make nlen a size_t to better hold diffs between pointers etc
diff --git a/src/main.c b/src/main.c
index 862a946..d53a862 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2059,7 +2059,7 @@
            */
           char *p = strchr(nextarg, '=');
           long size = 0;
-          int nlen;
+          size_t nlen;
           char is_file;
           if(!p)
             p = strchr(nextarg, '@');