added resize only command for gitLab

bin/resizeOnly

+#!/usr/bin/env ruby
+
+require 'watchAndResize'
+puts WatchAndResize.resizeOnly(ARGV[0])
\ No newline at end of file

jekyll-img-srcset.gemspec

 Gem::Specification.new do |spec|
     spec.name          = "jekyll-img-srcset"
-    spec.version       = "0.3.0"
+    spec.version       = "0.3.1"
     spec.authors       = ["Jan-Philipp Stauffert"]
     spec.email         = ["jan-philipp.stauffert@uni-wuerzburg.de"]
 
@@ -22,5 +22,6 @@ Gem::Specification.new do |spec|
     spec.add_development_dependency "bundler", "~> 1.16"
     spec.add_development_dependency "rake", "~> 12.0"
     spec.executables << 'war'
+    spec.executables << 'resizeOnly'
 end
   

lib/watchAndResize.rb

@@ -3,6 +3,33 @@ require 'mini_magick'
 require 'parallel'
 
 class WatchAndResize
+  
+  def self.resizeOnly(argv)
+    images = Dir.glob("./assets/images/**/*.{jpg,JPG,jpeg,JPEG,png,PNG}")
+    
+    puts "Checking and resizing './assets/images' if necessary withOUT watching files."
+    STDOUT.flush
+    
+    start = Time.now
+    
+    Parallel.each(images) do |source_path|
+  		destinations = generate_destinations(source_path.gsub("assets/images/", ""), [320, 640, 844, 1208, 1688], "./public", "./assets/images")
+  		min_width_path = destinations[0][1]
+  		#puts "processing: #{source_path}, mtimes: #{File.mtime(min_width_path)} ... #{File.mtime(source_path)}"
+		puts "checking: #{source_path}"
+  		if (not File.file?(min_width_path)) || (File.mtime(min_width_path) < File.mtime(source_path))
+  			resize_image(source_path.gsub("assets/images/", ""), [320, 640, 844, 1208, 1688], "./public", "./assets/images")	
+  		end
+  		#puts "destinations: #{min_width_path}"
+  		#STDOUT.flush
+	end
+    
+    delta = Time.now - start
+    
+    puts "Checked and resized './assets/images' if necessary in  #{delta} seconds."
+    STDOUT.flush  
+  end
+  
   def self.awesome(argv)
     
     images = Dir.glob("./assets/images/**/*.{jpg,JPG,jpeg,JPEG,png,PNG}")