new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_errno.h
@@ -0,0 +1,60 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_ERRNO_H_INCLUDED_
+#define _NGX_ERRNO_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+typedef int               ngx_err_t;
+
+#define NGX_ENOENT        ENOENT
+#define NGX_ESRCH         ESRCH
+#define NGX_EINTR         EINTR
+#define NGX_ECHILD        ECHILD
+#define NGX_ENOMEM        ENOMEM
+#define NGX_EACCES        EACCES
+#define NGX_EBUSY         EBUSY
+#define NGX_EEXIST        EEXIST
+#define NGX_ENOTDIR       ENOTDIR
+#define NGX_EINVAL        EINVAL
+#define NGX_EPIPE         EPIPE
+#define NGX_EAGAIN        EWOULDBLOCK
+#define NGX_EINPROGRESS   EINPROGRESS
+#define NGX_EADDRINUSE    EADDRINUSE
+#define NGX_ECONNABORTED  ECONNABORTED
+#define NGX_ECONNRESET    ECONNRESET
+#define NGX_ENOTCONN      ENOTCONN
+#define NGX_ETIMEDOUT     ETIMEDOUT
+#define NGX_ECONNREFUSED  ECONNREFUSED
+#define NGX_EHOSTUNREACH  EHOSTUNREACH
+#define NGX_ECANCELED     ECANCELED
+#define NGX_ENOMOREFILES  0
+
+
+
+#define ngx_errno                  errno
+#define ngx_socket_errno           errno
+#define ngx_set_errno(err)         errno = err
+#define ngx_set_socket_errno(err)  errno = err
+
+
+#if (HAVE_STRERROR_R || HAVE_GNU_STRERROR_R)
+
+ngx_int_t ngx_strerror_r(int err, char *errstr, size_t size);
+
+#else
+
+#define ngx_strerror_r(err, errstr, size)  \
+             (char *) ngx_cpystrn(errstr, strerror(err), size) - (errstr)
+
+#endif
+
+
+#endif /* _NGX_ERRNO_H_INCLUDED_ */