Add an 'inotify' sample for linux

1 files changed, 59 insertions, 0 deletions

diff --git a/samples/inotify.rb b/samples/inotify.rb
new file mode 100644
index 0000000..7d3fc27
--- /dev/null
+++ b/samples/inotify.rb
@@ -0,0 +1,59 @@
+require 'rubygems'
+require 'ffi'
+module Inotify
+  extend FFI::Library
+  class Event < FFI::Struct
+    layout \
+      :wd, :int,
+      :mask, :uint,
+      :cookie, :uint,
+      :len, :uint
+  end
+  attach_function :init, :inotify_init, [ ], :int
+  attach_function :add_watch, :inotify_add_watch, [ :int, :string, :uint ], :int
+  attach_function :rm_watch, :inotify_rm_watch, [ :int, :uint ], :int
+  attach_function :read, [ :int, :buffer_out, :uint ], :int
+  IN_ACCESS=0x00000001
+  IN_MODIFY=0x00000002
+  IN_ATTRIB=0x00000004
+  IN_CLOSE_WRITE=0x00000008
+  IN_CLOSE_NOWRITE=0x00000010
+  IN_CLOSE=(IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)
+  IN_OPEN=0x00000020
+  IN_MOVED_FROM=0x00000040
+  IN_MOVED_TO=0x00000080
+  IN_MOVE= (IN_MOVED_FROM | IN_MOVED_TO)
+  IN_CREATE=0x00000100
+  IN_DELETE=0x00000200
+  IN_DELETE_SELF=0x00000400
+  IN_MOVE_SELF=0x00000800
+  # Events sent by the kernel.
+  IN_UNMOUNT=0x00002000
+  IN_Q_OVERFLOW=0x00004000
+  IN_IGNORED=0x00008000
+  IN_ONLYDIR=0x01000000
+  IN_DONT_FOLLOW=0x02000000
+  IN_MASK_ADD=0x20000000
+  IN_ISDIR=0x40000000
+  IN_ONESHOT=0x80000000
+  IN_ALL_EVENTS=(IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE \
+                          | IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM \
+                          | IN_MOVED_TO | IN_CREATE | IN_DELETE \
+                          | IN_DELETE_SELF | IN_MOVE_SELF)
+
+end
+if $0 == __FILE__
+  fd = Inotify.init
+  puts "fd=#{fd}"
+  wd = Inotify.add_watch(fd, "/tmp/", Inotify::IN_ALL_EVENTS)
+  fp = IO.for_fd(fd)
+  puts "wfp=#{fp}"
+  while true
+    buf = FFI::Buffer.alloc_out(Inotify::Event.size + 4096, 1, false)
+    ev = Inotify::Event.new buf
+    ready = IO.select([ fp ], nil, nil, nil)
+    n = Inotify.read(fd, buf, buf.total)
+    puts "Read #{n} bytes from inotify fd"
+    puts "event.wd=#{ev[:wd]} mask=#{ev[:mask]} len=#{ev[:len]} name=#{ev[:len] > 0 ? buf.get_string(16) : 'unknown'}"
+  end
+end
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