feat: recognize rsync old-dirs aliases

src/client/client_cli.c

@@ -125,6 +125,7 @@ typedef enum {
   OPT_POS_INT,
   OPT_NONNEG_INT,
   OPT_ULL,
+  OPT_UNSUPPORTED,
 } OptKind;
 
 typedef struct {
@@ -153,6 +154,8 @@ static const OptionEntry OPTION_TABLE[] = {
     {"--sparse", "-S", OPT_FLAG, offsetof(Config, preserve_sparse)},
     {"--inplace", NULL, OPT_FLAG, offsetof(Config, inplace)},
     {"--checksum", NULL, OPT_FLAG, offsetof(Config, checksum)},
+    {"--dirs", "--old-dirs", OPT_UNSUPPORTED, 0},
+    {"--old-d", NULL, OPT_UNSUPPORTED, 0},
 
     {"--source-dir", NULL, OPT_STRING, offsetof(Config, send_directory)},
     {"--dest-dir", NULL, OPT_STRING, offsetof(Config, receive_root_directory)},
@@ -203,6 +206,11 @@ static int apply_table_option(Config* config, const OptionEntry* entry, const ch
     *(unsigned long long*)field = v;
     return 0;
   }
+  case OPT_UNSUPPORTED:
+    log_message(LOG_LEVEL_ERROR,
+                "%s requires --dirs, which is not implemented; refusing to ignore option",
+                entry->name);
+    return -1;
   }
   return -1;
 }

src/client/usage.c

@@ -21,6 +21,8 @@ void print_usage(void) {
   printf("  -p <port>           SSH port (default: 22)\n");
   printf("  --progress          Show transfer progress\n");
   printf("  --delete            Delete files on receiver not in source\n");
+  printf(
+      "  --dirs, --old-dirs, --old-d  Transfer directories without recursing (not implemented)\n");
   printf("  --exclude <pattern> Exclude files matching pattern\n");
   printf("  --include <pattern> Only include files matching pattern\n");
   printf("  --exclude-from <file> Read exclude patterns from file\n");