lf: prevent self dos

.config/lf/preview/preview

@@ -23,7 +23,7 @@ video() {
 }
 
 text() {
-    for cmd in bat batcat cat; do
+    for cmd in bat batcat head; do
         command -v $cmd >/dev/null 2>&1 && break
     done
     case $cmd in
@@ -35,10 +35,11 @@ text() {
                 --pager=never \
                 --tabs=4 \
                 --theme=base16 \
+                --line-range=":$h" \
                 --terminal-width="$((w - 2))" "$@" "$f"
             ;;
-        cat)
-            $cmd "$f"
+        head)
+            head -n "$h" "$f"
             ;;
     esac
 }