| .\" mcookie.1 -- |
| .\" Public Domain 1995 Rickard E. Faith (faith@cs.unc.edu) |
| .TH MCOOKIE 1 "December 2014" "util-linux" "User Commands" |
| .SH NAME |
| mcookie \- generate magic cookies for xauth |
| .SH SYNOPSIS |
| .B mcookie |
| [options] |
| .SH DESCRIPTION |
| .B mcookie |
| generates a 128-bit random hexadecimal number for use with the X authority |
| system. Typical usage: |
| .sp |
| .RS |
| .B xauth add :0 . `mcookie` |
| .RE |
| .PP |
| The "random" number generated is actually the MD5 message |
| digest of random information coming from one of the sources |
| .IR /dev/urandom , |
| .IR /dev/random , |
| or the |
| .IR "libc pseudo-random functions" , |
| in this preference order. |
| .SH OPTIONS |
| .TP |
| .BR \-f , " \-\-file " \fIfile |
| Use this \fIfile\fR as an additional source of randomness. |
| When \fIfile\fR is '-', characters are read from standard input. |
| .TP |
| .BR \-m , " \-\-max\-size " \fInumber |
| Read from \fIfile\fR only this \fInumber\fR of bytes. |
| This option is meant to be used when reading additional |
| randomness from a file or device. |
| .IP |
| The |
| .I 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. |
| .TP |
| .BR \-v , " \-\-verbose" |
| Inform where randomness originated, with amount of entropy read from each |
| source. |
| .TP |
| .BR \-V , " \-\-version" |
| Display version information and exit. |
| .TP |
| .BR \-h , " \-\-help" |
| Display help text and exit. |
| .SH BUGS |
| It is assumed that none of the randomness sources will block. |
| .SH FILES |
| .I /dev/urandom |
| .br |
| .I /dev/random |
| .SH "SEE ALSO" |
| .BR X (1), |
| .BR xauth (1), |
| .BR md5sum (1), |
| .BR rand (3) |
| .SH AVAILABILITY |
| The mcookie command is part of the util-linux package and is available from |
| .UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/ |
| Linux Kernel Archive |
| .UE . |