daemonize.rb in daemons-0.4.0

- old
+ new

@@ -110,18 +110,115 @@
     end
   end
   module_function :safefork
   
   
+  def simulate(logfile_name = nil)
+    # NOTE: STDOUT and STDERR will not be redirected to the logfile!
+    
+    Dir.chdir "/"   # Release old working directory
+    File.umask 0000 # Insure sensible umask
+
+    # Make sure all file descriptors are closed
+    ObjectSpace.each_object(IO) do |io|
+      unless [STDIN, STDOUT, STDERR].include?(io)
+        begin
+          unless io.closed?
+            io.close
+          end
+        rescue ::Exception
+        end
+      end
+    end
+
+    # Free file descriptors and
+    # point them somewhere sensible
+    # STDOUT/STDERR should go to a logfile
+    
+    STDIN.reopen "/dev/null" rescue nil       
+  end
+  module_function :simulate
+  
+  
+  def call_as_daemon(block, logfile_name = nil, oldmode = 0)
+    rd, wr = IO.pipe
+    
+    if tmppid = safefork
+      # parent
+      wr.close
+      pid = rd.read.to_i
+      rd.close
+      
+      Process.waitpid(tmppid)
+      
+      return pid
+    else
+      rd.close
+      
+      # Detach from the controlling terminal
+      unless sess_id = Process.setsid
+        raise Daemons.RuntimeException.new('cannot detach from controlling terminal')
+      end
+  
+      # Prevent the possibility of acquiring a controlling terminal
+      if oldmode.zero?
+        trap 'SIGHUP', 'IGNORE'
+        exit if pid = safefork
+      end
+  
+      wr.write Process.pid
+      wr.close
+      
+      Dir.chdir "/"   # Release old working directory
+      File.umask 0000 # Insure sensible umask
+  
+      # Make sure all file descriptors are closed
+      ObjectSpace.each_object(IO) do |io|
+        unless [STDIN, STDOUT, STDERR].include?(io)
+          begin
+            unless io.closed?
+              io.close
+            end
+          rescue ::Exception
+          end
+        end
+      end
+  
+      # Free file descriptors and
+      # point them somewhere sensible
+      # STDOUT/STDERR should go to a logfile
+      
+      STDIN.reopen "/dev/null" rescue nil       
+      
+      if logfile_name
+        begin
+          STDOUT.reopen logfile_name, "a" 
+        rescue ::Exception
+          STDOUT.reopen "/dev/null" rescue nil
+        end
+      else
+        STDOUT.reopen "/dev/null" rescue nil
+      end
+      
+      STDERR.reopen STDOUT rescue nil    
+    
+      block.call
+      
+      exit
+    end
+  end
+  module_function :call_as_daemon
+  
+  
   # This method causes the current running process to become a daemon
   def daemonize(logfile_name = nil, oldmode=0)
     srand # Split rand streams between spawning and daemonized process
     safefork and exit # Fork and exit from the parent
 
     # Detach from the controlling terminal
     unless sess_id = Process.setsid
-      raise Daemons.RuntimeException.new('cannot detach from controlled terminal')
+      raise Daemons.RuntimeException.new('cannot detach from controlling terminal')
     end
 
     # Prevent the possibility of acquiring a controlling terminal
     if oldmode.zero?
       trap 'SIGHUP', 'IGNORE'
@@ -158,10 +255,9 @@
     else
       STDOUT.reopen "/dev/null" rescue nil
     end
      
     STDERR.reopen STDOUT rescue nil           
-    
     
     return oldmode ? sess_id : 0   # Return value is mostly irrelevant
   end
   module_function :daemonize
   