II M.Sc Syllabus Computer Science Operating system Case study Linux Operating system UG

1. 1
Ex.No.1 UTILITY COMMANDS
Date:
AIM:
To execute the various basic,filedirectory handling and utility commands.
OUTPUT:
RESULT:
Hence the output is verified.

2. 2
Ex.No.2 SYSTEM VARIABLE
Date:
AIM:
To write a variable value type such as PATH,SHELL, HOST NAME and IFS etc.
PROGRAM:
echo $PATH
echo $HOME
echo $SHELL
echo $HOSTNAME
echo $IFS
OUTPUT:
RESULT:
Hence the output is verified.

3. 3
Ex.No.3 ADMINISTRATIVE COMMANDS
Date:
AIM:
To execute the various system administrative commands such as make directory, remove
directory and various list options.
OUTPUT:
RESULT:
Hence the output is verified.

4. 4
Ex.No.4 DISPLAY THE LIST OF USERS
Date
AIM:
To write a program to display the list of users currently logged in.
PROGRAM:
function line ()
{
echo “ ******* ”
}
echo “yours username: $ (echo $ user)”
line
echo “current date and time : $ (date)”
line
echo “ currently logged on yours: ”
who
line
OUTPUT:
yours user name:
******
current date and time:
thu mar 12 2020, 1.40pm
currently logged on yours:
mtnc lab4 ++y7 2020,1.40pm
********
RESULT:
Hence the output is verified.

5. 5
Ex.No.5 DISPLAY THE LIST OF USERS
Date
AIM:
To write a shell script that displays a list of all files in the current directory to which the user has
read ,write and execute permissions.
PROGRAM:
echo "enter the directory name"
read dir
if [ -d $dir ]
then
cd $dir
ls > f
exec < f
while read line
do
if [ -f $line ]
then
if [ -r $line -a -w $line -a -x $line ]
then
echo "$line has all permissions"
else
echo "files not having all permissions"
fi
fi
done
fi
OUTPUT:
RESULT :
Hence the output is verified.

6. 6
Ex.No.6 DELETE THE FILES
Date
AIM:
To write a shell script to delete all the temporary files.
PROGRAM:
rm -rf / tmp / *
rm -rf / var / tmp / *
fsck -A
exit
OUTPUT:
The file deleted.
RESULT:
Hence the output is verified.

7. 7
Ex.No.7 DISPLAY SOURCE CODE IN GIVEN FILE
Date
AIM:
To write the shell script that accepts a file name, starting and ending line numbers as arguments
and display all the lines between the given line numbers.
PROCEDURE:
1. Start
2. Get the filename.
3. Get the starting and ending line number.
4. Using -n and cat command.
5. Display the given lines of the files.
6. Stop.
PROGRAM:
echo "enter the file name"
read fname
echo "enter the starting line number"
read s
echo "enter the ending number"
read n
sed -n $s,$np $fname | cat > newline
cat newline
OUTPUT:
RESULT:
Hence the output is verified.

8. 8
Ex.No.8 DELETE A LINE CONTAINING SPECIFIED WORD
Date
AIM:
To write a shell script that deletes all lines containing a specified word in one or more files
supplied as arguments to it.
PROCEDURE:
1. Start.
2. Get the file names as command line arguments.
3. Write “enter the word to search and delete”.
4. Read word.
5. For each argument repeat step 6 to step 8.
6. if it is file then go to next step else display “error in file”.
7. Search the lines not contain specified “word”.
8. Write the above result into same file.
9. Stop.
PROGRAM:
if [ $# -eq 0 ]
then
echo NO ARUGUMENTS
else
pattern=$1
shift
for fname in $*
do
if [ -f $fname ]
then
echo DELETING $pattern FROM $fname
sed '/'$pattern'/d' $fname
else
echo $fname NOT FOUND
fi
done
fi

9. 9
OUTPUT:
RESULT:
Hence the output is verified.

10. 10
Ex.No.9 FILES OR DIRECTORY DOCUMENTS.
Date
AIM:
To write a shell script that receives any number of file names as its arguments, check if every
argument supplied is a file or a directory and reports accordingly. Whenever the argument is a file, the
number of lines on its to be reported.
PROCEDURE:
1. Start.
2. Get the file names and command line arguments.
3. Check the file is directory or file.
4. Display the number of lines in the file.
5. stop.
PROGRAM:
for x in $*
do
if [ -f $x ]
then
echo "$x is a file"
echo "no of lines in the files are"
wc -l $x
elif [ -d $x ]
then
echo "$x is a directory"
else
echo "enter valid filename or directory name"
fi
done

11. 11
OUTPUT:
RESULT:
Hence the output is verified.
Ex. No.10 .ARITHMETIC AND LOGICAL CALCULATIONS
Date:
AIM:
To write a simple shell script for basic arithmetic and logical calculations.
ALGORITHM:
1. Start the program.
2. Read the two numbers.
3. Perform the arithmetic operations for addition, subtraction, multiplication and division.
4. Compare the two variables ,to find the arithmetic and logical calculations.
5. Display the arithmetic and logical values.
6. Stop.

12. 12
PROGRAM:
#!/bin/sh
a=10
b=10
val=`expr $a + $b`
echo "a + b : $val"
val=`expr $a - $b`
echo "a - b : $val"
val=`expr $a * $b`
echo "a * b : $val"
val=`expr $b / $a`
echo "b / a : $val"
val=`expr $b % $a`
echo "b % a : $val"
if [ $a == $b ]
then
echo "a is equal to b"
fi
if [ $a != $b ]
then
echo "a is not equal to b"
fi
OUTPUT:

13. 13
RESULT:
Hence the output is verified.
Ex .No. 11.FACTORIAL OF THE GIVEN NUMBER
Date:
AIM:
To write a shell script to find the factorial of a given number.
PROCEDURE:
1. start
2. get the number as “num”
3. calculate the factorial number
4. display the number
5. stop
SHELL COMMAND:
echo "enter a number"
read num
fact=1
while [ $num -gt 1 ]

14. 14
do
fact=$(( fact * num ))
num=$(( num -1 ))
done
echo $fact
OUTPUT:
RESULT:
hence the output is verified.

15. 15
Ex. No.12. STRING OPERATIONS
Date:
AIM:
To write a shell script to perform various operations on given string.
PROCEDURE:
1. start
2. get two strings
3. to perform the string operation such as string compare, string length, reverse the string,
combine the string etc.
4. display the result string
5. stop
SHELL COMMAND:
clear
choice=y
while [ "$choice" = "y" ]
do
echo "____________________________________________"
echo "1. COMPARE TWO STRINGS"
echo "2. JOIN TWO STRINGS"
echo "3. FIND THE LENGTH OF A GIVEN STRING"
echo "4. OCCURRENCE OF CHARACTER AND WORDS"
echo "5. REVERSE THE STRING"
echo "6. EXIT"
echo "____________________________________________"
echo "Enter Choice: "
read ch
echo "____________________________________________"
case $ch in
1)
echo "Enter String1: "
read str1
echo "Enter String2: "
read str2
if [ $str1 = $str2 ]
then
echo "String is equal"
else
echo "String is not equal"
fi
;;
2)
echo "Enter String1: "
read str1

16. 16
echo "Enter String2: "
read str2
str3=$str1$str2
echo "Join String: " $str3
;;
3)
len=0
echo "Enter String1: "
read str1
len=$(echo "$str1" | wc -c)
len=`expr $len - 1`
echo "Length: " $len
;;
4)
echo "Enter String: "
read str
echo "Enter Word to find : "
read word
echo $str | cat > str1.txt
grep -o $word str1.txt | cat > str2.txt
count=`grep -c $word str2.txt`
echo "Count: "$count
;;
5)
echo "Enter String1: "
read str
len=`expr $str | wc -c`
len=`expr $len - 1`
while [ $len -gt 0 ]
do
rev=`expr $str | cut -c $len`
ans=$ans$rev
len=`expr $len - 1`
done
echo "Reverse String: "$ans
;;
6) exit ;;
*) echo "Invalid Choice ....." ;;
esac
echo "Do u want to continue.....? [y/n]"
read choice

17. 17
case $choice in
Y|y) choice=y;;
N|n) choice=n;;
*) choice=y;;
esac
done
OUTPUT:
RESULT:
Hence the output is verified.

18. 18
Ex. No.13 VOWELS CHECKING
Date:
AIM:
To write an awk script to find the number of lines in a file that do not contain vowels I (or) o
PROCEDURE:
1. start the program
2. to create the text file containing text with vowels and non vowels
3. read the file name (that is text)
4. check the words in the file not containing vowels
5. display the number of lines not containing vowels
6. stop
PROGRAM:
#!/bin/bash
echo "Enter file name"
read file
awk '$0!~/[aeiou]/{ count++ }
END{print "The number of lines that does not contain vowels are: ",count}' $file
OUTPUT:
new

19. 19
RESULT:
Hence the output is verified

20. 20
Ex. No.14. CHARACTER, WORDS AND LINE IN A FILE
Date:
AIM:
To write an awk script to find the number of character, words and lines
PROCEDURE:
1. start
2. get source file name
3. print character
4. print word
5. print lines
6. stop
PROGRAM:
echo Enter the filename
read file
w=`cat $file | wc -w`
c=`cat $file | wc -c`
l=`grep -c "." $file`
echo Number of characters in $file is $c
echo Number of words in $file is $w
echo Number of lines in $file is $l
OUTPUT:

21. 21
RESULT:
Hence the output is verified.

22. 22
Ex No.15 .BINARY SEARCH
Date:
AIM:
To write a shell script to search an element from an array using binary search
PROCEDURE:
1. Start
2. get the size of an array
3. get the elements one by one
4. get the target value
5. start with the middle element. If the target value is equal to the middle element of the array, then
return the index of the middle element. If not compare the middle with other value
6. when a match is found, print successful search
7. if no match is found, print unsuccessful search
8. stop the program
PROGRAM:
echo Enter array limit
read limit
echo Enter elements
n=1
while [ $n -le $limit ]
do
read num
eval arr$n=$num
n=`expr $n + 1`
done
echo Enter key element
read key
low=1
high=$n
found=0
while [ $found -eq 0 -a $high -gt $low ]
do
mid=`expr ( $low + $high ) / 2`
eval t=$arr$mid
if [ $key -eq $t ]
then
found=1
elif [ $key -lt $t ]
then
high=`expr $mid - 1`
else
low=`expr $mid + 1`
fi
done

23. 23
if [ $found -eq 0 ]
then
echo Unsuccessfull search
else
echo Successfull search
fi
OUTPUT:
RESULT:
Hence the output is verified

24. 24
Ex. No.16. FILE OPERATIONS
Date:
AIM:
To write a c program that takes one or more file/directory names as command line input and
reports the following information on the file.
A) file type
B) number of links
C)take of last access
D)read,write and execute permissions
PROCEDURE:
1. get the file name in the command line.
2. Display the node number
3. report the file or directory
4. display the number of link
5. display the time of last access
6. display the modification time
7. display the last change time
8. display the read,write and execute permissions
9. stop
PROGRAM:
#include<stdio.h>
#include<fcntl.h>
#include<sys/stat.h>
#include<time.h>
int main(int argc,char *argv[])
{
char *at,*mt,*ct; struct stat buf; stat(argv[1],&buf);
printf("the inode no is : %dn",buf.st_ino); if(S_ISDIR(buf.st_mode))
printf("it is a directory"); if(S_ISREG(buf.st_mode)) printf("it is regurlar filen");
printf("the no of links is %dn",buf.st_nlink); at=ctime(&buf.st_atime);
printf("the time of last access is %sn",at); mt=ctime(&buf.st_mtime);
printf("the modification time is :%sn",mt); ct=ctime(&buf.st_ctime);
printf("time of last change is : %sn",ct); if((buf.st_mode&S_IRUSR)==S_IRUSR)
printf("user has read permissionn"); if((buf.st_mode &S_IWUSR)==S_IWUSR)
printf("user has write permisssionn"); if((buf.st_mode &S_IXUSR)==S_IXUSR)
printf("user has execute permissionn"); if((buf.st_mode & S_IRGRP)==S_IRGRP)
printf("group has read permissionn"); if((buf.st_mode &S_IWGRP)==S_IWGRP)
printf("group has write permissionn"); if((buf.st_mode & S_IXGRP)==S_IXGRP)
printf("group has execute permissionn"); if((buf.st_mode &S_IROTH)==S_IROTH)
printf("others has read permissionn"); if((buf.st_mode &S_IWOTH)==S_IWOTH)

25. 25
printf("others has write permissionn"); if((buf.st_mode &S_IXOTH)==S_IXOTH)
printf("others has execute permisssionn");
}
OUTPUT:
$ gedit sample.c
$ gcc sample.c – o sample
$./ sample
the node number is :4
it is a directory
the number of links is 5
the time of last access is: 12.30 pm
the modification time: 12:40 pm
time of last change :12.40 pm
user has read permission
user has write permission
user has execute permissions
group has read
others has read permissions
others has write permissions
others has execute permissions
RESULT:
Hence the output is verified

26. 26
Ex. No.17 SUSPENDING AND RESUMING PROCESS
Date:
AIM:
To write the program for suspending and resuming process
PROCEDURE:
1. start
2. get the file name
3. call the process
4. enter suspend time of child process
5. enter parent sleep time
6. resume child process
7. terminate the child process
8. end the parent process
PROGRAM:
#include<stdio.h>
#include <ospace/linux.h>
int child _function( )
{
while (true)
{
printf(“child loop n”);
os_this_ process::sleep(1);
}
return 0;
}
int main()
{
os_linux_toolkit initialize;
os_process child(child function);
os_this_porocess::sleep(4);
print(“child.suspend()n”);
child.suspend();
printf(“parent sleep for 4 seconds n”);
os_this _process::sleep(4);
printf(“child.resume()n”);
child.resume();
os_this_process::sleep (4);
printf(“child.terminate()”);
child.terminate();
print(“parent finished”);
return 0;
}

27. 27
OUTPUT:
child loop
child loop
child loop
child loop
child loop
child.suspend()
parents sleep for 4 seconds
child.resume()
child loop
child loop
child loop
child loop
child.terminate()
child loop
parent finished
RESULT:
Hence the output is verified.