scope - Ruby set local variable inside a block -

i have variable set default value on, , perform procedure on. thing is, don't have access variable inside block block has it's own variable scope , no access outside. here snippet:

value = "" cmd_errors = array.new  # call command line status = popen4.popen4(cmd) |stdout, stderr|   output = stdout.read   error  = stderr.read   if (!output.empty?)     value = json.parse(output)      #this creates block scoped variable called 'value' , local variable still empty   else     cmd_errors << error   end end 

is possible allow block write local variable? perhaps using references?

in program, external value variable is being modified block. usual assign nil such external variables, have work fine.

try modifying value else inside block, this, , see variable being changed. guess output.empty? coming true.

value = nil cmd_errors = array.new  status = popen4.popen4(cmd) |stdout, stderr|   output = stdout.read   error  = stderr.read   value = 'within block'   if (!output.empty?)     value = json.parse(output)   else     cmd_errors << error   end end  p value