2 files changed, 50 insertions, 6 deletions

diff --git a/src/lfs.c b/src/lfs.c
index 1b74a31..2b9d292 100644
--- a/src/lfs.c
+++ b/src/lfs.c
@@ -172,6 +172,15 @@ typedef struct dir_data {
 
 #endif
 
+#if _POSIX_VERSION >= 200809L
+#define UTIME_FUNC(dirp, name, utb)  utimensat(dirp ? dirfd(dirp) : 0, name, utb, 0)
+#define UTIME_STRUCT                 struct timespec
+#else
+#define UTIME_FUNC(dirp, name, utb)  utime(name, utb)
+#define UTIME_STRUCT                 struct utimbuf
+#endif
+
+
 #ifdef _WIN32
 #define lfs_mkdir _mkdir
 #else
@@ -820,17 +829,39 @@ static const char *mode2string(mode_t mode)
 static int file_utime(lua_State * L)
 {
   const char *file = luaL_checkstring(L, 1);
-  struct utimbuf utb, *buf;
+  UTIME_STRUCT utb[2];
+  UTIME_STRUCT *buf;
+#ifndef _WIN32
+  DIR* dirp = NULL;
+#endif
 
   if (lua_gettop(L) == 1)       /* set to current date/time */
     buf = NULL;
   else {
-    utb.actime = (time_t) luaL_optnumber(L, 2, 0);
-    utb.modtime = (time_t) luaL_optinteger(L, 3, utb.actime);
-    buf = &utb;
+#if _POSIX_VERSION >= 200809L
+    lua_Number acctime = luaL_optnumber(L, 2, 0);
+    lua_Number modtime = luaL_optnumber(L, 3, acctime);
+    utb[0].tv_sec = acctime;
+    utb[0].tv_nsec = (acctime - utb[0].tv_sec) * 1000000000;
+    utb[1].tv_sec = modtime;
+    utb[1].tv_nsec = (modtime - utb[1].tv_sec) * 1000000000;
+    if (file[0] != '/') {
+      dirp = opendir(".");
+    }
+#else
+    utb[0].actime = (time_t) luaL_optnumber(L, 2, 0);
+    utb[0].modtime = (time_t) luaL_optnumber(L, 3, utb[0].actime);
+#endif
+    buf = utb;
   }
 
-  return pushresult(L, utime(file, buf), NULL);
+  int res = UTIME_FUNC(dirp, file, buf);
+#ifndef _WIN32
+  if (dirp) {
+    closedir(dirp);
+  }
+#endif
+  return pushresult(L, res, NULL);
 }
 
 
diff --git a/tests/test.lua b/tests/test.lua
index 3ace810..5d00e44 100644
--- a/tests/test.lua
+++ b/tests/test.lua
@@ -79,6 +79,19 @@ assert (new_att.modification == testdate, "could not set modification time")
 io.write(".")
 io.flush()
 
+-- High-precision attributes
+local testdate_hi = os.time({ year = 2021, day = 1, month = 23, hour=0}) + 0.5555
+assert (lfs.touch (tmpfile, testdate_hi))
+local new_att_hi = assert (lfs.attributes (tmpfile))
+if new_att_hi.modification ~= testdate_hi then
+    io.write("\n")
+    io.write("warning: no support for high-precision timestamps\n")
+    io.flush()
+end
+
+io.write(".")
+io.flush()
+
 -- Change access and modification time
 local testdate1 = os.time({ year = 2007, day = 10, month = 2, hour=0})
 local testdate2 = os.time({ year = 2007, day = 11, month = 2, hour=0})
@@ -194,7 +207,7 @@ io.write(".")
 io.flush()
 
 -- Stressing directory iterator
-count = 0
+local count = 0
 for i = 1, 4000 do
         for file in lfs.dir (tmp) do
                 count = count + 1