From b86b50153e938f8e917f91e336ec0242fabaf518 Mon Sep 17 00:00:00 2001
From: koalaman <vidar@vidarholen.net>
Date: Wed, 7 May 2014 20:34:35 -0700
Subject: [PATCH] Created SC2139 (markdown)

---
 SC2139.md | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 SC2139.md

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+## This expands when defined, not when used. Consider escaping.
+
+### Problematic code:
+
+    alias whereami="echo $PWD"
+
+### Correct code:
+
+    alias whereami='echo $PWD'
+
+### Rationale:
+
+With double quotes, this particular alias will be defined as `echo /home/me`, so it will always print the same path. This is rarely intended.
+
+By using single quotes or escaping any expansions, we define the alias as `echo $PWD`, which will be expanded when we use the alias. This is the far more common use case.
+
+### Contraindications
+
+If you don't mind that your alias definition is expanded at compile time, you can ignore this warning.
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