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.

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.

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 ...

2016年10月24日 · From su's man page: For backward compatibility, su defaults to not change the current directory and to only set the environment variables HOME and SHELL (plus USER and LOGNAME if the target user is not root). It is recommended to always use the --login option (instead of its shortcut -) to avoid side effects caused by mixing environments.

2013年1月20日 · Alternatively, you can disable the group membership check for su in pam by editing /etc/pam.d/su and commenting out this line: auth required pam_wheel.so use_uid It requires users to be in the wheel group to be able to switch user. User switching as non-root works again when this pam module is disabled for su.

2013年10月7日 · 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

$ sudo su -c whoami nobody [sudo] password for oli: nobody When your command takes arguments you need to quote it. If you don't, strange things will occur. Here I am —as root— trying to create a directory in /home/oli (as oli) without quoting the full command: # su -c mkdir /home/oli/java oli No passwd entry for user '/home/oli/java'

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