how can disable a users access temporarily

Hi @newbie,

I hope you want to disable user account on server for login. You have two option to do it. First option would be to lock account using passwd.

sudo passwd -l sammy

Executing this command will lock account. When you try to SSH this will happen:

➜  ~ ssh sammy@ip
sammy@ip's password: 
Permission denied, please try again.

When you try su - sammy

➜  ~ su - sammy
Password: 
su: Authentication failure

When you need again your account you can unlock with:

sudo passwd -u sammy

Second option is to change login shell from /bin/bash to /bin/nologin Open /etc/passwd with any text editor:

sudo nano /etc/passwd

Find out line that starts with username which you want to disable, e.g.:

sammy:x:1001:1001:,,,:/home/sammy:/bin/bash

Note the highlighted /bin/bash. Change it to /bin/nologin:

sammy:x:1001:1001:,,,:/home/sammy:/bin/nologin

When you try to SSH you will get:

➜  ~ ssh sammy@ip
sammy@ip's password: 
Permission denied, please try again.

When you try to su - sammy:

➜  ~ su - sammy
Password: 
Cannot execute /bin/nologin: No such file or directory

When you want to enable it again, just change /bin/nologin to /bin/bash` :)