Man1 - mcookie.1
Table of Contents
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NAME
mcookie - generate magic cookies for xauth
SYNOPSIS
mcookie [options]
DESCRIPTION
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-random
functions/
, in this preference order. See also the option =–file*=.=
OPTIONS
-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.=
-v*=, =–verbose*
Inform where randomness originated, with amount of entropy read from each source.
-V*=, =–version*
Display version information and exit.
-h*=, =–help*
Display help text and exit.
FILES
/dev/urandom
/dev/random
BUGS
It is assumed that none of the randomness sources will block.
SEE ALSO
*md5sum*=(1),= *X*=(7),= *xauth*=(1),= *rand*=(3)=
REPORTING BUGS
For bug reports, use the issue tracker at https://github.com/karelzak/util-linux/issues.
AVAILABILITY
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/.