diff --git a/knowledge base/find.md b/knowledge base/find.md
index 241ddf3..693cd54 100644
--- a/knowledge base/find.md	
+++ b/knowledge base/find.md	
@@ -46,7 +46,8 @@ find . -type f -o -type l \
 
 # Print quoted file paths.
 # %p is for path.
-find . -type f -printf '%p\n'
+find . -type f -printf '"%p"\n'
+find . -type f -printf "'%p'\n"
 
 # Sort files by size.
 # %s is for size, %p is for path.
diff --git a/knowledge base/vim.md b/knowledge base/vim.md
index 9a295a4..6d58391 100644
--- a/knowledge base/vim.md	
+++ b/knowledge base/vim.md	
@@ -8,6 +8,9 @@
 42gg
 :42<CR>
 
+# Delete all file's lines.
+:1,$d
+
 # Substitute 4-spaces indentations with tabs.
 :%s/    /\t/g