Synopsis openssl rand [-out file] [-rand file(s)] [-base64] num
DESCRIPTIONThe rand command outputs num pseudo-random bytes after seeding the random number
generator once. As in other openssl command line tools, PRNG seeding
uses the file $HOME/ .rnd or .rnd in addition to the files given in the
-rand option. A new $HOME/.rnd or .rnd file will be written back if enough
seeding was obtained from these sources. OPTIONS
-out file Write to file instead of standard output.
-rand file(s) Use specified file or files or EGD socket (see RAND_egd(3) )
for seeding the random number generator. Multiple files can be specified
separated by a OS-dependent character. The separator is ; for MS-Windows, ,
for OpenVMS, and :for all others.
HP Open Source Security for OpenVMS Volume 2:... 
OpenSSL Command Line Interface (CLI) Reference
