.PP
The "random" number generated is actually the MD5 message
digest of random information coming from one of the sources
+.IR "getrandom() "
+system call,
.IR /dev/urandom ,
.IR /dev/random ,
or the
.IR "libc pseudo-random functions" ,
-in this preference order.
+in this preference order. See also the option \fB\-\-file\fR.
.SH OPTIONS
.TP
.BR \-f , " \-\-file " \fIfile
-Use this \fIfile\fR as an additional source of randomness.
+Use this \fIfile\fR as an additional source of randomness (for example /dev/urandom).
When \fIfile\fR is '-', characters are read from standard input.
.TP
.BR \-m , " \-\-max\-size " \fInumber