[ubuntux]

چطوری می تونم ruby رو تو ubuntu نصب کنم تو سایت خودش نوشته ولی میزنم کار نمی کنه :

~$ sudo apt-get install ruby1.8 irb1.8 rdoc1.8
Reading package lists... Done
Building dependency tree... Done
Package ruby1.8 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package ruby1.8 has no installation candidate