fakeroot

Start default shell as fakeroot

$ fakeroot

$ fakeroot -- [command] [command_arguments]

$ fakeroot -s [path/to/file] -- [command] [command_arguments]

$ fakeroot -i [path/to/file] -- [command] [command_arguments]

$ fakeroot [-u|--unknown-is-real] -- [command] [command_arguments]

$ fakeroot [-h|--help]

fakeroot [options] [command]

fakeroot runs commands in an environment that fakes root privileges for file manipulation. It intercepts system calls to make files appear owned by root without actual root access.
Commonly used for building packages that need to create root-owned files.

fakeroot runs commands in an environment that fakes root privileges for file manipulation. It intercepts system calls to make files appear owned by root without actual root access.
The tool uses LD_PRELOAD to intercept library calls and maintain a database of fake ownership and permission information. When a program creates a file, fakeroot records it as owned by root (uid 0, gid 0) while the actual file on disk retains the user's ownership.
This is commonly used for building packages (particularly Debian .deb packages) that need to create root-owned files. The saved environment (-s/-i) allows preserving fake ownership across multiple commands and sessions.

-s file

Save fakeroot environment on exit

Load fakeroot environment

Keep real ownership of unknown files

Display help

Does not provide real root privileges. Only fakes ownership information. Used extensively in package building systems like dpkg-buildpackage.

sudo(8), dpkg-buildpackage(1)