hi is there a peice of code that will pick a variable from a list out at randomYes...by picking out from array but random will only follow algorithm UNLESS you seed it. Random will always pick say 3,4,7,5,2 in that order if executed again and again after closing it unless you add a seed to influence the algorithms output in which the output is less likely to be guessed in the order at which it will spit out the outcome.

I have never seeded a random in a batch to give an example but am guessing that it follows the same rules as C, C++, or Perl with Time used.if you can download gawk for windows (see my sig)
Code: [Select]
C:\test>echo 1 2 3 4 5 10 8 5|gawk "BEGIN{srand()}{R=int(1+rand()*NF); print $(R)}"
8

C:\test>echo 1 2 3 4 5 10 8 5|gawk "BEGIN{srand()}{R=int(1+rand()*NF); print $(R)}"
4

C:\test>echo 1 2 3 4 5 10 8 5|gawk "BEGIN{srand()}{R=int(1+rand()*NF); print $(R)}"
4

C:\test>echo 1 2 3 4 5 10 8 5|gawk "BEGIN{srand()}{R=int(1+rand()*NF); print $(R)}"
3

C:\test>echo 1 2 3 4 5 10 8 5|gawk "BEGIN{srand()}{R=int(1+rand()*NF); print $(R)}"
5

C:\test>


No code is needed

Run CMD.EXE and type SET /?
At the end of several pages is a SMALL section on dynamic environmental variables that are sort of secret - if you do not know them you cannot see them.

%RANDOM% is one of them
ECHO %RANDOM% will display a (semi)random number that changes every time.

If you want a truly random sequence you will need to seed it.

Regards
Alan
Example for choosing a random # from 0 to 10:

Code: [Select]set /a return=%RANDOM%%10 Quote from: macdad- on June 16, 2009, 04:27:48 PM

Example for choosing a random # from 0 to 10:

Code: [Select]set /a return=%RANDOM%%10

Code: [Select]set /a return=%RANDOM%%10
that will only generate a rand number. imagine a list of numbers eg 10,20,30,40,50. you will need to get a random item out of this list, not by simply using the above code.

Well, most more advanced needs require more lines in a script.

echo off
:loop
set /a rnd=%random%%50
if %rnd% neq 50 if %rnd% neq 40 if %rnd% neq 30 if %rnd% neq 20 if %rnd% 10 goto loop
echo The random number is either 10, 20, 30, 40 or 50.
echo Your random number is %rnd%.
pause > nul

not really. if %RANDOM% doesn't hit a number in the list forever, are you going to wait forever??  :-Xuse the number of items on the list with %RANDOM% instead.

I personally have never used the %random%%10 style, but the 10, 20, 30, 40, 50 numbers was just an example.

For your example getting a random choice of a certain list, this would work. It would also work as a much quicker version than my previous code.

echo off
set /a rnd=%random%%5
set /a rnd*=10
echo %rnd%
pause>nul

would do the trick for your example.

not enough. try not to hard code those numbers.