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  /dev/urandom,  /dev/random, or the libc pseudo-random
       functions, in this preference order.

OPTIONS

       -f, --file file
              Use this file as an additional source of randomness.  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.

BUGS

       It is assumed that none of the randomness sources will block.

FILES

       /dev/urandom
       /dev/random

SEE ALSO

       X(1), xauth(1), md5sum(1), rand(3)

AVAILABILITY

       The  mcookie  command is part of the util-linux package and is available from Linux Kernel
       Archive ⟨ftp://ftp.kernel.org/pub/linux/utils/util-linux/⟩.