Random Unique Serial Number Generator...

[Mel]

i need to create random unique serial numbers, say 10 chars + digits
combined

can anyone help ?

[Georgios Petasis]

set char_set {0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K a b c d e f g . . .}
set len [llength $char_set]
set serial {}
for {set i 0} {$i < 10} {incr i} {
set index [expr {int(rand()*$len)}]
append serial [lindex $char_set $index]
}
puts $serial

George

"Mel" <m...@redolive.com> wrote in message
news:rEG8b.5$B65....@news.uswest.net...

[Mark Bessey]

"Mel" <m...@redolive.com> wrote in message
news:rEG8b.5$B65....@news.uswest.net...

> i need to create random unique serial numbers, say 10 chars + digits
> combined
>
> can anyone help ?

You do realize that these two requirements are incompatible, right? Random
numbers won't necessarily be unique. You'll need to keep a list of all the
serial numbers you've used so far, then check each (pseudo-)random new
serial number against the list.

I'm not sure why you'd want a random number for a serial number, anyway.
Most serial numbers used in the real world actually have useful information
coded into themm - like the date of manufacture for hardware. This comes in
handy when you need to do a recall later ;-)

-Mark

[Wojciech Kocjan]

Mel wrote:

> i need to create random unique serial numbers, say 10 chars + digits
> combined

Basically, I use the following:

format %08x%08x%s [clock seconds] [clock clicks] [md5::md5 $hash]

hash is some unique string identifying a machine - for example in a
client connecting to a server, I do hash from some random string and all
the usernames/hostnames.

It is not random, but unique (although it is 48 bytes - though you could
use base64 instead of hex and get 32 bytes).

--
WK