Module: Findme

Defined in:
lib/findme.rb,
lib/findme/version.rb

Constant Summary collapse

AVAHI_SERVICE_DIR = 
"/etc/avahi/services/"
AVAHI_BROWSE = 
"/usr/bin/avahi-browse"
VERSION = 
"0.0.8"

Class Method Summary collapse

Class Method Details

._get_startup_time(str) ⇒ Object 



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# File 'lib/findme.rb', line 33

def self._get_startup_time str
  begin
    pairs = str.strip.split(" ")
    pairs.each do |p|
      kv=p.strip.split("=")
      if kv[0] == "\"findme_startup_time"
        return kv[0].to_i
      end
    end
  rescue Exception => e
    # do nothing or if you want to debug: puts e
  end
  nil
end

.cleanup ⇒ Object

clean up all the services this gem registered. should be called by user to clean up unused services.



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# File 'lib/findme.rb', line 15

def self.cleanup
  findme_services = []
  files_with_path = Dir.glob(AVAHI_SERVICE_DIR + "*.service")
  files_with_path.each do |fwp|
    File.open(fwp, 'r') do |infile|
      while (line = infile.gets)
        if line.strip == "<!-- findme generated -->"
          findme_services << fwp
        end
      end
    end
  end
  findme_services.each do |fs|
    puts "Removing #{fs}"
    File.delete fs
  end
end

.discover(custom_cmd = nil) ⇒ Object 



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# File 'lib/findme.rb', line 116

def self.discover custom_cmd=nil

  if custom_cmd.nil?
    res = `avahi-browse -arpt`
  else
    res = `#{custom_cmd}`
  end

  services = []
  lines = res.scan(/\S+/)
  lines.each do |line|
    if line[0] == "="
      elems=line.split(";")
      as = AvahiService.new
      as.eth      = elems[1]
      as.ipv4     = elems[2]
      as.hosttxt  = elems[3]
      as.service  = elems[4]
      as.hostname = elems[6]
      as.ip       = elems[7]
      as.port     = elems[8]
      as.txt      = elems[9]
      services << as
    end
  end
  services
end

.discover_only_earliest ⇒ Object 



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# File 'lib/findme.rb', line 48

def self.discover_only_earliest
  services = discover
  h = {}
  h_out={}

  #construct the hash, group the services of the same name
  services.each do |s|
    if h[s.service].nil?
      h[s.service]=[]
    else
      #existing hash, do nothing
    end
    h[s.service] << s
  end

  h.each do |k, v|
    if (_get_startup_time v[0].txt).nil?
      #cant find the earliest time, just return the first one.
    else
      v.sort! {|x,y| _get_startup_time(x.txt) <=> _get_startup_time(y.txt) }
    end
    h_out[k]=v.last #fix a bug here.
  end
  h_out
end

.discover_only_latest ⇒ Object 



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# File 'lib/findme.rb', line 74

def self.discover_only_latest
  services = discover
  h = {}
  h_out={}

  #construct the hash, group the services of the same name
  services.each do |s|
    if h[s.service].nil?
      h[s.service]=[]
    else
      #existing hash, do nothing
    end
    h[s.service] << s
  end

  h.each do |k, v|
    if (_get_startup_time v[0].txt).nil?
      #cant find the earliest time, just return the first one.
    else
      v.sort! {|x,y| _get_startup_time(x.txt) <=> _get_startup_time(y.txt) }
    end
    h_out[k]=v.first #latest registerd.
  end
  h_out
end

.discover_service(service, ip = nil) ⇒ Object 



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# File 'lib/findme.rb', line 100

def self.discover_service(service, ip=nil)
  services = discover

  result = services.detect {|x| x.service == "_#{service}._tcp" && x.ip == ip}
  return result if result #here we choose best match if previous is this ip
  #todo, using other factor to determine rank algorithm
  return services.detect {|x| x.service == "_#{service}._tcp"}[0]
end

.discover_services(service) ⇒ Object 



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# File 'lib/findme.rb', line 109

def self.discover_services(service)
  services = discover

  result = services.select {|x| x.service == "_#{service}._tcp" }
end

.mac ⇒ Object

find the mac address



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# File 'lib/findme.rb', line 180

def self.mac
  return @mac_address if defined? @mac_address
  re = %r<(?:hwaddr|:)\s+((?:[0-9a-f]{1,2}[-:]){5}[0-9a-f]{1,2})\s*$>i
  lines =
    begin
      IO.popen('ifconfig'){|fd| fd.readlines}
    rescue
      IO.popen('ipconfig /all'){|fd| fd.readlines}
    end
  candidates = lines.map{|l| re.match( l )[1] rescue nil }.compact
  @mac_address = candidates.first
end

.mac_short ⇒ Object 



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# File 'lib/findme.rb', line 193

def self.mac_short
  self.mac.split(":").join("")
end

.register(service_name, port, txt = "", type = '_tcp', protocol = "ipv4") ⇒ Object

register a new service to the folder



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# File 'lib/findme.rb', line 145

def self.register service_name,  port, txt="", type = '_tcp', protocol="ipv4"
  txt = ("findme_startup_time=#{Time.now.to_i.to_s}#" + txt).strip
  xml = '<?xml version="1.0" standalone=\'no\'?><!--*-nxml-*-->
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">

<!-- findme generated -->
<!-- This file is part of '+ service_name + '} -->

<service-group>
<name replace-wildcards="yes">%h</name>

<service protocol="' + protocol + '">

  <type>'+ "_#{service_name}.#{type}" +'</type>
  <port>'+ port.to_s + '</port>
  <txt-record>' + txt.to_s + '</txt-record>
</service>
</service-group>'

  File.open(AVAHI_SERVICE_DIR  + service_name + ".service", "w" ){|f| f.write xml}
end

.services ⇒ Object

return all the services running by avahi



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# File 'lib/findme.rb', line 9

def self.services
  files_with_path = Dir.glob(AVAHI_SERVICE_DIR + "*.service")
  files = files_with_path.map{|fwp| fwp.split("/").last}
end

.unregister(service_name) ⇒ Object

Unregister a service, just remove .service file from avahi service directory. result: BOOLEAN, In most cases we don’t care it.



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# File 'lib/findme.rb', line 169

def self.unregister service_name
  service_file = AVAHI_SERVICE_DIR + service_name + ".service"
  if File.exist? service_file
    File.delete service_file
    return true
  end
rescue # Errno::EACCES: Permission denied
  false
end