OS Manuals

/usr/bin/mcookie

Generate random numbers for xauth from util-linux

From mcookie 2.42.4-r2 (os), captured 2026-11-05 by running mcookie --help (exit 0). permalink

Usage:
 mcookie [options]

Generate magic cookies for xauth.

Options:
 -f, --file <file>     use file as a cookie seed
 -m, --max-size <num>  limit how much is read from seed files
 -v, --verbose         explain what is being done

 -h, --help            display this help
 -V, --version         display version

Arguments:
 Values for <num> may be followed by a suffix: KiB, MiB,
 GiB, TiB, PiB, EiB, ZiB, or YiB (where the "iB" is optional).

For more details see mcookie(1).
Options (5)
OptionDescriptionSource
-f, --file fileUse this file as an additional source of randomness (for example /dev/urandom).help + man
-m, --max-size numRead from file only this number of bytes.help + man
-v, --verboseInform where randomness originated, with amount of entropy read from each source.help + man
-h, --helpDisplay help text and exit.help + man
-V, --versionDisplay version and exit.help + man

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.