feat: add option to print X lines

bin/swapus

@@ -21,7 +21,9 @@ $LOAD_PATH << File.expand_path('../../lib', __FILE__)
 require 'optparse'
 require 'swapus'
 
-reverse = false
+options = {
+  reverse: false
+}
 
 OptionParser.new do |opts|
   opts.banner = 'Usage: swapus [options]'
@@ -31,8 +33,12 @@ OptionParser.new do |opts|
     exit 0
   end
 
+  opts.on('-n', '--number N', 'Print the N first lines') do |number|
+    options[:number] = number.to_i
+  end
+
   opts.on('-r', '--reverse', 'Reverse the result order') do
-    reverse = true
+    options[:reverse] = true
   end
 
   opts.on('-v', '--version', 'Show the version') do
@@ -41,4 +47,4 @@ OptionParser.new do |opts|
   end
 end.parse!
 
-SwapUsage.new(reverse).run
+SwapUsage.new(options).run

lib/swapus.rb

@@ -17,9 +17,10 @@
 # under the License.
 
 class SwapUsage
-  def initialize(reverse)
+  def initialize(options)
     @processes = {}
-    @reverse   = reverse
+    @reverse   = options[:reverse]
+    @number    = options[:number]
   end
 
   def get_processes
@@ -35,6 +36,7 @@ class SwapUsage
   def show
     @processes = @processes.sort_by { |_, v| v[:swap] }
     @processes = @processes.reverse if @reverse
+    @processes = @processes.first(@number) if @number
 
     @processes.each do |pid, values|
       puts "#{values[:swap]} kB [#{pid}] #{values[:cmd]}"