Functionality for eznet to check process on port

.gitignore

@@ -0,0 +1,2 @@
+*.swp
+eznet

ltnp/ltnp_operator.cr

@@ -1,16 +1,18 @@
 require "./ltnp_record"
 
 class LtnpOperator
-  def initialize(_cmd_output : String)
-	@cmd_output = _cmd_output
-	records = @cmd_output.each_line
+  def initialize(cmd_output : String)
+	records = cmd_output.each_line
 	records = records.each.select(/^tcp/)
 	@ltnp_records = Array(LtnpRecord).new
 	records.each { |s| @ltnp_records << LtnpRecord.new s }
   end
 
   def say_hi
-	puts @cmd_output
-	puts @ltnp_records.to_s
+	@ltnp_records.each { |r| puts r.to_s }
+  end
+
+  def get_port_record(port : String) : LtnpRecord | Nil
+	@ltnp_records.find { |r| r.port == port }
   end
 end

ltnp/ltnp_record.cr

@@ -1,8 +1,53 @@
 require "../modules/record_helpers"
 
 class LtnpRecord
+  getter proto : String 
+  getter state : String
+  getter address : String
+  getter port : String
+  getter f_address : String
+  getter f_port : String
+  getter state : String
+  getter pid : String
+  getter p_name : String
+
   def initialize(record : String)
-	@str_arr = RecordHelpers.clean_record(record)
+	ser_record = RecordHelpers.clean_record(record)
+	@proto = ser_record[0]
+	@address, @port = ser_address_port ser_record[3].split(':')
+	@f_address, @f_port = ser_address_port ser_record[4].split(':')
+	@state = ser_record[5]
+	@pid, @p_name = ser_pid_p_name ser_record[6]
+  end
 
+  def to_s
+	puts "%s, " * 8 % [
+	  @proto, @state, @address, @port, 
+	  @f_address, @f_port, @pid, @p_name
+	]
+  end
+
+  def ser_address_port(address_port : Array) : {String, String}
+	address = String.new
+	port = String.new
+	unless address_port.size > 2
+	  address = address_port[0]
+	  port = address_port[1]
+	else
+	  port = address_port[-1]
+	end
+	{address, port}
   end
+
+  def ser_pid_p_name(pid_pro_str : String) : {String, String}
+	pid = String.new
+	p_name = String.new
+	unless pid_pro_str == "-"
+	  pid_pro = pid_pro_str.split('/')
+	  pid = pid_pro[0]
+	  p_name = pid_pro[1]
+	end
+	{pid, p_name}
+  end
+    
 end

main.cr

@@ -15,10 +15,20 @@ OptionParser.parse do |parser|
 	exit
   end
 
+  parser.on "-c PORT", "--check-port=PORT", "Get the process name and ID of process on port" do |port|
+	ltnp_operator = NetstatRunner.run_ltnp	
+	record = ltnp_operator.get_port_record port
+	unless record.nil?
+	  puts "Port: %s, Process: %s" % [record.port, record.p_name]
+	else
+	  puts "No processes found on port %s" % port
+	end
+	exit
+  end
+
   parser.on "-k", "--kill-port", "Kill process on port" do
-	output = NetstatRunner.run_ltnp 
-	ltnp_parser = LtnpOperator.new output
-	ltnp_parser.say_hi
+	ltnp_operator = NetstatRunner.run_ltnp	
+	ltnp_operator.say_hi
 	exit
   end
 end

modules/netstat_runner.cr

@@ -1,7 +1,7 @@
 module NetstatRunner
-  def self.run_ltnp() 
+  def self.run_ltnp() : LtnpOperator
 	io = IO::Memory.new
-	Process.run("netstat -ltnp", shell: true, output: io)
-	io.to_s
+	Process.run("sudo netstat -ltnp", shell: true, output: io)
+	LtnpOperator.new io.to_s
   end
 end

spec/ltnp/ltnp_operator_spec.cr

@@ -0,0 +1,19 @@
+require "spec"
+require "../../ltnp/ltnp_operator.cr"
+
+describe LtnpOperator do
+  sut = LtnpOperator.new File.read("./spec/input/ltnp_example.txt")
+
+  describe "#get_port_record" do
+	existing_port = "8081"
+	nonsense_port = "1234"
+
+	it "should find record when port exists" do
+	  sut.get_port_record(existing_port).nil?.should be_false
+	end
+
+	it "should not find record when port doesn't exist" do
+	  sut.get_port_record(nonsense_port).nil?.should be_true
+	end
+  end
+end

spec/ltnp/ltnp_record_spec.cr

@@ -0,0 +1,29 @@
+require "spec"
+require "../../ltnp/ltnp_record.cr"
+
+describe LtnpRecord do
+  sut_normal = LtnpRecord.new "tcp        0      0 127.0.0.1:8081          0.0.0.0:*               LISTEN      69/myproc"      
+  sut_address = LtnpRecord.new "tcp        0      0 :::8081          0.0.0.0:*               LISTEN      69/myproc"  
+  sut_process = LtnpRecord.new "tcp        0      0 :::8081          0.0.0.0:*               LISTEN      -"  
+
+  it "should have expected properties under normal circumstance" do
+	sut_normal.proto.should eq("tcp")
+	sut_normal.address.should eq("127.0.0.1")
+	sut_normal.port.should eq("8081")
+	sut_normal.f_address.should eq("0.0.0.0")
+	sut_normal.f_port.should eq("*")
+	sut_normal.state.should eq("LISTEN")
+	sut_normal.pid.should eq("69")
+	sut_normal.p_name.should eq("myproc")
+  end
+
+  it "should have expected properties when Local Address column is edge case" do
+	sut_address.address.empty?.should be_true
+	sut_address.port.should eq("8081")
+  end
+
+  it "should have expected properties when PID/ProcessName column is edge case" do
+	sut_process.pid.empty?.should be_true
+	sut_process.p_name.empty?.should be_true
+  end
+end