mcookie generates a 128-bit random hexadecimal number for use
with the X authority system. Typical usage:
xauth add :0 . mcookie
The "random" number generated is actually the MD5 message digest
of random information coming from one of the sources getrandom(2)
system call, /dev/urandom, /dev/random, or the libc pseudo-randomfunctions, in this preference order. See also the option --file.
-f, --file file
Use this file as an additional source of randomness (for
example /dev/urandom). When file is '-', characters are read
from standard input.
-m, --max-size number
Read from file only this number of bytes. This option is
meant to be used when reading additional randomness from a
file or device.
The number argument may be followed by the multiplicative
suffixes KiB=1024, MiB=1024*1024, and so on for GiB, TiB,
PiB, EiB, ZiB and YiB (the "iB" is optional, e.g., "K" has
the same meaning as "KiB") or the suffixes KB=1000,
MB=1000*1000, and so on for GB, TB, PB, EB, ZB and YB.
Inform where randomness originated, with amount of entropy
read from each source.
Display version information and exit.
Display help text and exit.
The mcookie command is part of the util-linux package which can
be downloaded from Linux Kernel Archive
<https://www.kernel.org/pub/linux/utils/util-linux/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
email@example.com. This page was obtained from the
project's upstream Git repository
2021-08-27. (At that time, the date of the most recent commit
that was found in the repository was 2021-08-24.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to firstname.lastname@example.org
util-linux 2.37.85-637cc 2021-04-02 MCOOKIE(1)