ufsdump

The ufsdump command is used by root to back up file systems. It does not cross file-system boundaries; however, it does support multivolume backups.

ufsrestore

The ufsrestore command is used to restore file systems that have been backed up using the ufsdump command.

umask

A user mask defines the default permissions for newly created files and directories. The user mask value is set with the umask command.

umount

The umount command removes a currently mounted file system, which may be specified as either a mount point or as the device on which the file system resides.

Unbundled Software

Unbundled software are software applications that are purchased separately from Sun or a third-party application vendor.

uncompress

The uncompress command uncompresses files compressed with the compress command.

User Account

A typical user account contains information a user needs to login and work on a system. It includes the user's name, password, home directory, and default login shell.

User Profile

The user profile is the $HOME/.profile file that is executed after the system profile when a user logs in to a system.

useradd

The useradd command is used to add new users and create the user's home directory.

uudecode

The uudecode command is used to decode an ASCII-encoded file into its binary representation. It reads an encoded file, strips off any leading and trailing lines added by mailer programs, and re-creates the original binary data with the filename, mode, and owner specified in the header.

uuencode

uuencode command is used to convert a binary file into an ASCII-encoded representation that can be sent using email. The encoded file is an ordinary ASCII text file.