diff --git a/src/os_unix.h b/src/os_unix.h
new file mode 100644
index 0000000..b78b23e
--- /dev/null
+++ b/src/os_unix.h
@@ -0,0 +1,531 @@
+/* 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.
+ */
+
+/*
+ * NextStep has a problem with configure, undefine a few things:
+ */
+#ifdef NeXT
+# ifdef HAVE_UTIME
+#  undef HAVE_UTIME
+# endif
+# ifdef HAVE_SYS_UTSNAME_H
+#  undef HAVE_SYS_UTSNAME_H
+# endif
+#endif
+
+#include <stdio.h>
+#include <ctype.h>
+
+#ifdef VAXC
+# include <types.h>
+# include <stat.h>
+#else
+# include <sys/types.h>
+# include <sys/stat.h>
+#endif
+
+#ifdef HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+
+#ifdef __EMX__
+# define HAVE_TOTAL_MEM
+#endif
+
+#if defined(__CYGWIN__) || defined(__CYGWIN32__)
+# define WIN32UNIX	/* Compiling for Win32 using Unix files. */
+# define BINARY_FILE_IO
+#endif
+
+/* On AIX 4.2 there is a conflicting prototype for ioctl() in stropts.h and
+ * unistd.h.  This hack should fix that (suggested by Jeff George).
+ * But on AIX 4.3 it's alright (suggested by Jake Hamby). */
+#if defined(FEAT_GUI) && defined(_AIX) && !defined(_AIX43) && !defined(_NO_PROTO)
+# define _NO_PROTO
+#endif
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#ifdef HAVE_LIBC_H
+# include <libc.h>		    /* for NeXT */
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+# include <sys/param.h>	    /* defines BSD, if it's a BSD system */
+#endif
+
+/*
+ * Sun defines FILE on SunOS 4.x.x, Solaris has a typedef for FILE
+ */
+#if defined(sun) && !defined(FILE)
+# define SOLARIS
+#endif
+
+/*
+ * Using getcwd() is preferred, because it checks for a buffer overflow.
+ * Don't use getcwd() on systems do use system("sh -c pwd").  There is an
+ * autoconf check for this.
+ * Use getcwd() anyway if getwd() isn't present.
+ */
+#if defined(HAVE_GETCWD) && !(defined(BAD_GETCWD) && defined(HAVE_GETWD))
+# define USE_GETCWD
+#endif
+
+#ifndef __ARGS
+    /* The AIX VisualAge cc compiler defines __EXTENDED__ instead of __STDC__
+     * because it includes pre-ansi features. */
+# if defined(__STDC__) || defined(__GNUC__) || defined(__EXTENDED__)
+#  define __ARGS(x) x
+# else
+#  define __ARGS(x) ()
+# endif
+#endif
+
+/* always use unlink() to remove files */
+#ifndef PROTO
+# ifdef VMS
+#  define mch_remove(x) delete((char *)(x))
+#  define vim_mkdir(x, y) mkdir((char *)(x), y)
+#  ifdef VAX
+#  else
+#   define mch_rmdir(x) rmdir((char *)(x))
+#  endif
+# else
+#  define vim_mkdir(x, y) mkdir((char *)(x), y)
+#  define mch_rmdir(x) rmdir((char *)(x))
+#  define mch_remove(x) unlink((char *)(x))
+# endif
+#endif
+
+/* The number of arguments to a signal handler is configured here. */
+/* It used to be a long list of almost all systems. Any system that doesn't
+ * have an argument??? */
+#define SIGHASARG
+
+/* List 3 arg systems here. I guess __sgi, please test and correct me. jw. */
+#if defined(__sgi) && defined(HAVE_SIGCONTEXT)
+# define SIGHAS3ARGS
+#endif
+
+#ifdef SIGHASARG
+# ifdef SIGHAS3ARGS
+#  define SIGPROTOARG	(int, int, struct sigcontext *)
+#  define SIGDEFARG(s)	(s, sig2, scont) int s, sig2; struct sigcontext *scont;
+#  define SIGDUMMYARG	0, 0, (struct sigcontext *)0
+# else
+#  define SIGPROTOARG	(int)
+#  define SIGDEFARG(s)	(s) int s;
+#  define SIGDUMMYARG	0
+# endif
+#else
+# define SIGPROTOARG   (void)
+# define SIGDEFARG(s)  ()
+# define SIGDUMMYARG
+#endif
+
+#ifdef HAVE_DIRENT_H
+# include <dirent.h>
+# ifndef NAMLEN
+#  define NAMLEN(dirent) strlen((dirent)->d_name)
+# endif
+#else
+# define dirent direct
+# define NAMLEN(dirent) (dirent)->d_namlen
+# if HAVE_SYS_NDIR_H
+#  include <sys/ndir.h>
+# endif
+# if HAVE_SYS_DIR_H
+#  include <sys/dir.h>
+# endif
+# if HAVE_NDIR_H
+#  include <ndir.h>
+# endif
+#endif
+
+#if !defined(HAVE_SYS_TIME_H) || defined(TIME_WITH_SYS_TIME)
+# include <time.h>	    /* on some systems time.h should not be
+			       included together with sys/time.h */
+#endif
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+#include <signal.h>
+
+#if defined(DIRSIZ) && !defined(MAXNAMLEN)
+# define MAXNAMLEN DIRSIZ
+#endif
+
+#if defined(UFS_MAXNAMLEN) && !defined(MAXNAMLEN)
+# define MAXNAMLEN UFS_MAXNAMLEN    /* for dynix/ptx */
+#endif
+
+#if defined(NAME_MAX) && !defined(MAXNAMLEN)
+# define MAXNAMLEN NAME_MAX	    /* for Linux before .99p3 */
+#endif
+
+/*
+ * Note: if MAXNAMLEN has the wrong value, you will get error messages
+ *	 for not being able to open the swap file.
+ */
+#if !defined(MAXNAMLEN)
+# define MAXNAMLEN 512		    /* for all other Unix */
+#endif
+
+#define BASENAMELEN	(MAXNAMLEN - 5)
+
+#ifdef HAVE_ERRNO_H
+# include <errno.h>
+#endif
+
+#ifdef HAVE_PWD_H
+# include <pwd.h>
+#endif
+
+#ifdef __COHERENT__
+# undef __ARGS
+#endif
+
+#if (defined(HAVE_SYS_RESOURCE_H) && defined(HAVE_GETRLIMIT)) \
+	|| (defined(HAVE_SYS_SYSINFO_H) && defined(HAVE_SYSINFO)) \
+	|| defined(HAVE_SYSCTL) || defined(HAVE_SYSCONF)
+# define HAVE_TOTAL_MEM
+#endif
+
+#ifdef VMS
+#include <unixio.h>
+#include <unixlib.h>
+#include <signal.h>
+#include <file.h>
+#include <ssdef.h>
+#include <descrip.h>
+#include <libclidef.h>
+#include <lnmdef.h>
+#include <psldef.h>
+#include <prvdef.h>
+#include <dvidef.h>
+#include <dcdef.h>
+#include <stsdef.h>
+#include <iodef.h>
+#include <ttdef.h>
+#include <tt2def.h>
+#include <jpidef.h>
+#include <rms.h>
+#include <trmdef.h>
+#include <string.h>
+#include <starlet.h>
+#include <socket.h>
+#include <lib$routines.h>
+
+typedef struct dsc$descriptor   DESC;
+#endif
+
+/*
+ * Unix system-dependent file names
+ */
+#ifndef SYS_VIMRC_FILE
+# define SYS_VIMRC_FILE "$VIM/vimrc"
+#endif
+#ifndef SYS_GVIMRC_FILE
+# define SYS_GVIMRC_FILE "$VIM/gvimrc"
+#endif
+#ifndef DFLT_HELPFILE
+# define DFLT_HELPFILE	"$VIMRUNTIME/doc/help.txt"
+#endif
+#ifndef FILETYPE_FILE
+# define FILETYPE_FILE	"filetype.vim"
+#endif
+#ifndef FTPLUGIN_FILE
+# define FTPLUGIN_FILE	"ftplugin.vim"
+#endif
+#ifndef INDENT_FILE
+# define INDENT_FILE	"indent.vim"
+#endif
+#ifndef FTOFF_FILE
+# define FTOFF_FILE	"ftoff.vim"
+#endif
+#ifndef FTPLUGOF_FILE
+# define FTPLUGOF_FILE	"ftplugof.vim"
+#endif
+#ifndef INDOFF_FILE
+# define INDOFF_FILE	"indoff.vim"
+#endif
+#ifndef SYS_MENU_FILE
+# define SYS_MENU_FILE	"$VIMRUNTIME/menu.vim"
+#endif
+
+#ifndef USR_EXRC_FILE
+# ifdef VMS
+#  define USR_EXRC_FILE "sys$login:.exrc"
+# else
+#  define USR_EXRC_FILE "$HOME/.exrc"
+# endif
+#endif
+
+#if !defined(USR_EXRC_FILE2) && defined(OS2)
+# define USR_EXRC_FILE2 "$VIM/.exrc"
+#endif
+#if !defined(USR_EXRC_FILE2) && defined(VMS)
+# define USR_EXRC_FILE2 "sys$login:_exrc"
+#endif
+
+#ifndef USR_VIMRC_FILE
+# ifdef VMS
+# define USR_VIMRC_FILE  "sys$login:.vimrc"
+# else
+#  define USR_VIMRC_FILE "$HOME/.vimrc"
+# endif
+#endif
+
+#if !defined(USR_VIMRC_FILE2) && defined(OS2)
+# define USR_VIMRC_FILE2 "$VIM/.vimrc"
+#endif
+#if !defined(USR_VIMRC_FILE2) && defined(VMS)
+# define USR_VIMRC_FILE2 "sys$login:_vimrc"
+#endif
+
+#ifndef USR_GVIMRC_FILE
+# ifdef VMS
+#  define USR_GVIMRC_FILE "sys$login:.gvimrc"
+# else
+#  define USR_GVIMRC_FILE "$HOME/.gvimrc"
+# endif
+#endif
+
+#ifdef VMS
+# ifndef USR_GVIMRC_FILE2
+#  define USR_GVIMRC_FILE2  "sys$login:_gvimrc"
+# endif
+#endif
+
+#ifndef EVIM_FILE
+# define EVIM_FILE	"$VIMRUNTIME/evim.vim"
+#endif
+
+#ifdef FEAT_VIMINFO
+# ifndef VIMINFO_FILE
+#  ifdef VMS
+#   define VIMINFO_FILE  "sys$login:.viminfo"
+#  else
+#   define VIMINFO_FILE "$HOME/.viminfo"
+#  endif
+# endif
+# if !defined(VIMINFO_FILE2) && defined(OS2)
+#  define VIMINFO_FILE2 "$VIM/.viminfo"
+# endif
+# if !defined(VIMINFO_FILE2) && defined(VMS)
+#  define VIMINFO_FILE2 "sys$login:_viminfo"
+# endif
+#endif
+
+#ifndef EXRC_FILE
+# define EXRC_FILE	".exrc"
+#endif
+
+#ifndef VIMRC_FILE
+# define VIMRC_FILE	".vimrc"
+#endif
+
+#ifdef FEAT_GUI
+# ifndef GVIMRC_FILE
+#  define GVIMRC_FILE	".gvimrc"
+# endif
+#endif
+
+#ifndef SYNTAX_FNAME
+# define SYNTAX_FNAME	"$VIMRUNTIME/syntax/%s.vim"
+#endif
+
+#ifndef DFLT_BDIR
+# ifdef OS2
+#  define DFLT_BDIR     ".,c:/tmp,~/tmp,~/"
+# else
+#  ifdef VMS
+#   define DFLT_BDIR    "./,sys$login:,tmp:"
+#  else
+#   define DFLT_BDIR    ".,~/tmp,~/"    /* default for 'backupdir' */
+#  endif
+# endif
+#endif
+
+#ifndef DFLT_DIR
+# ifdef OS2
+#  define DFLT_DIR      ".,~/tmp,c:/tmp,/tmp"
+# else
+#  ifdef VMS
+#   define DFLT_DIR     "./,sys$login:,tmp:"
+#  else
+#   define DFLT_DIR     ".,~/tmp,/var/tmp,/tmp" /* default for 'directory' */
+#  endif
+# endif
+#endif
+
+#ifndef DFLT_VDIR
+# ifdef OS2
+#  define DFLT_VDIR     "$VIM/vimfiles/view"
+# else
+#  ifdef VMS
+#   define DFLT_VDIR    "sys$login:vimfiles/view"
+#  else
+#   define DFLT_VDIR    "$HOME/.vim/view"       /* default for 'viewdir' */
+#  endif
+# endif
+#endif
+
+#define DFLT_ERRORFILE		"errors.err"
+
+#ifdef OS2
+# define DFLT_RUNTIMEPATH	"$HOME/vimfiles,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,$HOME/vimfiles/after"
+#else
+# ifdef VMS
+#  define DFLT_RUNTIMEPATH      "sys$login:vimfiles,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,sys$login:vimfiles/after"
+# else
+#  ifdef RUNTIME_GLOBAL
+#   define DFLT_RUNTIMEPATH	"~/.vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL "/after,~/.vim/after"
+#  else
+#   define DFLT_RUNTIMEPATH	"~/.vim,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,~/.vim/after"
+#  endif
+# endif
+#endif
+
+#ifdef OS2
+/*
+ * Try several directories to put the temp files.
+ */
+# define TEMPDIRNAMES	"$TMP", "$TEMP", "c:\\TMP", "c:\\TEMP", ""
+# define TEMPNAMELEN	128
+#else
+# ifdef VMS
+#  ifndef VAX
+#   define VMS_TEMPNAM    /* to fix default .LIS extension */
+#  endif
+#  define TEMPNAME       "TMP:v?XXXXXX.txt"
+#  define TEMPNAMELEN    28
+# else
+#  define TEMPDIRNAMES  "$TMPDIR", "/tmp", ".", "$HOME"
+#  define TEMPNAMELEN    256
+# endif
+#endif
+
+/* Special wildcards that need to be handled by the shell */
+#define SPECIAL_WILDCHAR    "`'{"
+
+#ifndef HAVE_OPENDIR
+# define NO_EXPANDPATH
+#endif
+
+/*
+ * Unix has plenty of memory, use large buffers
+ */
+#define CMDBUFFSIZE 1024	/* size of the command processing buffer */
+#define MAXPATHL    1024	/* Unix has long paths and plenty of memory */
+
+#define CHECK_INODE		/* used when checking if a swap file already
+				    exists for a file */
+#ifdef VMS  /* Use less memory because of older systems  */
+# ifndef DFLT_MAXMEM
+#  define DFLT_MAXMEM (2*1024)
+# endif
+# ifndef DFLT_MAXMEMTOT
+#  define DFLT_MAXMEMTOT (5*1024)
+# endif
+#else
+# ifndef DFLT_MAXMEM
+#  define DFLT_MAXMEM	(5*1024)	 /* use up to 5 Mbyte for a buffer */
+# endif
+# ifndef DFLT_MAXMEMTOT
+#  define DFLT_MAXMEMTOT	(10*1024)    /* use up to 10 Mbyte for Vim */
+# endif
+#endif
+
+/* memmove is not present on all systems, use memmove, bcopy, memcpy or our
+ * own version */
+/* Some systems have (void *) arguments, some (char *). If we use (char *) it
+ * works for all */
+#ifdef USEMEMMOVE
+# define mch_memmove(to, from, len) memmove((char *)(to), (char *)(from), len)
+#else
+# ifdef USEBCOPY
+#  define mch_memmove(to, from, len) bcopy((char *)(from), (char *)(to), len)
+# else
+#  ifdef USEMEMCPY
+#   define mch_memmove(to, from, len) memcpy((char *)(to), (char *)(from), len)
+#  else
+#   define VIM_MEMMOVE	    /* found in misc2.c */
+#  endif
+# endif
+#endif
+
+#ifndef PROTO
+# ifdef HAVE_RENAME
+#  define mch_rename(src, dst) rename(src, dst)
+# else
+int mch_rename __ARGS((const char *src, const char *dest));
+# endif
+# ifdef VMS
+#  define mch_chdir(s) chdir(vms_fixfilename(s))
+# else
+#  define mch_chdir(s) chdir(s)
+# endif
+# ifndef VMS
+#  ifdef __MVS__
+  /* on OS390 Unix getenv() doesn't return a pointer to persistant
+   * storage -> use __getenv() */
+#   define mch_getenv(x) (char_u *)__getenv((char *)(x))
+#  else
+#   define mch_getenv(x) (char_u *)getenv((char *)(x))
+#  endif
+#  define mch_setenv(name, val, x) setenv(name, val, x)
+# endif
+#endif
+
+#if !defined(S_ISDIR) && defined(S_IFDIR)
+# define	S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+#endif
+#if !defined(S_ISREG) && defined(S_IFREG)
+# define	S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
+#endif
+#if !defined(S_ISBLK) && defined(S_IFBLK)
+# define	S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
+#endif
+#if !defined(S_ISSOCK) && defined(S_IFSOCK)
+# define	S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
+#endif
+#if !defined(S_ISFIFO) && defined(S_IFIFO)
+# define	S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
+#endif
+
+/* Note: Some systems need both string.h and strings.h (Savage).  However,
+ * some systems can't handle both, only use string.h in that case. */
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif
+#if defined(HAVE_STRINGS_H) && !defined(NO_STRINGS_WITH_STRING_H)
+# include <strings.h>
+#endif
+
+#if defined(HAVE_SETJMP_H)
+# include <setjmp.h>
+# ifdef HAVE_SIGSETJMP
+#  define JMP_BUF sigjmp_buf
+#  define SETJMP(x) sigsetjmp((x), 1)
+#  define LONGJMP siglongjmp
+# else
+#  define JMP_BUF jmp_buf
+#  define SETJMP(x) setjmp(x)
+#  define LONGJMP longjmp
+# endif
+#endif
+
+#define HAVE_DUP		/* have dup() */
+#define HAVE_ST_MODE		/* have stat.st_mode */
+
+/* We have three kinds of ACL support. */
+#define HAVE_ACL (HAVE_POSIX_ACL || HAVE_SOLARIS_ACL || HAVE_AIX_ACL)