Add cwd='/path/to/foo' support to luxio.subprocess.spawn

1 files changed, 15 insertions, 0 deletions

diff --git a/luxio/subprocess.lua b/luxio/subprocess.lua
index d0a7c91..3da5993 100644
--- a/luxio/subprocess.lua
+++ b/luxio/subprocess.lua
@@ -45,6 +45,9 @@
 -- If you want the child (during pre-exec) to close additional FDs then
 -- you can specify them in a table called close_in_child
 --
+-- If you want to change directory before exec in the child, you can pass
+-- cwd="/some/path".
+--
 -- spawn_simple has one additional tweak.  If 'stdin' is provided as
 -- a string then it will automatically write that string to the stdin
 -- of the child (and close the FD afterwards) for you automatically.
@@ -92,6 +95,8 @@ local dup2 = l.dup2
 local fcntl = l.fcntl
 local bclear = l.bit.bclear
 local wrap_fd = sio.wrap_fd
+local chdir = sio.chdir
+local stderr_fh = sio.stderr
 local setenv = l.setenv
 local unsetenv = l.unsetenv
 local _exit = l._exit
@@ -295,6 +300,16 @@ local function _spawn(t)
 	 end
       end
 
+      -- Change directory if needed
+      if proc.args.cwd then
+	 local cwd = tostring(proc.args.cwd)
+	 local ret, err = chdir(cwd)
+	 if ret ~= 0 then
+	    stderr_fh:write("chdir(" .. cwd .. "): " .. err)
+	    _exit(1)
+	 end
+      end
+
       -- Run the child process
       exec_fn(exe, unpack(proc.args))