diff --git a/src/os_unixx.h b/src/os_unixx.h
new file mode 100644
index 0000000..9f4f7eb
--- /dev/null
+++ b/src/os_unixx.h
@@ -0,0 +1,130 @@
+/* vi:set ts=8 sts=4 sw=4:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ */
+
+/*
+ * os_unixx.h -- include files that are only used in os_unix.c
+ */
+
+/*
+ * Stuff for signals
+ */
+#if defined(HAVE_SIGSET) && !defined(signal)
+# define signal sigset
+#endif
+
+   /* sun's sys/ioctl.h redefines symbols from termio world */
+#if defined(HAVE_SYS_IOCTL_H) && !defined(sun)
+# include <sys/ioctl.h>
+#endif
+
+#ifndef USE_SYSTEM	/* use fork/exec to start the shell */
+
+# if defined(HAVE_SYS_WAIT_H) || defined(HAVE_UNION_WAIT)
+#  include <sys/wait.h>
+# endif
+
+# if defined(HAVE_SYS_SELECT_H) && \
+	(!defined(HAVE_SYS_TIME_H) || defined(SYS_SELECT_WITH_SYS_TIME))
+#  include <sys/select.h>
+# endif
+
+# ifndef WEXITSTATUS
+#  ifdef HAVE_UNION_WAIT
+#   define WEXITSTATUS(stat_val) ((stat_val).w_T.w_Retcode)
+#  else
+#   define WEXITSTATUS(stat_val) (((stat_val) >> 8) & 0377)
+#  endif
+# endif
+
+# ifndef WIFEXITED
+#  ifdef HAVE_UNION_WAIT
+#   define WIFEXITED(stat_val) ((stat_val).w_T.w_Termsig == 0)
+#  else
+#   define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#  endif
+# endif
+
+#endif /* !USE_SYSTEM */
+
+#ifdef HAVE_STROPTS_H
+#ifdef sinix
+#define buf_T __system_buf_t__
+#endif
+# include <stropts.h>
+#ifdef sinix
+#undef buf_T
+#endif
+#endif
+
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif
+
+#ifndef HAVE_SELECT
+# ifdef HAVE_SYS_POLL_H
+#  include <sys/poll.h>
+# else
+#  ifdef HAVE_POLL_H
+#   include <poll.h>
+#  endif
+# endif
+#endif
+
+#ifdef HAVE_SYS_STREAM_H
+# include <sys/stream.h>
+#endif
+
+#ifdef HAVE_SYS_UTSNAME_H
+# include <sys/utsname.h>
+#endif
+
+#ifdef HAVE_SYS_SYSTEMINFO_H
+/*
+ * foolish Sinix <sys/systeminfo.h> uses SYS_NMLN but doesn't include
+ * <limits.h>, where it is defined. Perhaps other systems have the same
+ * problem? Include it here. -- Slootman
+ */
+# if defined(HAVE_LIMITS_H) && !defined(_LIMITS_H)
+#  include <limits.h>		/* for SYS_NMLN (Sinix 5.41 / Unix SysV.4) */
+# endif
+# include <sys/systeminfo.h>	/* for sysinfo */
+#endif
+
+/*
+ * We use termios.h if both termios.h and termio.h are available.
+ * Termios is supposed to be a superset of termio.h.  Don't include them both,
+ * it may give problems on some systems (e.g. hpux).
+ * I don't understand why we don't want termios.h for apollo.
+ */
+#if defined(HAVE_TERMIOS_H) && !defined(apollo)
+#  include <termios.h>
+#else
+# ifdef HAVE_TERMIO_H
+#  include <termio.h>
+# else
+#  ifdef HAVE_SGTTY_H
+#   include <sgtty.h>
+#  endif
+# endif
+#endif
+
+#ifdef HAVE_SYS_PTEM_H
+# include <sys/ptem.h>	/* must be after termios.h for Sinix */
+# ifndef _IO_PTEM_H	/* For UnixWare that should check for _IO_PT_PTEM_H */
+#  define _IO_PTEM_H
+# endif
+#endif
+
+/* shared library access */
+#if defined(HAVE_DLFCN_H) && defined(USE_DLOPEN)
+# include <dlfcn.h>
+#else
+# if defined(HAVE_DL_H) && defined(HAVE_SHL_LOAD)
+#  include <dl.h>
+# endif
+#endif