new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_daemon.c
@@ -0,0 +1,80 @@
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_log.h>
+
+/* daemon in Linux */
+
+int ngx_daemon(ngx_log_t *log)
+{
+    int  fd;
+
+    switch (fork()) {
+    case -1:
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "fork() failed");
+        return NGX_ERROR;
+
+    case 0:
+        break;
+
+    default:
+        exit(0);
+    }
+
+    if (setsid() == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "setsid() failed");
+        return NGX_ERROR;
+    }
+
+#if (__SVR4 || linux)
+
+    /* need HUP IGN ? check in Solaris and Linux */
+
+    switch (fork()) {
+    case -1:
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "fork() failed");
+        return NGX_ERROR;
+
+    case 0:
+        break;
+
+    default:
+        exit(0);
+    }
+
+#endif
+
+    umask(0);
+
+#if 0
+    fd = open("/dev/null", O_RDWR);
+    if (fd == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "open(\"/dev/null\") failed");
+        return NGX_ERROR;
+    }
+
+    if (dup2(fd, STDIN_FILENO) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "dup2(STDIN) failed");
+        return NGX_ERROR;
+    }
+
+    if (dup2(fd, STDOUT_FILENO) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "dup2(STDOUT) failed");
+        return NGX_ERROR;
+    }
+
+    if (dup2(fd, STDERR_FILENO) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, errno, "dup2(STDERR) failed");
+        return NGX_ERROR;
+    }
+
+    if (fd > STDERR_FILENO) {
+        if (close(fd) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, log, errno, "close() failed");
+            return NGX_ERROR;
+        }
+    }
+#endif
+
+    return NGX_OK;
+}