but only change in output
cat
myfile1
Welcome to unix
Welcome to gvp
b.
Write
a sed command that deletes the character before the last character in each line
in a file.
Source code:
Create a file using cat as “cat >file1”
Type some text like:
Welcome to
unix
Welcome to gvp
To delete the last before character in each line in a
file type,
sed ‘s/.\ (.$\)/\1/’ file1
Output:
Welcome to unx
Welcome to gp
c.
Write
a sed command that swaps the first and second words in each line in a file.
Source code:
Create a file using cat as “cat >file”
Type some text like:
welcome to unix
welcome to gvp
To swap the first and second words in each line in a file
type,
sed ‘s/\([a-z]*\) \([a-z]*\)/\2 \1/’
Output:
to welcome unix
to welcome gvp
PROGRAM-4
b. Develop an interactive grep script that asks for a
word, file name and then tells how many lines contain that word.
Source
code:
cat
>abc.txt
harika
pravallika
nikhitha
pravallika
pravallika
echo
“enter a word:”
read
word
echo
“enter a file name:”
read
file
echo
“No. of. Times $word is present in $file”
grep –c
$word $file
Output:
enter a
word:
pravallika
enter a
file name:
abc.txt
No. of.
times pravallika is present in abc.txt
3
PROGRAM-5
a.
Write
a shell script that takes a command-line argument and reports on whether it is
directory, a file, or something else.
Source code:
echo
“Enter file:”
read
str
if
test –f $str
then
echo “file exists and it is an ordinary file”
elif
test –d $str
then
echo “it is a directory file”
else
echo
“no such directory (or) file exists”
fi
if
test –c $str
then
echo “character device file”
fi
Output:
Enter
file:
f1
file
exists and it is an ordinary file
b.
Write
a shell script that accepts one or more file name as arguments and converts all
of them to upper case, provided they exist in the current directory.
Source code:
echo
“Enter file:”
read
str
if
test –f $str
then
echo “file exists and it is an ordinary file”
tr
‘[a-z]’ ‘[A-Z]’ <$str
fi
Output:
cat
>pravs.txt
welcome
to unix
welcome
to gvp
Enter
file:
Pravs.txt
File
exists and it is an ordinary file
WELCOME
TO UNIX
WELCOME
TO GVP
PROGRAM-7
a.
Write
a shell script that computes the gross salary of a employee according to the
following rules:
àIf basic salary is < 1500 then HRA=10% of the basic
and DA=90% of the basic.
àIf basic salary is >= 1500 then HRA=Rs. 500 and DA=98%
of the basic.
Source
code:
echo “enter the basic salary:”
read
basicsal
if
[ $basicsal –lt 1500 ]
then
hra=`expr
$basicsal \* 10 \/ 100`
da=`expr
$basicsal \*90 \/ 100`
else
hra=`expr
$basicsal + 500`
da=`expr
$basicsal \* 98 \/ 100`
fi
gross=`expr
$basicsal + $hra + $da`
echo
$gross
Output:
enter
the basic salary:
1300
2600
enter
the basic salary:
1700
5566
b.
x=$1
y=$2
z=1
i=1
if
[ $# -eq 0 ]
then
echo “no arguments”
else
while [ $i –le $y ]
do
z=`expr $z \* $x`
i=`expr $i + 1`
done
fi
echo
$z
Output:
sh
f112.sh 2 3
8
sh
f112.sh
no
arguments
1
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