Add Linux man pages documentation

docs/file-scrapers.md

@@ -142,6 +142,13 @@ $GS = '/usr/local/opt/ghostscript/bin/gs';	# GhostScript
 ```
 </details>
 
+## Man
+
+```sh
+wget --recursive --no-parent https://man7.org/linux/man-pages/
+mv man7.org/linux/man-pages/ docs/man/
+```
+
 ## NumPy
 
 ```sh

lib/docs/filters/man/clean_html.rb

@@ -0,0 +1,19 @@
+module Docs
+  class Man
+    class CleanHtmlFilter < Filter
+      def call
+        css('.page-top').remove
+        css('.nav-bar').remove
+        css('.nav-end').remove
+        css('.sec-table').remove
+        css('a[href="#top_of_page"]').remove
+        css('.end-man-text').remove
+        css('.start-footer').remove
+        css('.footer').remove
+        css('.end-footer').remove
+        css('form[action="https://www.google.com/search"]').remove
+        doc
+      end
+    end
+  end
+end

lib/docs/filters/man/entries.rb

@@ -0,0 +1,29 @@
+module Docs
+  class Man
+    class EntriesFilter < Docs::EntriesFilter
+
+      def get_name
+        at_css('h1').content.sub(' — Linux manual page', '')
+      end
+
+      def get_type
+        'Linux manual page'
+      end
+
+      def entries
+        return super unless slug == 'dir_by_project'
+        type0 = nil
+        return css('*').each_with_object [] do |node, entries|
+          if node.name == 'h2'
+            type0 = node.content
+          elsif node.name == 'a' and node['href'] and node['href'].start_with?('man') and type0
+            name = node.content + node.next_sibling.content
+            path = node['href']
+            entries << Entry.new(name, path, type0)
+          end
+        end
+      end
+
+    end
+  end
+end

lib/docs/scrapers/man.rb

@@ -0,0 +1,16 @@
+module Docs
+  class Man < FileScraper
+    self.name = 'Linux man pages'
+    self.type = 'simple'
+    self.slug = 'man'
+	  self.base_url = "https://man7.org/linux/man-pages/"
+	  self.initial_paths = %w(dir_by_project.html)
+    self.links = {
+      home: 'https://man7.org/linux/man-pages/',
+    }
+    html_filters.push 'man/entries', 'man/clean_html'
+    options[:attribution] = <<-HTML
+	  ...
+    HTML
+  end
+end