From mboxrd@z Thu Jan  1 00:00:00 1970
From: chrisw@rice.edu (Christopher Warrington)
Date: Sun,  3 Feb 2008 02:11:12 -0600
Subject: [sup-talk] [PATCH] shell commands are now run in a child process
Message-ID: <1202026272-3432-2-git-send-email-chrisw@rice.edu>

When shelling out, the external command is now run in a child process.
Before the external command is run, all (I hope) of sup's open files are
closed first.

This should fix the ferret "Permission denied" errors on Windows.
---
 lib/sup/buffer.rb |   27 ++++++++++++++++++++++++++-
 1 files changed, 26 insertions(+), 1 deletions(-)

diff --git a/lib/sup/buffer.rb b/lib/sup/buffer.rb
index 4374fa8..7768011 100644
--- a/lib/sup/buffer.rb
+++ b/lib/sup/buffer.rb
@@ -696,11 +696,36 @@ EOS
     draw_screen :refresh => true
   end
 
+  ## There is no good way that I can find the get the maximum fd allowed.
+  ## On the POSIX systems I have played with, 500 seems to be the maximum. On Windows,
+  ## 2048 is the documented maximum (for the C Runtime Library).
+  MAX_FD = 2048
+
   def shell_out command
     @shelled = true
     Ncurses.sync do
       Ncurses.endwin
-      system command
+
+      child_pid = fork
+      if child_pid == nil
+        ## child process
+
+        start_fd = 1 + [STDIN.fileno, STDOUT.fileno, STDERR.fileno].max # don't close these
+	start_fd.upto(MAX_FD) do |fd|
+          begin
+            IO.for_fd(fd).close
+          rescue Errno::EBADF
+            ## fd is not open: ignore and move on
+          end
+        end
+
+        exec(command)
+        ## never gets here
+      else
+        ## sup process
+        Process.waitpid(child_pid, Process::WUNTRACED) # catch an already dead child
+      end
+
       Ncurses.refresh
       Ncurses.curs_set 0
     end
-- 
1.5.3.8