From 1a1901f459a9b330b9e29df5f56828821a8365d5 Mon Sep 17 00:00:00 2001
From: Tobias Ulmer <tu@emlix.com>
Date: Mon, 18 Feb 2019 18:03:15 +0100
Subject: [PATCH] eio: implement dup()

Signed-off-by: Tobias Ulmer <tu@emlix.com>
---
 generic/eio.lua | 16 ++++++++++++++++
 generic/leio.c  | 19 +++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/generic/eio.lua b/generic/eio.lua
index 676d193..f7178b0 100644
--- a/generic/eio.lua
+++ b/generic/eio.lua
@@ -407,6 +407,22 @@ function eio.setunbuffered(file)
     end
 end
 
+--- Duplicate a file descriptor. See dup(2) for details.
+-- @param oldfd File descriptor to duplicate.
+-- @return New file descriptor or false on error.
+-- @return Error object on failure.
+function eio.dup(oldfd)
+    local rc, errstring
+
+    rc, errstring = leio.dup(oldfd)
+    if not rc then
+        return false,
+            err.new("duplicating file descriptor failed: %s", errstring)
+    end
+    return rc
+end
+
+
 --- Duplicate a file descriptor. See dup(2) for details.
 -- @param oldfd File descriptor to duplicate.
 -- @param newfd Duplicated file descritor. If the file descriptor was open
diff --git a/generic/leio.c b/generic/leio.c
index 6c21e36..a55e4e7 100644
--- a/generic/leio.c
+++ b/generic/leio.c
@@ -409,6 +409,24 @@ eio_setunbuffered(lua_State *lua)
 	return 1;
 }
 
+static int
+eio_dup(lua_State *lua)
+{
+	int oldfd, rc;
+
+	oldfd = luaL_checkinteger(lua, 1);
+
+	rc = dup(oldfd);
+	if (rc < 0) {
+		lua_pushboolean(lua, 0);
+		lua_pushstring(lua, strerror(errno));
+		return 2;
+	}
+
+	lua_pushnumber(lua, rc);
+	return 1;
+}
+
 static int
 eio_dup2(lua_State *lua)
 {
@@ -475,6 +493,7 @@ eio_cloexec(lua_State *lua)
 static luaL_Reg lib[] = {
   { "cloexec", eio_cloexec },
   { "close", eio_close },
+  { "dup", eio_dup },
   { "dup2", eio_dup2 },
   { "fclose", eio_fclose },
   { "fdopen", eio_fdopen },
-- 
2.39.5