diff --git a/Makefile b/Makefile
index 37b6f14..76334b5 100755
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,11 @@ INCLUDES = -I$(LUA)/include
 
 LUA = /home/mark/src/lang/lua/lua-5.1-rc1
 
-mingw:; $(MAKE) -C w32api ex.dll
+default:; echo Choose platform: mingw cygwin posix
+all: mingw cygwin
 
+mingw:; $(MAKE) -C w32api ex.dll
 cygwin:; $(MAKE) -C posix ex.dll
+posix:; $(MAKE) -C posix ex.so
+
 #"EX_LIB=ex.so" "DEFINES=-D_XOPEN_SOURCE=600"
diff --git a/posix/ex.c b/posix/ex.c
index 43a689f..7ec5a87 100755
--- a/posix/ex.c
+++ b/posix/ex.c
@@ -289,6 +289,7 @@ static int ex_unlock(lua_State *L)
 	return ex_lock(L);
 }
 
+
 static int closeonexec(int d)
 {
 	int fl = fcntl(d, F_GETFD);
diff --git a/posix/posix_spawn.c b/posix/posix_spawn.c
index 9a80628..cc69844 100755
--- a/posix/posix_spawn.c
+++ b/posix/posix_spawn.c
@@ -8,8 +8,6 @@
 
 #include "posix_spawn.h"
 
-#define nelemof(A) (sizeof A / sizeof *A)
-
 int posix_spawn_file_actions_init(posix_spawn_file_actions_t *act)
 {
 	act->dups[0] = act->dups[1] = act->dups[2] = -1;
@@ -22,11 +20,11 @@ int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *act, int d, int
 		errno = EBADF;
 		return -1;
 	}
-	if (2 < d) {
+	if (2 < n) {
 		errno = EINVAL;
 		return -1;
 	}
-	act->dups[d] = n;
+	act->dups[n] = d;
 	return 0;
 }
 
@@ -46,20 +44,19 @@ int posix_spawnp(pid_t *restrict ppid,
 		return EINVAL;
 	if (attrp)
 		return EINVAL;
-	/* check act actions? */
 	switch (*ppid = fork()) {
 	case -1: return -1;
 	default: return 0;
 	case 0:
 		if (act) {
-			size_t i;
-			for (i = 0; i < nelemof(act->dups); i++)
-				if (act->dups[i] > -1)
-					dup2(i, act->dups[i]);
+			int i;
+			for (i = 0; i < 3; i++)
+				if (act->dups[i] != -1 && -1 == dup2(act->dups[i], i))
+					_exit(111);
 		}
 		environ = (char **)envp;
 		execvp(path, argv);
-		_exit(EXIT_FAILURE);
+		_exit(111);
 		/*NOTREACHED*/
 	}
 }
diff --git a/posix/spawn.c b/posix/spawn.c
index 5c492a1..e1cc7f7 100755
--- a/posix/spawn.c
+++ b/posix/spawn.c
@@ -1,15 +1,12 @@
-#include <assert.h>
-
 #include <lua.h>
-#include <lualib.h>
 #include <lauxlib.h>
 
 #include <unistd.h>
 #include <sys/wait.h>
-#ifndef MISSING_POSIX_SPAWN
-#include <spawn.h>
-#else
+#if MISSING_POSIX_SPAWN
 #include "posix_spawn.h"
+#else
+#include <spawn.h>
 #endif
 
 #include "spawn.h"
@@ -21,7 +18,6 @@ struct spawn_params {
 };
 
 extern int push_error(lua_State *L);
-extern FILE *check_file(lua_State *L, int idx, const char *argname);
 
 struct spawn_params *spawn_param_init(lua_State *L)
 {
@@ -105,7 +101,6 @@ void spawn_param_redirect(struct spawn_params *p, const char *stdname, FILE *f)
 	case 'o': d = STDOUT_FILENO; break;
 	case 'e': d = STDERR_FILENO; break;
 	}
-	debug("duplicating %d to %d\n", fileno(f), d);
 	posix_spawn_file_actions_adddup2(&p->redirect, fileno(f), d);
 }
 
@@ -135,9 +130,6 @@ int spawn_param_execute(struct spawn_params *p)
 	return ret != 0 ? push_error(L) : 1;
 }
 
-
-extern int push_error(lua_State *L);
-
 /* proc -- exitcode/nil error */
 int process_wait(lua_State *L)
 {
diff --git a/w32api/ex.c b/w32api/ex.c
index d0ccde8..87ba0cc 100755
--- a/w32api/ex.c
+++ b/w32api/ex.c
@@ -350,7 +350,6 @@ static int ex_unlock(lua_State *L)
 }
 
 
-/* -- LUA_FILEHANDLE file file */
 static int make_pipe(FILE **i, FILE **o)
 {
 	HANDLE ph[2];
diff --git a/w32api/spawn.c b/w32api/spawn.c
index 7932f5a..978a2fe 100755
--- a/w32api/spawn.c
+++ b/w32api/spawn.c
@@ -1,19 +1,17 @@
 #include <stdlib.h>
 
 #include <lua.h>
-#include <lualib.h>
 #include <lauxlib.h>
 
 #include <windows.h>
 
 #include "spawn.h"
 
-#include <assert.h>
-#define debug(...) fprintf(stderr, __VA_ARGS__)
-#include "../lds.c"
+#define debug(...) /* fprintf(stderr, __VA_ARGS__) */
+#define debug_stack(L) /* #include "../lds.c" */
 
-extern HANDLE get_handle(FILE *f);
 extern int push_error(lua_State *L);
+extern HANDLE get_handle(FILE *f);
 
 static int needs_quoting(const char *s)
 {
@@ -41,7 +39,6 @@ struct spawn_params *spawn_param_init(lua_State *L)
 	return p;
 }
 
-/* filename ... */
 void spawn_param_filename(struct spawn_params *p, const char *filename)
 {
 	p->cmdline = filename;
@@ -82,7 +79,7 @@ void spawn_param_args(struct spawn_params *p)
 	p->cmdline = lua_tostring(L, -1);
 }
 
-/* ... envtab */
+/* ... envtab/nil */
 void spawn_param_env(struct spawn_params *p)
 {
 	lua_State *L = p->L;
@@ -126,8 +123,8 @@ void spawn_param_redirect(struct spawn_params *p, const char *stdname, FILE *f)
 }
 
 struct process {
-    int status;
-    HANDLE hProcess;
+	int status;
+	HANDLE hProcess;
 	DWORD dwProcessId;
 };