My jprofile has included a script for several years useful in Linux and
OS X - the name (pgseed) stands for PrettyGoodSeed
pgseed
3 : '9!:1 {. _2 (3!:4) (4?4){ host ''dd if=/dev/random bs=4 count=1'''
host
[: 2!:0 '(' , ' || true)' ,~ ]
pgseed ''
1+0 records in
1+0 records out
4 bytes transferred in 0.000034 secs (117323 bytes/sec)
This "noise of standard output" doesn't bother my use of the above since
I use it primarily in CGI scripts.
The host verb is a nice cover (thanks to Martin Neitzel) for 2!:0
Unix utility dd is a very low level way to read stream files. The stuff
operating on the result of the call via host is a bit over the top, but
I do believe this provides a pretty good seed, and doesn't drink much
from the entropy pool.
On 2013/03/13 09:17 , bill lam wrote:
You may remove the newline at the end and convert the string
into a number, eg
". LF-.~ 2!:0 'cat /dev/urandom|od -N4 -An -i'
1281601434
long may be use in J64
0". LF-.~ 2!:0 'cat /dev/urandom|od -N8 -An -l'
8774956622310178816
Ср, 13 мар 2013, Brian Schott писал(а):
Bill,
Your approach produced the following results on my Mac OS X. Notice
the two blank lines and the negative number result.
2!:0 'cat /dev/urandom|od -N4 -An -i'
818045955
2!:0 'cat /dev/urandom|od -N4 -An -i'
-1293144445
--
(B=)
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