From 7a2322761a4fc47cb13da87219857e08c99afc05 Mon Sep 17 00:00:00 2001
From: Angus Hollands <goosey15@gmail.com>
Date: Mon, 20 Apr 2020 10:19:52 +0000
Subject: [PATCH 1/3] Fix nullity checks for parameter expansion

---
 bash.md | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/bash.md b/bash.md
index 001186ee6..40ed7d768 100644
--- a/bash.md
+++ b/bash.md
@@ -214,12 +214,13 @@ echo ${STR^^}  #=> "HELLO WORLD!" (all uppercase)
 
 ### Default values
 
-| `${FOO:-val}`        | `$FOO`, or `val` if not set |
-| `${FOO:=val}`        | Set `$FOO` to `val` if not set |
-| `${FOO:+val}`        | `val` if `$FOO` is set |
-| `${FOO:?message}`    | Show error message and exit if `$FOO` is not set |
+| `${FOO:-val}`        | `$FOO`, or `val` if unset (or null) |
+| `${FOO:=val}`        | Set `$FOO` to `val` if unset (or null) |
+| `${FOO:+val}`        | `val` if `$FOO` is set (and not null) |
+| `${FOO:?message}`    | Show error message and exit if `$FOO` is unset (or is null) |
+
+Omitting the `:` removes the (non)nullity checks, e.g. `${FOO-val}` expands to `val` if unset otherwise `$FOO`.
 
-The `:` is optional (eg, `${FOO=word}` works)
 
 Loops
 -----

From 0361fa173bbc6e280685743e500cb1a188461110 Mon Sep 17 00:00:00 2001
From: Angus Hollands <goosey15@gmail.com>
Date: Mon, 20 Apr 2020 11:21:31 +0100
Subject: [PATCH 2/3] Update bash.md

---
 bash.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bash.md b/bash.md
index 40ed7d768..3f6b85efb 100644
--- a/bash.md
+++ b/bash.md
@@ -1,4 +1,4 @@
----
+(---
 title: Bash scripting
 category: CLI
 layout: 2017/sheet
@@ -217,7 +217,7 @@ echo ${STR^^}  #=> "HELLO WORLD!" (all uppercase)
 | `${FOO:-val}`        | `$FOO`, or `val` if unset (or null) |
 | `${FOO:=val}`        | Set `$FOO` to `val` if unset (or null) |
 | `${FOO:+val}`        | `val` if `$FOO` is set (and not null) |
-| `${FOO:?message}`    | Show error message and exit if `$FOO` is unset (or is null) |
+| `${FOO:?message}`    | Show error message and exit if `$FOO` is unset (or null) |
 
 Omitting the `:` removes the (non)nullity checks, e.g. `${FOO-val}` expands to `val` if unset otherwise `$FOO`.
 

From bf22b55008d2cbf4625d22be129c4c121009bca8 Mon Sep 17 00:00:00 2001
From: "Rico Sta. Cruz" <rstacruz@users.noreply.github.com>
Date: Sat, 13 Jun 2020 10:11:51 +1000
Subject: [PATCH 3/3] Update bash.md

---
 bash.md | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/bash.md b/bash.md
index 3f6b85efb..e9bb11ff8 100644
--- a/bash.md
+++ b/bash.md
@@ -1,4 +1,4 @@
-(---
+---
 title: Bash scripting
 category: CLI
 layout: 2017/sheet
@@ -211,17 +211,17 @@ echo ${STR^}   #=> "Hello world!" (uppercase 1st letter)
 echo ${STR^^}  #=> "HELLO WORLD!" (all uppercase)
 ```
 
-
 ### Default values
 
-| `${FOO:-val}`        | `$FOO`, or `val` if unset (or null) |
-| `${FOO:=val}`        | Set `$FOO` to `val` if unset (or null) |
-| `${FOO:+val}`        | `val` if `$FOO` is set (and not null) |
-| `${FOO:?message}`    | Show error message and exit if `$FOO` is unset (or null) |
+| Expression        | Description                                              |
+| ----------------- | -------------------------------------------------------- |
+| `${FOO:-val}`     | `$FOO`, or `val` if unset (or null)                      |
+| `${FOO:=val}`     | Set `$FOO` to `val` if unset (or null)                   |
+| `${FOO:+val}`     | `val` if `$FOO` is set (and not null)                    |
+| `${FOO:?message}` | Show error message and exit if `$FOO` is unset (or null) |
 
 Omitting the `:` removes the (non)nullity checks, e.g. `${FOO-val}` expands to `val` if unset otherwise `$FOO`.
 
-
 Loops
 -----
 {: .-three-column}