Module: FunkySystem

Defined in:
lib/funkysystem.rb,
lib/funkysystem/version.rb

Defined Under Namespace

Classes: ProgramOutput

Constant Summary collapse

VERSION = 
"0.0.1"

Class Method Summary collapse

Class Method Details

.find_exec(name) ⇒ Object 



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# File 'lib/funkysystem.rb', line 50

def self.find_exec(name)
	ENV["PATH"].split(/:/).each do |bin|
		path = File.join(File.expand_path(bin), name)
		begin
			stat = File.stat(path)
			if stat.executable? && stat.file?
				return path
			end
		rescue Errno::ENOENT
		end
	end
	nil
end

.output_to_writeable_io(out, &block) ⇒ Object 



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# File 'lib/funkysystem.rb', line 24

def self.output_to_writeable_io(out, &block)
	case out
	when String
		File.open(out, 'w', &block)
	when IO
		yield(out)
	#when nil
	else
		File.open('/dev/null', 'w', &block)
	end
end

.redirect_output(options = {}, &block) ⇒ Object

Run block, but with output redirected to elsewhere

Parameters:

  • outputs (Hash) —

    :stdout & :stderr - either an IO object, a filename or nil to redirect stream to /dev/null



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# File 'lib/funkysystem.rb', line 8

def self.redirect_output(options = {}, &block)
	stderr_dup = STDERR.dup
	stdout_dup = STDOUT.dup
	begin
		output_to_writeable_io(options[:stdout]) do |out|
			STDOUT.reopen(out)
			output_to_writeable_io(options[:stderr]) do |err|
				STDERR.reopen(err)
				block.call
			end
		end
	ensure
		STDERR.reopen(stderr_dup)
		STDOUT.reopen(stdout_dup)
	end
end

.run(cmd, stdin = nil) ⇒ Object 



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# File 'lib/funkysystem.rb', line 63

def self.run(cmd, stdin=nil)
	fps = {
		:stdout => IO.pipe,
		:stderr => IO.pipe
	}
	
	fps[:stdin] = IO.pipe if stdin
	
	fps.each do |key,fpa|
		class << fpa
			alias :reader :first
			alias :writer :last
		end
	end
	
	pid = fork do
		keep = [STDERR, STDOUT, STDIN] + fps.values.flatten
		ObjectSpace.each_object(IO) { |io|
			begin
				io.close() unless keep.include?(io)
			rescue Exception
			end
		}
		if fps[:stdin]
			fps[:stdin].writer.close
			STDIN.reopen(fps[:stdin].reader)
			fps[:stdin].reader.close
		else
			# No input - child shouldn't
			# be allowed to expect any...
			STDIN.close()
		end
		
		fps[:stdout].reader.close
		STDOUT.reopen(fps[:stdout].writer)
		fps[:stdout].writer.close
		
		fps[:stderr].reader.close
		STDERR.reopen(fps[:stderr].writer)
		fps[:stderr].writer.close
		
		exec(* ( cmd.is_a?(Array) ? cmd : [cmd] ) )
	end
	
	fps[:stderr].writer.close
	fps[:stdout].writer.close
	
	if fps[:stdin]
		fps[:stdin].reader.close 
		out_fds = [fps[:stdin].writer]
	else
		out_fds = []
	end
	
	in_fds  = [fps[:stderr].reader, fps[:stdout].reader]
	all_fds = in_fds + out_fds
	
	all_fds.each { |fd| fd.nonblock = true }
	
	stdout = ''
	stderr = ''
	exited = nil
	exit_time = nil
	
	until exited && (in_fds.all? { |fd| fd.closed? or fd.eof? } || exit_time < (Time.now.to_i - 3) )
		exited ||= Process.waitpid2(pid, Process::WNOHANG)
		exit_time ||= Time.now.to_i if exited
		begin
			rd, wr, er = select(in_fds, out_fds, all_fds, 0.05)
		rescue IOError
			[in_fds, out_fds, all_fds].each { |grp|
				grp.reject!{ |fd| fd.closed? }
			}
			rd = wr = er = nil
		end
		wr.each do |fd|
			begin
				case fd
				when fps[:stdin].writer
					size = fd.syswrite(stdin)
					stdin = stdin[size..-1]
					if stdin.empty?
						fd.close
						out_fds = []
						stdin = nil
					end
				end
			rescue Errno::EPIPE, IOError
			end
		end if wr.respond_to?(:each)
					
		rd.each do |fd|
			begin
				case fd
				when fps[:stderr].reader
					stderr << fd.sysread(4096 * 4)
				when fps[:stdout].reader
					stdout << fd.sysread(4096 * 4)
				end
			rescue Errno::EPIPE, IOError
			end
		end if rd.respond_to?(:each)

	end
	
	ProgramOutput.new(pid, exited.last, stdout, stderr, stdin)
end