2011年10月22日 · su lets you switch user so that you're actually logged in as root. sudo -s runs a shell with root privileges. sudo -i also acquires the root user's environment. To see the difference between su and sudo -s, do cd ~ and then pwd after each of them. In the first case, you'll be in root's home directory, because you're root.

su - switches to the superuser and sets up the environment so that it looks like they logged in directly. su root switches to the user named root and doesn't simulate directly logging in. If the superuser is named root, then su and su root are equivalent (and don't simulate directly logging in), as are su - and su - root (which do).

2011年2月7日 · su - username sets up the shell environment as if it were a clean login as the specified user, it access and use specified users environment variables, su username just starts a shell with current environment settings for the specified user. If username is not specified with su and su -, the root account is implied as default.

su - means environment variables will be reset to root and su means environment variables as old user. for example: root's home directory if you use su - or old user home directory if you use su . sudo ( s uper u ser do ) is a command-line utility that allows users to run programs with the security privileges of another user, by default is ...

2018年8月22日 · Secondly: sudo -i and su - do the same thing (su - is equivalent to su --login), using different authorization mechanism: su verifies the password for the root account, while sudo verifies the password for your current user account and also verifies that your current user account is allowed to run administrative operations according to the /etc/sudoers policy.

If you write a password in a command like su <username> -p <password>, it would be stored in plain text in your bash history. This is certainly a huge security issue. If you need to run commands with su (or sudo) in an automated way, write a shellscript containig the commands without su or sudo and run su <username> script.sh

su And you will be prompted for the root password you've set. That's it! Share. Improve this answer ...

su asks for the password of the account you're trying to login. It's usage (simplified): su username When omitting username, the username default to root. Since the root password is disabled by default on Ubuntu, no password will be valid. The preferred way to run root commands is not through a su shell, but with sudo as in: sudo mount /dev ...

While you can create a password for the root account allowing you to log in as root with su, there are some distinct benefits to using sudo. Using sudo. Sudo is an alternative to giving people a root password in order to perform superuser duties. In a default Ubuntu install the person who installed the OS is given "sudo" permission by default.

I will create a question from it but sudo su - and sudo su -l differs. On an account where I ssh into with a key only, and I have sudo rights to change to a specific other user, sudo su - changes the user without problems but sudo su -l or sudo su --login will ask for a sudo password, which I don't have (although by examining sudo -l I could execute /bin/su with NOPASSWD)