Ruby

Ruby is the new kid on the block as far as cgi languages go, but it's making a big splash, primarily because of a package called "Ruby on Rails." This package is designed to get your web applications up and running quickly with a minimum of effort. Since I've never used Ruby on Rails, I can't say how well it works.

This program compiles and runs under the WIN32 version of Ruby. It must be run from the command line, it will not work as a cgi script.

Because some servers will accept Ruby files in any directory, not just cgi-bin, the .rb suffix on the source file has been disabled by adding .txt to the end.


#This line is used to invoke the interpreter for cgi scripts


# //////////////////////////////////////////////////////////


# // Name: Peter M. Maurer


# // Program: Sieve of Eratosthenes


# // Due: Never


# // Language: Ruby


# //////////////////////////////////////////////////////////



# define the sieve data structure


i = 0


Candidates = [1]


i = 0


while i<1000


# everything is potentially prime until proven otherwise


Candidates.push(1)


i = i+1


end


# Neither 1 nor 0 is prime, so flag them off


Candidates[0] = 0


Candidates[1] = 0


# start the sieve with the integer 0


i = 0


while i<1000


# advance to the next un-crossed out number.


# this number must be a prime


while (i<1000 && Candidates[i] == 0)


i = i+1


end


# insure against running off the end of the data structure


if i<1000


# cross out all multiples of the prime, starting with 2*p.


j = 2


while (j*i) < 1000


Candidates[j*i] = 0


j = j+1


end


# advance to the next candidate


i = i+1


end


end


# all uncrossed-out numbers are prime (and only those numbers)


# print all primes


i=0


while i<1000


if Candidates[i] != 0


print i," is prime\n";


end


i = i+1


end

Click Here for the actual code.