Bash Scripting-Adding Users

Q: - Create a bash script for adding a user and modifying access rights



Code:-

#!/bin/bash
echo "shell script to create new user and modify access rights"
while true
do
echo "Enter your choice"
echo "1.Change ownership 2.Change access rights 3.Add user 4.delete user  5.Add group 6. Delete Group 7.Change group of user 8.exit"
read choice
case $choice in 
1)
echo "current folder contents are"
ls -l
echo "enter the name of the file for which you wish to change ownership"
read accfile
if [ -f $accfile ]
then
echo "enter the name of the new owner"
read owner
chown -v $owner $accfile
echo "ownership successfully  changed"
else
echo "incorrect file name"
fi
;;
2)
echo "current folder contains the following files"
ls -l
echo "enter the name of the file for which access rights are to be changed"
read accfile
if [ -f $accfile ]
then
echo "enter octal number for user rights"
read octal
chmod -v $octal $accfile
echo "status of folder after operation is as follows"
ls -l
else
echo "invalid file name"
fi
;;
3)
echo "Enter the name of the user to add"
echo "current user are"
grep '/home' /etc/passwd | cut -d: -f1
read user
sudo useradd $user
echo "after adding new user the current users are"
grep '/home' /etc/passwd | cut -d: -f1
;;
4)
echo "current user are"
grep '/home' /etc/passwd | cut -d: -f1
echo "enter the name of the user to delete"
read user
sudo userdel $user
echo "after adding new user the current users are"
grep '/home' /etc/passwd | cut -d: -f1
;;
5)
echo "enter the name of the group to add"
read grpname
sudo groupadd $grpname
;;
6)
echo "enter the name of the group to delete"
read grpname
sudo groupdel $grpname
echo "the $grpname has been deleted" 
;;
7)
echo "enter the name of the user for which the secondary group is to be added"
read user
echo "enter the group to which it is to be added"
read groupname
usermod -a -G $groupname $user
echo "the group has been added, displaying the contents of the /etc/group"
cat /etc/group
;;
8)
echo "terminating script"
exit
;;
*)
echo "Invalid choice, enter choice again"
esac
done

Output

[root@localhost asgn3]# sh asgn3.sh

shell script to create new user and modify access rights

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

3

current user are

exam10

hduser

hduser1

student

Enter the name of the user to add

usernew

after adding new user the current users are

exam10

hduser

hduser1

student

usernew

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

1

current folder contents are

total 12

-rw-rw-r--. 1 student student 640 Aug 10 17:07 ab.cpp

-rw-rw-r--. 1 student student 1979 Aug 12 15:24 asgn3.sh

-rw-rw-r--. 1 student student 1979 Aug 12 15:24 asgn3.sh~

enter the name of the file for which you wish to change ownership

ab.cpp

enter the name of the new owner

usernew

changed ownership of `ab.cpp' from student to usernew

ownership successfully changed

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

2

current folder contains the following files

total 12

-rw-rw-r--. 1 usernew student 640 Aug 10 17:07 ab.cpp

-rw-rw-r--. 1 student student 1979 Aug 12 15:24 asgn3.sh

-rw-rw-r--. 1 student student 1979 Aug 12 15:24 asgn3.sh~

enter the name of the file for which access rights are to be changed

ab.cpp

enter octal number for user rights

777

mode of `ab.cpp' changed from 0664 (rw-rw-r--) to 0777 (rwxrwxrwx)

status of folder after operation is as follows

total 12

-rwxrwxrwx. 1 usernew student 640 Aug 10 17:07 ab.cpp

-rw-rw-r--. 1 student student 1979 Aug 12 15:24 asgn3.sh

-rw-rw-r--. 1 student student 1979 Aug 12 15:24 asgn3.sh~

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

5

enter the name of the group to add

groupnew

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

7

enter the name of the user for which the secondary group is to be added

usernew

enter the group to which it is to be added

groupnew

the group has been added, displaying the contents of the /etc/group

root:x:0:

bin:x:1:

daemon:x:2:

sys:x:3:

adm:x:4:

tty:x:5:

disk:x:6:

lp:x:7:

mem:x:8:

kmem:x:9:

wheel:x:10:

mail:x:12:

uucp:x:14:

man:x:15:

games:x:20:

gopher:x:30:

video:x:39:

dip:x:40:

ftp:x:50:

slocate:x:21:

tcpdump:x:72:

ccache:x:988:

pulse:x:987:

pulse-access:x:986:

gdm:x:42:

stapusr:x:156:

stapsys:x:157:

stapdev:x:158:

exam10:x:1012:

tomcat:x:91:

hadoop:x:1015:

student:x:1017:

mega:x:1018:

usernew:x:1019:

groupnew:x:1020:usernew

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

4

current user are

exam10

hduser

hduser1

student

usernew

enter the name of the user to delete

usernew

after adding new user the current users are

exam10

hduser

hduser1

student

Enter your choice

1.Change ownership 2.Change access rights 3.Add user 4.delete user 5.Add group 6. Delete Group 7.Change group of user 8.exit

6

enter the name of the group to delete

groupnew

the groupnew has been deleted

8

terminating script

[root@localhost asgn3]#