Linux conditional judgment: Common practice to add users

1, practice writing a script to complete the following requirements:

1, add 3 users User1,user2,user3, but first to determine whether the user exists, does not exist and then add;

2, added after the completion, the display has added a total of several users, of course, can not be included because of pre-existing and not added;

3, finally shows how many users on the current system;

#!/bin/bash

#program

# Practice writing to add user command scripts

# History

# time:2016-10-19-9:00

Path=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bash

Export PATH

! ID user1 &>/dev/null && useradd user1 &>/dev/null && echo "user1" | passwd--stdin user1 &>/dev/null | | echo "User1 is exist."

! ID user2 &>/dev/null && useradd user2 &>/dev/null && echo "User2" | passwd--stdin user2 &>/dev/null | | echo "user2is exist."

! ID user3 &>/dev/null && useradd user3 &>/dev/null && echo "User3" | passwd--stdin user3 &>/dev/null | | echo "User3 is exist."

usernum= ' Wc-l/etc/passwd | Cut-d '-f1 '

echo "Users is $USERNUM."

2, practice writing a script to complete the following requirements:

given a user:

1, if its UID is 0, this is displayed as an administrator;

2, otherwise, it is displayed as a normal user;

#!/bin/bash

2 #program

3 # Practice Determining if a user is root

4 #history

5 #time 2016-10-19-9:38

6 Path=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bash

7 Export PATH

8 Username=user1

9 userid= ' Id-u $USERNAME '

[$USERID-eq 0] && echo "$USERNAME is Admin" | | echo "$USERNAME is command"

3, practice writing a script to complete the following tasks:

1, use a variable to save a user name;

2, delete the user in this variable, and delete their home directory;

3, display the "User Delete complete" class information;

#!/bin/bash

#program

# Practice to determine if a user exists and delete this user and home directory if it exists.

#history

#time 2016-10-19-9:53

Path=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bash

Export PATH

Username=user1

ID $USERNAME &>/dev/null && userdel-r $USERNAME && echo "$USERNAME is del" | | echo "$USERNAME is not exist."

This article is from the "Learn Linux history" blog, please be sure to keep this source http://woyaoxuelinux.blog.51cto.com/5663865/1863268

Linux conditional judgment: Common practice to add users