new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_files.c
@@ -0,0 +1,268 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+ssize_t ngx_read_file(ngx_file_t *file, u_char *buf, size_t size, off_t offset)
+{
+    ssize_t n;
+
+    ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0,
+                   "read: %d, %X, %d, " OFF_T_FMT, file->fd, buf, size, offset);
+
+#if (HAVE_PREAD)
+
+    n = pread(file->fd, buf, size, offset);
+
+    if (n == -1) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno,
+                      "pread() failed, file \"%s\"", file->name.data);
+        return NGX_ERROR;
+    }
+
+#else
+
+    if (file->sys_offset != offset) {
+        if (lseek(file->fd, offset, SEEK_SET) == -1) {
+            ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "lseek() failed");
+            return NGX_ERROR;
+        }
+
+        file->sys_offset = offset;
+    }
+
+    n = read(file->fd, buf, size);
+
+    if (n == -1) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "read() failed");
+        return NGX_ERROR;
+    }
+
+    file->sys_offset += n;
+
+#endif
+
+    file->offset += n;
+
+    return n;
+}
+
+
+ssize_t ngx_write_file(ngx_file_t *file, u_char *buf, size_t size, off_t offset)
+{
+    ssize_t n;
+
+#if (HAVE_PWRITE)
+
+    n = pwrite(file->fd, buf, size, offset);
+
+    if (n == -1) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "pwrite() failed");
+        return NGX_ERROR;
+    }
+
+    if ((size_t) n != size) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, 0,
+                      "pwrite() has written only %d of %d", n, size);
+        return NGX_ERROR;
+    }
+
+#else
+
+    if (file->sys_offset != offset) {
+        if (lseek(file->fd, offset, SEEK_SET) == -1) {
+            ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "lseek() failed");
+            return NGX_ERROR;
+        }
+
+        file->sys_offset = offset;
+    }
+
+    n = write(file->fd, buf, size);
+
+    if (n == -1) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "write() failed");
+        return NGX_ERROR;
+    }
+
+    if ((size_t) n != size) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, 0,
+                      "write() has written only %d of %d", n, size);
+        return NGX_ERROR;
+    }
+
+    file->sys_offset += n;
+
+#endif
+
+    file->offset += n;
+
+    return n;
+}
+
+
+int ngx_open_tempfile(u_char *name, ngx_uint_t persistent)
+{
+    ngx_fd_t  fd;
+
+    fd = open((const char *) name, O_CREAT|O_EXCL|O_RDWR, 0600);
+
+    if (fd != -1 && !persistent) {
+        unlink((const char *) name);
+    }
+
+    return fd;
+}
+
+
+ssize_t ngx_write_chain_to_file(ngx_file_t *file, ngx_chain_t *cl,
+                                off_t offset, ngx_pool_t *pool)
+{
+    u_char        *prev;
+    size_t         size;
+    ssize_t        n;
+    struct iovec  *iov;
+    ngx_err_t      err;
+    ngx_array_t    io;
+
+    /* use pwrite() if there's the only buf in a chain */
+
+    if (cl->next == NULL) {
+        return ngx_write_file(file, cl->buf->pos,
+                              (size_t) (cl->buf->last - cl->buf->pos),
+                              offset);
+    }
+
+    prev = NULL;
+    iov = NULL;
+    size = 0;
+
+    ngx_init_array(io, pool, 10, sizeof(struct iovec), NGX_ERROR);
+
+    /* create the iovec and coalesce the neighbouring bufs */
+
+    while (cl) {
+        if (prev == cl->buf->pos) {
+            iov->iov_len += cl->buf->last - cl->buf->pos;
+
+        } else {
+            ngx_test_null(iov, ngx_push_array(&io), NGX_ERROR);
+            iov->iov_base = (void *) cl->buf->pos;
+            iov->iov_len = cl->buf->last - cl->buf->pos;
+        }
+
+        size += cl->buf->last - cl->buf->pos;
+        prev = cl->buf->last;
+        cl = cl->next;
+    }
+
+    /* use pwrite() if there's the only iovec buffer */
+
+    if (io.nelts == 1) {
+        iov = io.elts;
+        return ngx_write_file(file, (u_char *) iov[0].iov_base, iov[0].iov_len,
+                              offset);
+    }
+
+    if (file->sys_offset != offset) {
+        if (lseek(file->fd, offset, SEEK_SET) == -1) {
+            ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "lseek() failed");
+            return NGX_ERROR;
+        }
+
+        file->sys_offset = offset;
+    }
+
+    n = writev(file->fd, io.elts, io.nelts);
+
+    if (n == -1) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, "writev() failed");
+        return NGX_ERROR;
+    }
+
+    if ((size_t) n != size) {
+        ngx_log_error(NGX_LOG_CRIT, file->log, 0,
+                      "writev() has written only %d of %d", n, size);
+        return NGX_ERROR;
+    }
+
+    file->sys_offset += n;
+    file->offset += n;
+
+    return n;
+}
+
+
+int ngx_open_dir(ngx_str_t *name, ngx_dir_t *dir)
+{
+    dir->dir = opendir((const char *) name->data);
+
+    if (dir->dir == NULL) {
+        return NGX_ERROR;
+    }
+
+    dir->info_valid = 0;
+
+    return NGX_OK;
+}
+
+
+#if 0
+
+ssize_t ngx_read_file(ngx_file_t *file, char *buf, size_t size, off_t offset)
+{
+    if (!file->read->ready) {
+
+        ngx_memzero(&file->iocb, sizeof(iocb));
+        file->iocb.aio_fildes = file->fd;
+        file->iocb.aio_buf = buf;
+        file->iocb.aio_nbytes = size;
+        file->iocb.aio_offset = offset;
+#if (USE_AIO_KQUEUE)
+        file->iocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
+        file->iocb.aio_sigevent.sigev_notify_kqueue = tid->kq;
+        file->iocb.aio_sigevent.sigev_value = (union sigval) file;
+#endif
+#if (USE_AIO_SIGNAL)
+        file->iocb.aio_sigevent.sigev_notify = SIGEV_SIGNAL;
+        file->iocb.aio_sigevent.sigev_signo = NGX_SIGAIO;
+#ifndef __FreeBSD__
+        file->iocb.aio_sigevent.sigev_value.sival_ptr = file;
+#endif
+#endif
+
+        if (aio_read(&file->iocb) == -1) {
+            ngx_log_error(NGX_LOG_ERR, file->log, ngx_errno,
+                          "aio_read() failed");
+            return NGX_ERROR;
+
+        n = aio_error(&file->iocb);
+        if (n == EINPROGRESS)
+            return NGX_AGAIN;
+
+        if (n == -1) {
+            ngx_log_error(NGX_LOG_ERR, file->log, ngx_errno,
+                          "aio_read() failed");
+            return NGX_ERROR;
+        }
+    }
+
+    ngx_assert(file->iocb.aio_buf == buf), return NGX_ERROR,
+               "ngx_aio_read_file: another buffer is passed");
+
+    n = aio_return(&file->iocb);
+    if (n == -1) {
+        ngx_log_error(NGX_LOG_ERR, file->log, ngx_errno,
+                      "aio_read() failed");
+        return NGX_ERROR;
+    }
+
+    return n;
+}
+
+#endif