Forum: Ruby Searching a hash by value

Hi
I am looking at google for this solution
i got few commands to do that... but i cant figured it out ,

example  my code

result = JSON.parse(response.body)

                result.each do |key,value|

                        #if k.has_value?'CHECK_NRPE: Socket timeout
after 10 seconds'
                                puts
"-----------------------------------------------"
                                puts    key["host_display_name"]
#reference properties like this
                                puts    key["plugin_output"]  # this is
the result in object form
                                puts    key["display_name"]
                                puts    key["last_time_critical"]
                                puts
"------------------------------------------------"
                        #end
                end


Basically the output is like :

myserver.home.lan
CHECK_NRPE: Socket timeout after 10 seconds.
Memory Load
1355046656

What i am after is

if key["plugin_output"]  == "CHECK_NRPE: Socket timeout after 10
seconds."
puts    key["host_display_name"] #reference properties like this
end

but that doe not work
also if i try

 if result.has_value?'CHECK MAINT: MAINTANANCE MODE ENABLED ON HOST'
stil it through the error

Can any one please give me some light on this
Thanks

Ferdous ara wrote in post #1088371:
> Hi
> I am looking at google for this solution
> i got few commands to do that... but i cant figured it out ,
>
> example  my code
>
> result = JSON.parse(response.body)
>
>                 result.each do |key,value|
>
>                         #if k.has_value?'CHECK_NRPE: Socket timeout
> after 10 seconds'
>                                 puts
> "-----------------------------------------------"
>                                 puts    key["host_display_name"]
> #reference properties like this
>                                 puts    key["plugin_output"]  # this is
> the result in object form
>                                 puts    key["display_name"]
>                                 puts    key["last_time_critical"]
>                                 puts
> "------------------------------------------------"
>                         #end
>                 end
>
>
> Basically the output is like :
>
> myserver.home.lan
> CHECK_NRPE: Socket timeout after 10 seconds.
> Memory Load
> 1355046656
>
> What i am after is
>
> if key["plugin_output"]  == "CHECK_NRPE: Socket timeout after 10
> seconds."
> puts    key["host_display_name"] #reference properties like this
> end
>
> but that doe not work
> also if i try
>
>  if result.has_value?'CHECK MAINT: MAINTANANCE MODE ENABLED ON HOST'
> stil it through the error
>
> Can any one please give me some light on this
> Thanks

 Well, let see if I understand, meaby you are confused. Judging by your
code, the result variable points to a #Hash, so:

#result = {key => value, ..}

 So, if I'm in the right way then I realize that each key is also a
#Hash, because you say:

#key["host_display_name"]

 So the result variable appear to be something like this:

#result = {#Hash => value, ..}

 Meaby the values are the Hash and the keys are another object, like a
symbol. I didn't played with JSON, don't know how it works, but if my
aproach is right instead of do #key["host_display_name"] you have to do:

#value["host_display_name"]

 If the result variable is something like this:

#result = {:some_key => {"host_display_name" => #Object}, ..}

> #Hash, because you say:
>
> #key["host_display_name"]
>
>  So the result variable appear to be something like this:
>
> #result = {#Hash => value, ..}

yes  that right , a sample out put is like

       "notes" : "HP Raid Check",
      "host_notifications_enabled" : 1,
      "host_active_checks_enabled" : 1,
      "icon_image" : "",
      "check_interval" : 60,

So if i say  puts key["notes"]   : the value will be HP raid Check


but will this work : #value["host_display_name"] ??
I will try in a bit ..

On Sun, Dec 9, 2012 at 1:35 PM, Ferdous ara <lists@ruby-forum.com> 
wrote:

> but will this work : #value["host_display_name"] ??
> I will try in a bit ..

No.  For lookup by value you can use Hash#rassoc:

irb(main):003:0> h={"foo" => "bar"}
=> {"foo"=>"bar"}
irb(main):004:0> h.rassoc "bar"
=> ["foo", "bar"]
irb(main):005:0> key, val = h.rassoc "bar"
=> ["foo", "bar"]
irb(main):006:0> key
=> "foo"

Be warned though that this may be inefficient.  You probably want a
second Hash keyed by value.

Kind regards

robert

may be i need to design my logic in a different way
let me explain

basically in that hash table (out put of JSON)

as key => value



i got like this
[
{
"notes_expanded" : "check_maintanance_mode",
      "host_comments" : [],
      "host_icon_image_expanded" : "",
      "checks_enabled" : 1,
      "max_check_attempts" : 3,
       "host" : service2.home.lan,

}
{
"notes_expanded" : "check_memory ",
      "host_comments" : [],
      "host_icon_image_expanded" : "",
      "checks_enabled" : 1,
      "max_check_attempts" : 3,
       "host" : service.home.lan,

}
{
"notes_expanded" : "check_maintanance_mode",
      "host_comments" : [],
      "host_icon_image_expanded" : "",
      "checks_enabled" : 1,
      "max_check_attempts" : 3,
      "host" : service.home.lan,

}
]

So Basically i want to get all the host which
notes_expanded  = check_maintanance_mode
so i  should get only 2

Does it make sense ??

On Sun, Dec 9, 2012 at 2:21 PM, Ferdous ara <lists@ruby-forum.com> 
wrote:
> [
> "notes_expanded" : "check_memory ",
>       "host_icon_image_expanded" : "",
>
> Does it make sense ??

Yes, but it's something completely different than selecting from a
Hash based on values.  You rather want something like

items = stuff.select {|h| h["notes_expanded"] == 
"check_maintanance_mode"}

Kind regards

robert

data = [
  {
    "notes_expanded" => "check_maintenance_mode",
    "host_comments" => [],
    "host_icon_image_expanded" => "",
    "checks_enabled" => 1,
    "max_check_attempts" => 3,
    "host" => "service2.home.lan",

  },
  {
    "notes_expanded" => "check_memory ",
    "host_comments" => [],
    "host_icon_image_expanded" => "",
    "checks_enabled" => 1,
    "max_check_attempts" => 3,
    "host" => "service.NOT_THIS_ONE.home.lan",
  },
  {
    "notes_expanded" => "check_maintenance_mode",
    "host_comments" => [],
    "host_icon_image_expanded" => "",
    "checks_enabled" => 1,
    "max_check_attempts" => 3,
    "host" => "service.home.lan",
  },
]


results = []

data.each do |hash|
  if hash["notes_expanded"] == "check_maintenance_mode"
    results << hash["host"]
  end
end

p results

--output:--
["service2.home.lan", "service.home.lan"]