Re: how to generate random negative numbers

[Scott Gifford <sgifford@suspectclass.com>]

Soren Orel <soren.orel@gmail.com> writes:

> user@debian:~$ $[ ($RANDOM % 30 ) -30 ]
> bash: -26: command not found

[...]

> it still doesn't work, and it gives only negative numbers when using e.g.:
> 30....-30

First, it's giving an error because it's generating a random number,
then trying to run a program with that name.  If you try:

    echo $[ ($RANDOM % 30 ) -30 ]

it will print the number instead of running it.

Second, "$RANDOM % 30" will give a random number between 0 and 29, so
when you subtract 30 it will always be negative.  For -30..30, you
want to have it pick a number between 0 and 60, then subtract 30:

    echo $[ ($RANDOM % 61 ) -30 ]

Hope this helps!

----Scott.