1 files changed, 4 insertions, 0 deletions
diff --git a/bash.md b/bash.md
index 26c5b5e..e6e54f3 100644
--- a/bash.md
+++ b/bash.md
@@ -21,3 +21,7 @@ Remove longest from start
 Loop over files
 
     for file in glob/*; do something $file; done
+
+## Conditionals
+
+* `-z`: is empty string