From e4686ff7864f0a2719092a19e9f19b2908968097 Mon Sep 17 00:00:00 2001
From: Gregory Gauthier <gregory.gauthier@perspectum.com>
Date: Wed, 4 Feb 2026 16:29:56 +0000
Subject: [PATCH] use older stat tools for dos; newer stat tools for linux

---
 src/cnadd.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/cnadd.c b/src/cnadd.c
index 4413542..c1dca06 100644
--- a/src/cnadd.c
+++ b/src/cnadd.c
@@ -11,10 +11,19 @@ int ensure_directory_exists(const char *path) {
     struct stat st;
     
     if (stat(path, &st) == 0) {
-        /* Path exists, check if it's a directory using bit test */
+        /* Path exists, check if it's a directory */
+#if defined(__MSDOS__) || defined(__DOS__)
+        /* DOS/Turbo C: use bit test because S_ISDIR macro may be missing */
         if ((st.st_mode & S_IFMT) == S_IFDIR) {
             return 1;
-        } else {
+        }
+#else
+        /* Unix/Linux/Windows modern: use standard POSIX macro */
+        if (S_ISDIR(st.st_mode)) {
+            return 1;
+        }
+#endif
+        else {
             fprintf(stderr, "Error: %s exists but is not a directory\n", path);
             return 0;
         }