fakeroot

Start the 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

-v
    Enable verbose mode.

-i
    Load initial fakeroot state from .

-s
    Save final fakeroot state to .

-l
    Use for intercepting system calls.

-u
    Run as user instead of the invoking user.

-g
    Run as group instead of the invoking group.

-h
    Display help message and exit.

fakeroot allows a user to run programs as if they were the root user, without actually requiring root privileges. It achieves this by intercepting file system access syscalls and manipulating the reported user and group IDs. This enables users to create archives, build packages, or perform other tasks that normally require root access, within a sandboxed environment.

It's important to understand that fakeroot *does not* grant true root privileges. Any operations that truly require root access, such as modifying system files outside the user's home directory or installing software system-wide, will still be blocked by the kernel's security mechanisms. fakeroot only fools the program running under it. It's a useful tool for development and testing where mimicking root operations is necessary.

fakeroot does not provide true root access. It only simulates the behavior of a program running as root. Kernel-level restrictions still apply. It is not a security bypass, and shouldn't be used to access files/folders outside of the user's permissions. Using external binaries can bypass the fakeroot environment.

fakeroot uses environment variables like FAKEROOTKEY to manage its state and communication between the fakeroot program and the intercepted program. These variables are set and managed internally by fakeroot and shouldn't be directly manipulated by the user.

fakeroot maintains a database of file ownership and permissions. The -i and -s options allow you to load and save this state, enabling you to continue a fakeroot session later. However, modifying files outside the fakeroot environment while a session is ongoing can lead to inconsistencies and unexpected behavior.

fakeroot was initially written to allow users to create Debian packages without needing root privileges. It has since become a widely used tool for various tasks where simulating root access is beneficial. The tool has been continuously maintained and improved over the years.

chroot(8), sudo(8)