fakeroot-pseudo man page

fakeroot — run a command in an environment faking root privileges for file manipulation

Synopsis

fakeroot [-i|-s local-state-dir] [-h|--help ] [-v|--version ] [--] [command]

Description

fakeroot runs a command in an environment wherein it appears to have root privileges for file manipulation. This is useful for allowing users to create file system images, archives and packages (tar, ar, .deb etc.) with files in them with root permissions/ownership. Without fakeroot one would need to have root privileges to create the constituent files of the archives with the correct permissions and ownership, and then pack them up, or one would have to construct the archives directly, without using the archiver. This version of fakeroot uses pseudo(1) to replace the file manipulation library functions (chmod(2), stat(2) etc.) by ones that simulate the effect the real library functions would have had, had the user really been root.

Options

-l arg, --lib arg
Does nothing, accepted for compatibility only.
--faked arg
Does nothing, accepted for compatibility only.
[--] command
Any command you want to be ran as fakeroot. Use ‘--’ if in the command you have other options that may confuse fakeroot's option parsing.
-s local-state-dir
Keep the pseudo state directory on exit. This directory holds the pseudo database files and log files. See the pseudo documentation on the details on how this directory can be reused.
-i local-state-dir
Load a pseudo environment previously saved using -s from the specified directory. Note that this does not implicitly save the direcotry, use -s instead for that behaviour. Using the same file for both -i and -s in a single fakeroot invocation is safe.
-u,
--unknown-is-real Does nothing, accepted for compatibility only.
-b fd
Does nothing, accepted for compatibility only.
-h
Display help.
-v
Display version.

Examples

Here is an example session with fakeroot. Notice that inside the fake root environment file manipulation that requires root privileges succeeds, but is not really happening.

$  whoami
joost
$ fakeroot /bin/bash
#  whoami
root
# mknod hda3 b 3 1
# ls -ld hda3
brw-r--r--   1 root     root       3,   1 Jul  2 22:58 hda3
# chown joost:root hda3
# ls -ld hda3
brw-r--r--   1 joost    root       3,   1 Jul  2 22:58 hda3
# ls -ld /
drwxr-xr-x  20 root     root         1024 Jun 17 21:50 /
# chown joost:users /
# chmod a+w /
# ls -ld /
drwxrwxrwx  20 joost    users        1024 Jun 17 21:50 /
# exit
$ ls -ld /
drwxr-xr-x  20 root     root         1024 Jun 17 21:50 //
$ ls -ld hda3
-rw-r--r--   1 joost    users           0 Jul  2 22:58 hda3

Only the effects that user joost could do anyway happen for real.

fakeroot was specifically written to enable users to create Debian GNU/Linux packages (in the deb(5) format) without giving them root privileges. This can be done by commands like dpkg-buildpackage -rfakeroot or debuild -rfakeroot (actually, -rfakeroot is default in debuild nowadays, so you don't need that argument).

Security Aspects

fakeroot is a regular, non-setuid program. It does not enhance a user's privileges, or decrease the system's security.

Bugs

See pseudo(1) for the details on the bugs of the underlying fakeroot implementation.

Copying

fakeroot wrapper for pseudo is distributed under the GNU General Public License version 3.0 or later. pseudo itself is distributed under the GNU Lesser General Public License version 2.1 or later.

Authors

The original fakeroot manual page has mostly been written by J.H.M. Dassen <jdassen@debian.org> with rather a lot modifications and additions by joost and Clint. It was later modified by Andrew Shadura for this fakeroot wrapper for pseudo.

See Also

pseudo(1), fakeroot(1), dpkg-buildpackage(1), debuild(1)

Info

22 November 2015 Debian Project Debian manual