diff --git a/posix/Makefile b/posix/Makefile
index 06531d0..36ee544 100755
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -1,13 +1,19 @@
 CFLAGS = -std=c99 $(WARNINGS) $(DEFINES) $(INCLUDES)
-DEFINES = -D_POSIX_SOURCE -D_XOPEN_SOURCE=600 -D_POSIX_C_SOURCE=200112L -U__STRICT_ANSI__
-INCLUDES = -I$(LUA)/include -I.
+DEFINES = -D_POSIX_SOURCE -D_XOPEN_SOURCE=600 -D_POSIX_C_SOURCE=200112L -U__STRICT_ANSI__ -DMISSING_POSIX_SPAWN
+INCLUDES = -I$(LUA)/include
 WARNINGS = -W -Wall
 #LUA = /home/mark/src/lang/lua/lua-5.1-rc2
 LUA = /home/mark/src/lang/lua/lua51
 
-ex.so: ex.o; $(CC) -shared -o $@ ex.o
+ex-OBJS = ex.o spawn.o
+
+ex.so: $(ex-OBJS); $(CC) -shared -o $@ $(ex-OBJS)
 
 #LIBS = -L$(LUA)/lib -llua51 spawn.a
-ex.dll: ex.o $(LIBS); $(CC) -shared -L$(LUA)/bin/Cygwin -o $@ ex.o spawn.o -llua51
+EXTRA = posix_spawn.o
+ex.dll: $(ex-OBJS) $(LIBS); $(CC) -shared -L$(LUA)/bin/Cygwin -o $@ $(ex-OBJS) $(EXTRA) -llua51
 
+ex.o: ex.c spawn.h
 spawn.o: spawn.c spawn.h
+
+posix_spawn.o: posix_spawn.c posix_spawn.h
diff --git a/posix/ex.c b/posix/ex.c
index 7df891f..f82b2cd 100755
--- a/posix/ex.c
+++ b/posix/ex.c
@@ -11,12 +11,11 @@
 
 #include <unistd.h>
 #include <fcntl.h>
-#include <spawn.h>
-#include <sys/wait.h>
+#include "spawn.h"
 
 
 /* Generally useful function -- what luaL_checkudata() should do */
-static void *luaL_checkuserdata(lua_State *L, int idx, const char *tname)
+void *checkuserdata(lua_State *L, int idx, const char *tname)
 {
     void *ud;
     luaL_argcheck(L, ud = luaL_checkudata(L, idx, tname), idx, tname);
@@ -25,7 +24,7 @@ static void *luaL_checkuserdata(lua_State *L, int idx, const char *tname)
 
 
 /* -- nil error */
-static int push_error(lua_State *L)
+int push_error(lua_State *L)
 {
 	lua_pushnil(L);
 	lua_pushstring(L, strerror(errno));
@@ -148,7 +147,7 @@ static int file_lock(lua_State *L, FILE *f, const char *mode, long offset, long
 /* file mode [offset [length]] -- true/nil error */
 static int ex_lock(lua_State *L)
 {
-	FILE **pf = luaL_checkuserdata(L, 1, LUA_FILEHANDLE);
+	FILE **pf = checkuserdata(L, 1, LUA_FILEHANDLE);
 	const char *mode = luaL_checkstring(L, 2);
 	long offset = luaL_optnumber(L, 3, 0);
 	long length = luaL_optnumber(L, 4, 0);
@@ -188,128 +187,6 @@ static int ex_pipe(lua_State *L)
 }
 
 
-struct spawn_params {
-	lua_State *L;
-	const char *command, **argv, **envp;
-	posix_spawn_file_actions_t file_actions;
-	int has_actions;
-};
-
-/* filename ... */
-static void spawn_param_filename(struct spawn_params *p)
-{
-	/* XXX confusing */
-	p->command = luaL_checkstring(p->L, 1);
-}
-
-/* -- */
-static void spawn_param_defaults(struct spawn_params *p)
-{
-	p->argv = lua_newuserdata(p->L, 2 * sizeof *p->argv);
-	p->argv[0] = p->command;
-	p->argv[1] = 0;
-	p->envp = (const char **)environ;
-	p->has_actions = 0;
-}
-
-/* Converts a Lua array of strings to a null-terminated array of char pointers.
- * Pops a (0-based) Lua array and replaces it with a userdatum which is the
- * null-terminated C array of char pointers.  The elements of this array point
- * to the strings in the Lua array.  These strings should be associated with
- * this userdatum via a weak table for GC purposes, but they are not here.
- * Therefore, any function which calls this must make sure that these strings
- * remain available until the userdatum is thrown away.
- */
-/* ... array -- ... vector */
-static const char **make_vector(lua_State *L)
-{
-	size_t i, n = lua_objlen(L, -1);
-	const char **vec = lua_newuserdata(L, (n + 2) * sizeof *vec);
-	                                   /* ... arr vec */
-	for (i = 0; i <= n; i++) {
-		lua_rawgeti(L, -2, i);         /* ... arr vec elem */
-		vec[i] = lua_tostring(L, -1);
-		lua_pop(L, 1);                 /* ... arr vec */
-	}
-	vec[n + 1] = 0;
-	lua_replace(L, -2);                /* ... vector */
-	return vec;
-}
-
-/* ... argtab */
-static void spawn_param_args(struct spawn_params *p)
-{
-	const char **argv = make_vector(p->L);
-	if (!argv[0]) argv[0] = p->command;
-	p->argv = argv;
-}
-
-/* ... envtab/nil */
-static void spawn_param_env(struct spawn_params *p)
-{
-	size_t i = 0;
-	luaL_Buffer estr;
-	if (lua_isnil(p->L, -1)) {
-		p->envp = (const char **)environ;
-		return;
-	}
-	luaL_buffinit(p->L, &estr);
-	lua_newtable(p->L);                    /* ... envtab arr */
-	lua_pushnil(p->L);                     /* ... envtab arr nil */
-	for (i = 0; lua_next(p->L, -3); i++) { /* ... envtab arr k v */
-		luaL_prepbuffer(&estr);
-		lua_pushvalue(p->L, -2);           /* ... envtab arr k v k */
-		luaL_addvalue(&estr);
-		luaL_putchar(&estr, '=');
-		lua_pop(p->L, 1);                  /* ... envtab arr k v */
-		luaL_addvalue(&estr);
-		lua_pop(p->L, 1);                  /* ... envtab arr k */
-		luaL_pushresult(&estr);            /* ... envtab arr k estr */
-		lua_rawseti(p->L, -3, i);          /* ... envtab arr[n]=estr k */
-	}                                      /* ... envtab arr */
-	lua_replace(p->L, -2);                 /* ... arr */
-	make_vector(p->L);                     /* ... arr */
-}
-
-/* _ opts ... */
-static int get_redirect(struct spawn_params *p, const char *stdname, int descriptor)
-{
-	int ret;
-	lua_getfield(p->L, 2, stdname);
-	if ((ret = !lua_isnil(p->L, -1)))
-		/* XXX luaL_checkuserdata is confusing here */
-		posix_spawn_file_actions_adddup2(&p->file_actions, 
-			fileno(luaL_checkuserdata(p->L, -1, LUA_FILEHANDLE)), descriptor);
-	lua_pop(p->L, 1);
-	return ret;
-}
-
-/* _ opts ... */
-static void spawn_param_redirects(struct spawn_params *p)
-{
-	posix_spawn_file_actions_init(&p->file_actions);
-	p->has_actions = 1;
-	get_redirect(p, "stdin", STDIN_FILENO);
-	get_redirect(p, "stdout", STDOUT_FILENO);
-	get_redirect(p, "stderr", STDERR_FILENO);
-}
-
-#define PROCESS_HANDLE "process"
-struct process {
-	int status;
-	pid_t pid;
-};
-
-static int spawn_param_execute(struct spawn_params *p, struct process *proc)
-{
-	int ret;
-	proc->status = -1;
-	ret = posix_spawnp(&proc->pid, p->command, &p->file_actions, 0, (char *const *)p->argv, (char *const *)p->envp);
-	if (p->has_actions)
-		posix_spawn_file_actions_destroy(&p->file_actions);
-	return ret == 0;
-}
-
 /* filename [args-opts] -- true/nil,error */
 /* args-opts -- true/nil,error */
 static int ex_spawn(lua_State *L)
@@ -381,20 +258,6 @@ static int ex_spawn(lua_State *L)
 	return 1; /* ... proc */
 }
 
-/* proc -- exitcode/nil error */
-static int process_wait(lua_State *L)
-{
-	struct process *p = luaL_checkuserdata(L, 1, PROCESS_HANDLE);
-	if (p->status == -1) {
-		int status;
-		if (-1 == waitpid(p->pid, &status, 0))
-			return push_error(L);
-		p->status = WEXITSTATUS(status);
-	}
-	lua_pushnumber(L, p->status);
-	return 1;
-}
-
 
 static const luaL_reg ex_iolib[] = {
 	{"pipe",  ex_pipe},
diff --git a/posix/spawn.c b/posix/spawn.c
new file mode 100755
index 0000000..63eda45
--- /dev/null
+++ b/posix/spawn.c
@@ -0,0 +1,135 @@
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include "spawn.h"
+
+extern int push_error(lua_State *L);
+extern void *checkuserdata(lua_State *L, int index, const char *name);
+
+/* filename ... */
+void spawn_param_filename(struct spawn_params *p)
+{
+	/* XXX confusing */
+	p->command = luaL_checkstring(p->L, 1);
+}
+
+/* -- */
+void spawn_param_defaults(struct spawn_params *p)
+{
+	p->argv = lua_newuserdata(p->L, 2 * sizeof *p->argv);
+	p->argv[0] = p->command;
+	p->argv[1] = 0;
+	p->envp = (const char **)environ;
+	p->has_actions = 0;
+}
+
+/* Converts a Lua array of strings to a null-terminated array of char pointers.
+ * Pops a (0-based) Lua array and replaces it with a userdatum which is the
+ * null-terminated C array of char pointers.  The elements of this array point
+ * to the strings in the Lua array.  These strings should be associated with
+ * this userdatum via a weak table for GC purposes, but they are not here.
+ * Therefore, any function which calls this must make sure that these strings
+ * remain available until the userdatum is thrown away.
+ */
+/* ... array -- ... vector */
+static const char **make_vector(lua_State *L)
+{
+	size_t i, n = lua_objlen(L, -1);
+	const char **vec = lua_newuserdata(L, (n + 2) * sizeof *vec);
+	                                   /* ... arr vec */
+	for (i = 0; i <= n; i++) {
+		lua_rawgeti(L, -2, i);         /* ... arr vec elem */
+		vec[i] = lua_tostring(L, -1);
+		lua_pop(L, 1);                 /* ... arr vec */
+	}
+	vec[n + 1] = 0;
+	lua_replace(L, -2);                /* ... vector */
+	return vec;
+}
+
+/* ... argtab */
+void spawn_param_args(struct spawn_params *p)
+{
+	const char **argv = make_vector(p->L);
+	if (!argv[0]) argv[0] = p->command;
+	p->argv = argv;
+}
+
+/* ... envtab/nil */
+void spawn_param_env(struct spawn_params *p)
+{
+	size_t i = 0;
+	luaL_Buffer estr;
+	if (lua_isnil(p->L, -1)) {
+		p->envp = (const char **)environ;
+		return;
+	}
+	luaL_buffinit(p->L, &estr);
+	lua_newtable(p->L);                    /* ... envtab arr */
+	lua_pushnil(p->L);                     /* ... envtab arr nil */
+	for (i = 0; lua_next(p->L, -3); i++) { /* ... envtab arr k v */
+		luaL_prepbuffer(&estr);
+		lua_pushvalue(p->L, -2);           /* ... envtab arr k v k */
+		luaL_addvalue(&estr);
+		luaL_putchar(&estr, '=');
+		lua_pop(p->L, 1);                  /* ... envtab arr k v */
+		luaL_addvalue(&estr);
+		lua_pop(p->L, 1);                  /* ... envtab arr k */
+		luaL_pushresult(&estr);            /* ... envtab arr k estr */
+		lua_rawseti(p->L, -3, i);          /* ... envtab arr[n]=estr k */
+	}                                      /* ... envtab arr */
+	lua_replace(p->L, -2);                 /* ... arr */
+	make_vector(p->L);                     /* ... arr */
+}
+
+/* _ opts ... */
+static int get_redirect(struct spawn_params *p, const char *stdname, int descriptor)
+{
+	int ret;
+	lua_getfield(p->L, 2, stdname);
+	if ((ret = !lua_isnil(p->L, -1)))
+		/* XXX checkuserdata is confusing here */
+		posix_spawn_file_actions_adddup2(&p->file_actions, 
+			fileno(checkuserdata(p->L, -1, LUA_FILEHANDLE)), descriptor);
+	lua_pop(p->L, 1);
+	return ret;
+}
+
+/* _ opts ... */
+void spawn_param_redirects(struct spawn_params *p)
+{
+	posix_spawn_file_actions_init(&p->file_actions);
+	p->has_actions = 1;
+	get_redirect(p, "stdin", STDIN_FILENO);
+	get_redirect(p, "stdout", STDOUT_FILENO);
+	get_redirect(p, "stderr", STDERR_FILENO);
+}
+
+int spawn_param_execute(struct spawn_params *p, struct process *proc)
+{
+	int ret;
+	proc->status = -1;
+	ret = posix_spawnp(&proc->pid, p->command, &p->file_actions, 0, (char *const *)p->argv, (char *const *)p->envp);
+	if (p->has_actions)
+		posix_spawn_file_actions_destroy(&p->file_actions);
+	return ret == 0;
+}
+
+
+/* proc -- exitcode/nil error */
+int process_wait(lua_State *L)
+{
+	struct process *p = checkuserdata(L, 1, PROCESS_HANDLE);
+	if (p->status == -1) {
+		int status;
+		if (-1 == waitpid(p->pid, &status, 0))
+			return push_error(L);
+		p->status = WEXITSTATUS(status);
+	}
+	lua_pushnumber(L, p->status);
+	return 1;
+}
diff --git a/posix/spawn.h b/posix/spawn.h
new file mode 100755
index 0000000..39167de
--- /dev/null
+++ b/posix/spawn.h
@@ -0,0 +1,32 @@
+#ifndef SPAWN_H
+#define SPAWN_H
+
+#ifdef MISSING_POSIX_SPAWN
+#include "posix_spawn.h"
+#endif
+
+#include <lua.h>
+#include <sys/types.h>
+
+#define PROCESS_HANDLE "process"
+struct process {
+	int status;
+	pid_t pid;
+};
+
+struct spawn_params {
+	lua_State *L;
+	const char *command, **argv, **envp;
+	posix_spawn_file_actions_t file_actions;
+	int has_actions;
+};
+
+void spawn_param_filename(struct spawn_params *p);
+void spawn_param_defaults(struct spawn_params *p);
+void spawn_param_args(struct spawn_params *p);
+void spawn_param_env(struct spawn_params *p);
+void spawn_param_redirects(struct spawn_params *p);
+int spawn_param_execute(struct spawn_params *p, struct process *proc);
+int process_wait(lua_State *L);
+
+#endif/*SPAWN_H*/
diff --git a/w32api/Makefile b/w32api/Makefile
index aa65a4b..0ca1e60 100755
--- a/w32api/Makefile
+++ b/w32api/Makefile
@@ -7,5 +7,6 @@ WARNINGS = -W -Wall -Wno-missing-braces
 LUA = /home/mark/src/lang/lua/lua51
 LUALIBS = -L$(LUA)/bin/mingw -llua51
 
-ex.dll: ex.o
-	$(CC) $(TARGET_ARCH) -shared -o $@ ex.o $(LUALIBS) /c/windows/system32/msvcrt.dll
+ex.dll-OBJS = ex.o spawn.o
+ex.dll: $(ex.dll-OBJS)
+	$(CC) $(TARGET_ARCH) -shared -o $@ $(ex.dll-OBJS) $(LUALIBS) /c/windows/system32/msvcrt.dll
diff --git a/w32api/ex.c b/w32api/ex.c
index 14b5dcd..aa6cdc7 100755
--- a/w32api/ex.c
+++ b/w32api/ex.c
@@ -12,15 +12,23 @@
 #include <fcntl.h>
 #include <sys/locking.h>
 
+#include "spawn.h"
+
 
 /* Generally useful function -- what luaL_checkudata() should do */
-static void *luaL_checkuserdata(lua_State *L, int idx, const char *tname)
+extern void *checkuserdata(lua_State *L, int idx, const char *tname)
 {
     void *ud;
     luaL_argcheck(L, ud = luaL_checkudata(L, idx, tname), idx, tname);
     return ud;
 }
 
+/* return HANDLE from a FILE */
+extern HANDLE get_handle(FILE *f)
+{
+	return (HANDLE)_get_osfhandle(fileno(f));
+}
+
 
 /* -- nil error */
 static int push_error(lua_State *L)
@@ -135,11 +143,6 @@ static int ex_currentdir(lua_State *L)
 	return 1;
 }
 
-static HANDLE get_handle(FILE *f)
-{
-	return (HANDLE)_get_osfhandle(fileno(f));
-}
-
 /* pathname -- iter state nil */
 static int ex_dir(lua_State *L) { return luaL_error(L, "not yet implemented"); }
 
@@ -174,7 +177,7 @@ static int file_lock(lua_State *L, FILE *f, const char *mode, long offset, long
 /* file mode [offset [length]] -- true/nil error */
 static int ex_lock(lua_State *L)
 {
-	FILE **pf = luaL_checkuserdata(L, 1, LUA_FILEHANDLE);
+	FILE **pf = checkuserdata(L, 1, LUA_FILEHANDLE);
 	const char *mode = luaL_checkstring(L, 2);
 	long offset = luaL_optnumber(L, 3, 0);
 	long length = luaL_optnumber(L, 4, 0);
@@ -216,146 +219,6 @@ static int ex_pipe(lua_State *L)
 }
 
 
-struct spawn_params {
-	lua_State *L;
-	const char *cmdline;
-	const char *environment;
-	STARTUPINFO si;
-};
-
-static int needs_quoting(const char *s)
-{
-	return s[0] != '"' && strchr(s, ' ');
-}
-
-/* filename ... */
-static void spawn_param_filename(struct spawn_params *p)
-{
-	/* XXX luaL_checkstring is confusing here */
-	p->cmdline = luaL_checkstring(p->L, 1);
-	if (needs_quoting(p->cmdline)) {
-		lua_pushliteral(p->L, "\"");   /* cmd ... q */
-		lua_pushvalue(p->L, 1);        /* cmd ... q cmd */
-		lua_pushvalue(p->L, -2);       /* cmd ... q cmd q */
-		lua_concat(p->L, 3);           /* cmd ... "cmd" */
-		lua_replace(p->L, 1);          /* "cmd" ... */
-		p->cmdline = lua_tostring(p->L, 1);
-	}
-}
-
-/* -- */
-static void spawn_param_defaults(struct spawn_params *p)
-{
-	p->environment = 0;
-	memset(&p->si, 0, sizeof p->si);
-	p->si.cb = sizeof p->si;
-}
-
-/* cmd opts ... argtab -- cmd opts ... cmdline */
-static void spawn_param_args(struct spawn_params *p)
-{
-	lua_State *L = p->L;
-	luaL_Buffer args;
-	luaL_buffinit(L, &args);
-	size_t i, n = lua_objlen(L, -1);
-	/* concatenate the arg array to a string */
-	for (i = 1; i <= n; i++) {
-		int quote;
-		lua_rawgeti(L, -1, i);     /* ... argtab arg */
-		/* XXX checkstring is confusing here */
-		quote = needs_quoting(luaL_checkstring(L, -1));
-		luaL_putchar(&args, ' ');
-		if (quote) luaL_putchar(&args, '"');
-		luaL_addvalue(&args);
-		if (quote) luaL_putchar(&args, '"');
-		lua_pop(L, 1);             /* ... argtab */
-	}
-	luaL_pushresult(&args);        /* ... argtab argstr */
-	lua_pushvalue(L, 1);           /* cmd opts ... argtab argstr cmd */
-	lua_replace(L, -2);            /* cmd opts ... argtab cmd argstr */
-	lua_concat(L, 2);              /* cmd opts ... argtab cmdline */
-	lua_replace(L, -2);            /* cmd opts ... cmdline */
-	p->cmdline = lua_tostring(L, -1);
-}
-
-/* ... envtab */
-static void spawn_param_env(struct spawn_params *p)
-{
-	lua_State *L = p->L;
-	luaL_Buffer env;
-	if (lua_isnil(L, -1)) {
-		p->environment = 0;
-		lua_pop(L, 1);
-		return;
-	}
-	/* convert env table to zstring list */
-	/* {nam1=val1,nam2=val2} => "nam1=val1\0nam2=val2\0\0" */
-	luaL_buffinit(L, &env);
-	lua_pushnil(L);                /* ... envtab nil */
-	while (lua_next(L, -2)) {      /* ... envtab k v */
-		/* XXX luaL_checktype is confusing here */
-		luaL_checktype(L, -2, LUA_TSTRING);
-		luaL_checktype(L, -1, LUA_TSTRING);
-		lua_pushvalue(L, -2);      /* ... envtab k v k */
-		luaL_addvalue(&env);
-		luaL_putchar(&env, '=');
-		lua_pop(L, 1);             /* ... envtab k v */
-		luaL_addvalue(&env);
-		luaL_putchar(&env, '\0');
-		lua_pop(L, 1);             /* ... envtab k */
-	}
-	luaL_putchar(&env, '\0');
-	luaL_pushresult(&env);         /* ... envtab envstr */
-	lua_replace(L, -2);            /* ... envtab envstr */
-	p->environment = lua_tostring(L, -1);
-}
-
-/* _ opts ... */
-static int get_redirect(struct spawn_params *p, const char *stdname, HANDLE *ph)
-{
-	int ret;
-	lua_getfield(p->L, 2, stdname);
-	if ((ret = !lua_isnil(p->L, -1))) {
-		/* XXX checkuserdata is confusing here */
-		FILE **pf = luaL_checkuserdata(p->L, -1, LUA_FILEHANDLE);
-		*ph = get_handle(*pf);
-	}
-	lua_pop(p->L, 1);
-	return ret;
-}
-
-/* _ opts ... */
-static void spawn_param_redirects(struct spawn_params *p)
-{
-	p->si.hStdInput  = GetStdHandle(STD_INPUT_HANDLE);
-	p->si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
-	p->si.hStdError  = GetStdHandle(STD_ERROR_HANDLE);
-	if (get_redirect(p, "stdin",  &p->si.hStdInput)
-		| get_redirect(p, "stdout", &p->si.hStdOutput)
-		| get_redirect(p, "stderr", &p->si.hStdError))
-		p->si.dwFlags = STARTF_USESTDHANDLES;
-}
-
-#define PROCESS_HANDLE "process"
-struct process {
-	int status;
-	HANDLE hProcess;
-};
-
-static int spawn_param_execute(struct spawn_params *p, struct process *proc)
-{
-	char *c = strdup(p->cmdline);
-	char *e = (char *)p->environment; // strdup(p->environment);
-	PROCESS_INFORMATION pi;
-	proc->status = -1;
-	/* XXX does CreateProcess modify its environment argument? */
-	int ret = CreateProcess(0, c, 0, 0, 0, 0, e, 0, &p->si, &pi);
-	if (e) free(e);
-	free(c);
-	if (ret) proc->hProcess = pi.hProcess;
-	return ret;
-}
-
 /* filename [args-opts] -- true/nil,error */
 /* args-opts -- true/nil,error */
 static int ex_spawn(lua_State *L)
@@ -427,20 +290,6 @@ static int ex_spawn(lua_State *L)
 	return 1; /* ... proc */
 }
 
-/* proc -- exitcode/nil error */
-static int process_wait(lua_State *L)
-{
-	struct process *p = luaL_checkuserdata(L, 1, PROCESS_HANDLE);
-	if (p->status == -1) {
-		DWORD exitcode;
-		WaitForSingleObject(p->hProcess, INFINITE);
-		GetExitCodeProcess(p->hProcess, &exitcode);
-		p->status = exitcode;
-	}
-	lua_pushnumber(L, p->status);
-	return 1;
-}
-
 
 static const luaL_reg ex_iolib[] = {
 	{"pipe",  ex_pipe},
diff --git a/w32api/spawn.c b/w32api/spawn.c
new file mode 100755
index 0000000..926a4ce
--- /dev/null
+++ b/w32api/spawn.c
@@ -0,0 +1,153 @@
+#include <stdlib.h>
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+#include <windows.h>
+
+#include "spawn.h"
+
+extern void *checkuserdata(lua_State *L, int index, const char *name);
+extern HANDLE get_handle(FILE *f);
+
+static int needs_quoting(const char *s)
+{
+	return s[0] != '"' && strchr(s, ' ');
+}
+
+/* filename ... */
+void spawn_param_filename(struct spawn_params *p)
+{
+	/* XXX luaL_checkstring is confusing here */
+	p->cmdline = luaL_checkstring(p->L, 1);
+	if (needs_quoting(p->cmdline)) {
+		lua_pushliteral(p->L, "\"");   /* cmd ... q */
+		lua_pushvalue(p->L, 1);        /* cmd ... q cmd */
+		lua_pushvalue(p->L, -2);       /* cmd ... q cmd q */
+		lua_concat(p->L, 3);           /* cmd ... "cmd" */
+		lua_replace(p->L, 1);          /* "cmd" ... */
+		p->cmdline = lua_tostring(p->L, 1);
+	}
+}
+
+/* -- */
+void spawn_param_defaults(struct spawn_params *p)
+{
+	p->environment = 0;
+	memset(&p->si, 0, sizeof p->si);
+	p->si.cb = sizeof p->si;
+}
+
+/* cmd opts ... argtab -- cmd opts ... cmdline */
+void spawn_param_args(struct spawn_params *p)
+{
+	lua_State *L = p->L;
+	luaL_Buffer args;
+	luaL_buffinit(L, &args);
+	size_t i, n = lua_objlen(L, -1);
+	/* concatenate the arg array to a string */
+	for (i = 1; i <= n; i++) {
+		int quote;
+		lua_rawgeti(L, -1, i);     /* ... argtab arg */
+		/* XXX checkstring is confusing here */
+		quote = needs_quoting(luaL_checkstring(L, -1));
+		luaL_putchar(&args, ' ');
+		if (quote) luaL_putchar(&args, '"');
+		luaL_addvalue(&args);
+		if (quote) luaL_putchar(&args, '"');
+		lua_pop(L, 1);             /* ... argtab */
+	}
+	luaL_pushresult(&args);        /* ... argtab argstr */
+	lua_pushvalue(L, 1);           /* cmd opts ... argtab argstr cmd */
+	lua_replace(L, -2);            /* cmd opts ... argtab cmd argstr */
+	lua_concat(L, 2);              /* cmd opts ... argtab cmdline */
+	lua_replace(L, -2);            /* cmd opts ... cmdline */
+	p->cmdline = lua_tostring(L, -1);
+}
+
+/* ... envtab */
+void spawn_param_env(struct spawn_params *p)
+{
+	lua_State *L = p->L;
+	luaL_Buffer env;
+	if (lua_isnil(L, -1)) {
+		p->environment = 0;
+		lua_pop(L, 1);
+		return;
+	}
+	/* convert env table to zstring list */
+	/* {nam1=val1,nam2=val2} => "nam1=val1\0nam2=val2\0\0" */
+	luaL_buffinit(L, &env);
+	lua_pushnil(L);                /* ... envtab nil */
+	while (lua_next(L, -2)) {      /* ... envtab k v */
+		/* XXX luaL_checktype is confusing here */
+		luaL_checktype(L, -2, LUA_TSTRING);
+		luaL_checktype(L, -1, LUA_TSTRING);
+		lua_pushvalue(L, -2);      /* ... envtab k v k */
+		luaL_addvalue(&env);
+		luaL_putchar(&env, '=');
+		lua_pop(L, 1);             /* ... envtab k v */
+		luaL_addvalue(&env);
+		luaL_putchar(&env, '\0');
+		lua_pop(L, 1);             /* ... envtab k */
+	}
+	luaL_putchar(&env, '\0');
+	luaL_pushresult(&env);         /* ... envtab envstr */
+	lua_replace(L, -2);            /* ... envtab envstr */
+	p->environment = lua_tostring(L, -1);
+}
+
+/* _ opts ... */
+static int get_redirect(struct spawn_params *p, const char *stdname, HANDLE *ph)
+{
+	int ret;
+	lua_getfield(p->L, 2, stdname);
+	if ((ret = !lua_isnil(p->L, -1))) {
+		/* XXX checkuserdata is confusing here */
+		FILE **pf = checkuserdata(p->L, -1, LUA_FILEHANDLE);
+		*ph = get_handle(*pf);
+	}
+	lua_pop(p->L, 1);
+	return ret;
+}
+
+/* _ opts ... */
+void spawn_param_redirects(struct spawn_params *p)
+{
+	p->si.hStdInput  = GetStdHandle(STD_INPUT_HANDLE);
+	p->si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
+	p->si.hStdError  = GetStdHandle(STD_ERROR_HANDLE);
+	if (get_redirect(p, "stdin",  &p->si.hStdInput)
+		| get_redirect(p, "stdout", &p->si.hStdOutput)
+		| get_redirect(p, "stderr", &p->si.hStdError))
+		p->si.dwFlags = STARTF_USESTDHANDLES;
+}
+
+int spawn_param_execute(struct spawn_params *p, struct process *proc)
+{
+	char *c = strdup(p->cmdline);
+	char *e = (char *)p->environment; // strdup(p->environment);
+	PROCESS_INFORMATION pi;
+	proc->status = -1;
+	/* XXX does CreateProcess modify its environment argument? */
+	int ret = CreateProcess(0, c, 0, 0, 0, 0, e, 0, &p->si, &pi);
+	if (e) free(e);
+	free(c);
+	if (ret) proc->hProcess = pi.hProcess;
+	return ret;
+}
+
+/* proc -- exitcode/nil error */
+int process_wait(lua_State *L)
+{
+	struct process *p = checkuserdata(L, 1, PROCESS_HANDLE);
+	if (p->status == -1) {
+		DWORD exitcode;
+		WaitForSingleObject(p->hProcess, INFINITE);
+		GetExitCodeProcess(p->hProcess, &exitcode);
+		p->status = exitcode;
+	}
+	lua_pushnumber(L, p->status);
+	return 1;
+}
diff --git a/w32api/spawn.h b/w32api/spawn.h
new file mode 100755
index 0000000..1d91235
--- /dev/null
+++ b/w32api/spawn.h
@@ -0,0 +1,29 @@
+#ifndef SPAWN_H
+#define SPAWN_H
+#include <lua.h>
+
+#include <windows.h>
+
+struct spawn_params {
+	lua_State *L;
+	const char *cmdline;
+	const char *environment;
+	STARTUPINFO si;
+};
+
+#define PROCESS_HANDLE "process"
+struct process {
+    int status;
+    HANDLE hProcess;
+};
+
+void spawn_param_filename(struct spawn_params *p);
+void spawn_param_defaults(struct spawn_params *p);
+void spawn_param_args(struct spawn_params *p);
+void spawn_param_env(struct spawn_params *p);
+void spawn_param_redirects(struct spawn_params *p);
+int spawn_param_execute(struct spawn_params *p, struct process *proc);
+
+int process_wait(lua_State *L);
+
+#endif/*SPAWN_H*/