ruby language syntax(how platform_info variable is used

 class EncodeDemoTest < Test                      #inheritance in ruby  
      def setup(platform_info, logdir)
        @telnet_ip                  = platform_info["telnet_ip"]
        @telnet_login               = platform_info["telnet_login"]
        @telnet_password            = nil
        @filesys_path               = platform_info["filesys_path"]
        @host_files_path            = platform_info["host_files_path"]
        @host_machine_ip            = platform_info["host_machine_ip"]
        @linuxserver_ip             = platform_info["linuxserver_ip"]
        @target_prompt              = platform_info["target_prompt"]
        @demo_execuable_path        = platform_info["demo_execuable_path"]
        @mts4ea_machine_ip          = platform_info["mts4ea_machine_ip"]
        @mts4ea_files_path          = platform_info["mts4ea_files_path"]
        @ffmpeg_machine_ip          = platform_info["ffmpeg_machine_ip"]
        @ffmpeg_service_machine_ip  = platf开发者_JS百科orm_info["ffmpeg_service_machine_ip"]          
        @ffmpeg_files_path          = platform_info["ffmpeg_files_path"]
        @ffmpeg_login               = platform_info["ffmpeg_login"]
        @ffmpeg_password            = platform_info["ffmpeg_password"]
        @ffmpeg_prompt              = platform_info["ffmpeg_prompt"]
        @platform_info              = platform_info

could anyone tell me how argument passed in setup method .means what does that syntax means platform_info["telnet_ip"]

It looks like platform_info is intended to be a Hash.

setup would be called with something like setup({'telnet_ip' => 'value'}, 'logdir_value') and platform_info["telnet_ip"] would then return the value from platform_info for the key "telnet_ip".

Update

Given the code:

@board = Target::TelnetClient.new "192.168.247.68", "root", 
  @telnet_password, logdir + "/log.txt"
app = Target::EncodeDemoApp.new() app.setup(@board, @demo_execuable_path)

it looks like @board is not a Hash but is a Target::TelnetClient which must have a [] method that makes it behave like a Hash.

If you want to find out what class something is you can use the class method e.g. you can put in your program:

puts "@board is a #{@board.class}"
puts "@demo_executable_path is a #{@demo_executable_path.class}"

For @board, to see what values it contains (telnet_ip, telnet_login etc) you could try:

puts @board.keys.inspect

Finally, to see the methods that an object provides you can use public_methods e.g.

puts @board.public_methods.inspect