Add IO#close_on_exec=

and a test on test/io.rb

src/io.c

@@ -729,7 +729,7 @@ mrb_notimplement(mrb_state *mrb)
 {
   mrb_raise(mrb, E_SCRIPT_ERROR, "unimplemented on this machine");
   
-  return -1;
+  return;
 }
 
 #if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
@@ -737,8 +737,7 @@ mrb_value
 mrb_io_close_on_exec_p(mrb_state *mrb, mrb_value io)
 {
   struct mrb_io *fptr;
-  mrb_value write_io;
-  int fd, ret;
+  int ret;
   
   fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
   if(fptr->fd2 >= 0){
@@ -765,6 +764,54 @@ mrb_f_notimplement(mrb_state *mrb, mrb_value io)
 }
 #endif
 
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
+mrb_value
+mrb_io_set_close_on_exec(mrb_state *mrb, mrb_value io)
+{
+  mrb_bool bool;
+  int flag;
+  struct mrb_io *fptr;
+  int ret;
+
+  mrb_get_args(mrb, "b", &bool);
+  flag = bool ? FD_CLOEXEC : 0;
+
+  fptr = (struct mrb_io *)mrb_get_datatype(mrb, io, &mrb_io_type);
+
+  if(fptr->fd2 >= 0){
+    if ((ret = fcntl(fptr->fd2, F_GETFD)) == -1) mrb_sys_fail(mrb, "F_GETFD failed");
+    if ((ret & FD_CLOEXEC) != flag) {
+      ret = (ret & ~FD_CLOEXEC) | flag;
+      ret = fcntl(fptr->fd2, F_SETFD, ret);
+      
+      if (ret == -1) mrb_sys_fail(mrb, "F_SETFD failed");
+    }
+  }
+
+  if(fptr->fd < 0){
+    mrb_raise(mrb, E_IO_ERROR, "closed stream");
+  } else {
+    if ((ret = fcntl(fptr->fd, F_GETFD)) == -1) mrb_sys_fail(mrb, "F_GETFD failed");
+    if ((ret & FD_CLOEXEC) != flag) {
+      ret = (ret & ~FD_CLOEXEC) | flag;
+      ret = fcntl(fptr->fd, F_SETFD, ret);
+      if (ret == -1) mrb_sys_fail(mrb, "F_SETFD failed");
+    }
+  }
+
+  return mrb_nil_value();
+}
+#else
+#define mrb_io_close_on_exec mrb_f_notimplement
+mrb_f_notimplement(mrb_state *mrb, mrb_value io)
+{   
+	mrb_notimplement();
+
+  return -1;
+}
+#endif
+
+
 void
 mrb_init_io(mrb_state *mrb)
 {
@@ -791,7 +838,7 @@ mrb_init_io(mrb_state *mrb)
   mrb_define_method(mrb, io, "fileno",     mrb_io_fileno,     MRB_ARGS_NONE());
 
   mrb_define_method(mrb, io, "close_on_exec?",    mrb_io_close_on_exec_p,      MRB_ARGS_NONE());
-/*  mrb_define_method(mrb, io, "close_on_exec=",    mrb_io_set_close_on_exec,    MRB_ARGS_REQ(1));*/
+  mrb_define_method(mrb, io, "close_on_exec=",    mrb_io_set_close_on_exec,    MRB_ARGS_REQ(1));
 
   mrb_gv_set(mrb, mrb_intern_cstr(mrb, "$/"), mrb_str_new_cstr(mrb, "\n"));
 }

test/io.rb

@@ -1,6 +1,8 @@
 ##
 # IO Test
 
+print "test start\n"
+
 assert('IO TEST SETUP') do
   MRubyIOTestUtil.io_test_setup
 end
@@ -342,6 +344,50 @@ assert('IO#fileno') do
   io.closed?
 end
 
+assert('IO#close_on_exec') do 
+  fd = IO.sysopen $mrbtest_io_wfname, "w"
+  io = IO.new fd, "w"
+  begin 
+    # IO.sysopen opens a file descripter without O_CLOEXEC flag.
+    assert_equal(false, io.close_on_exec?)
+  rescue ScriptError
+    skip "IO\#close_on_exec is not implemented."
+  end
+
+  io.close_on_exec = true
+  assert_equal(true, io.close_on_exec?)
+  io.close_on_exec = false
+  assert_equal(false, io.close_on_exec?)
+  io.close_on_exec = true
+  assert_equal(true, io.close_on_exec?)
+  
+  io.close
+  io.closed?
+
+  # # Use below when IO.pipe is implemented.
+  # begin 
+  #   r, w = IO.pipe
+  #   assert_equal(false, r.close_on_exec?)
+  #   r.close_on_exec = true
+  #   assert_equal(true, r.close_on_exec?)
+  #   r.close_on_exec = false
+  #   assert_equal(false, r.close_on_exec?)
+  #   r.close_on_exec = true
+  #   assert_equal(true, r.close_on_exec?)
+
+  #   assert_equal(false, w.close_on_exec?)
+  #   w.close_on_exec = true
+  #   assert_equal(true, w.close_on_exec?)
+  #   w.close_on_exec = false
+  #   assert_equal(false, w.close_on_exec?)
+  #   w.close_on_exec = true
+  #   assert_equal(true, w.close_on_exec?)
+  # ensure
+  #   r.close unless r.closed?
+  #   w.close unless w.closed?
+  # end
+end
+
 assert('`cmd`') do
   assert_equal `echo foo`, "foo\n"
 end