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
unix - Command: sudo su - - Super User 'sudo su -' has a child of 'su -', and 'su -' has a child of '-su'. As mentioned above, root user can do 'su -' without entering password, so doing 'su -' inside of a root shell, you will have two different root shell processes. ending the inner one will let you return back to the outer one. Linux Su Command Tutorial With Examples – POFTUT Dec 11, 2016 Sudo: List available commands | Benjamin Cane Aug 17, 2011 Understanding the difference between sudo and su command
Unlike the command su, users supply their personal password to sudo if necessary.After authentication, and if the configuration file permits the user access, the system invokes the requested command. sudo retains the user's invocation rights through a grace period (5 minutes) per pseudo terminal by default, allowing the user to execute several successive commands as the requested user without
May 04, 2019
This topic describes the functions, syntax, and parameters of all the MVS™ base control program (BCP) system commands. You can use these commands to control both the system itself and multiple console support (MCS), HMC multiple console support (HMCS) or SNA multiple console support (SMCS) consoles. Table 1 sums up the MVS BCP system commands and their functions.
Jun 18, 2019 SU Command in Linux: How to Use With Examples {2020 Tutorial}