local_variables

# called in main
pry(main)> local_variables
=> [:__, :_, :_dir_, :_file_, :_ex_, :_pry_, :_out_, :_in_, :_erbout]

# called in method with no local vars
pry(main)> def a; local_variables; end
=> nil
pry(main)> a
=> []

#called in method with 1 local var
pry(main)> def a; b = 1; local_variables; end
=> nil
pry(main)> a
=> [:b]

# getting the values and the names (which i what is really needed)
pry(main)> def a; b = 1; local_variables.each {|name| p "#{name}: #{eval name.to_s}"}; end
=> nil
pry(main)> a
"b: 1"
=> [:b]