Add a user and set a password in a shell script

Sometimes in the initialization shell script you want to be able to create a user and specify a password, you can use the Useradd command to achieve this effect:

useradd -m -p encryptedPassword username

Parameter description:

• -M: Automatically set up the user's log in directory;
• -P Encryptedpassword: The return value of the encrypted password, method crypt ().
• Username user name to add

How to generate an encrypted password:

Use the Perl crypt () method to encrypt plaintext passwords, as shown in the following example:

$ perl -e ‘print crypt("password", "salt"),"\n"‘

The output is as follows:

sa3tHJ3/KuYvI

For the Useradd command need to use the encryption password, using ' password ' as salt, the specific syntax is as follows:

password="[email protected]"pass=$(perl‘print crypt($ARGV[0], "password")‘$password)echo$passpaU5t8Al/qf6M

The sample shell script is used to create the user:

adduser.sh

#!/bin/bash# Script to add a user to Linux systemif [ $(id -u) -eq 0 ]; then    read -p "Enter username : " username    read -s -p "Enter password : " password    egrep "^$username" /etc/passwd >/dev/null    if [ $? -eq 0 ]; then        echo "$username exists!"        exit 1    else        pass=$(perl -e ‘print crypt($ARGV[0], "password")‘ $password)        useradd -m -p $pass $username        [ $? -eq 0 ] && echo "User has been added to system!" || echo "Failed to add a user!"    fielse    echo "Only root may add a user to the system"    exit 2fi

Execute the script under the root user:

# ./adduser.shEnter username : rojaEnter password : HIDDENUser has been added to system!

Add the user's shell to your own use:

...#如果是生产环境,为了防止明文密码泄露,可以对shell脚本进行加密password="[email protected]"username="py"pass=$(perl -e ‘print crypt($ARGV[0], "password")‘ $password)useradd -m -p $pass $username...

Reference Links:

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Add a user and set a password in a shell script