ENV.rassoc(value) Class Public methods Returns an Array of the name and value of the environment variable with value or nil if the value cannot be found.

ENV.rehash Class Public methods Re-hashing the environment variables does nothing. It is provided for compatibility with Hash.

ENV.reject { |name, value| } â HashENV.reject â Enumerator Class Public methods Same as ENV#delete_if, but works on (and returns) a copy of the environment.

ENV.reject! { |name, value| } â ENV or nilENV.reject! â Enumerator Class Public methods Equivalent to ENV#delete_if but returns nil if no changes were made. Returns an Enumerator if no block was given.

ENV.replace(hash) â env Class Public methods Replaces the contents of the environment variables with the contents of hash.

ENV.select { |name, value| } â HashENV.select â Enumerator Class Public methods Returns a copy of the environment for entries where the block returns true. Returns an Enumerator if no block was given.

ENV.select! { |name, value| } â ENV or nilENV.select! â Enumerator Class Public methods Equivalent to ENV#keep_if but returns nil if no changes were made.

ENV.shift â Array or nil Class Public methods Removes an environment variable name-value pair from ENV and returns it as an Array. Returns nil if when the environment is empty.

ENV.size Class Public methods Returns the number of environment variables.

ENV.store(name, value) â value Class Public methods Sets the environment variable name to value. If the value given is nil the environment variable is deleted.