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() system
call, /dev/urandom, /dev/random, or the libc pseudo-random functions,
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.
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
firstname.lastname@example.org. This page was obtained from the
project's upstream Git repository
2020-07-14. (At that time, the date of the most recent commit that
was found in the repository was 2020-07-14.) 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
util-linux December 2014 MCOOKIE(1)