From e47f06a56b4e10e7f0f5a5ba2bc7415009b9b1df Mon Sep 17 00:00:00 2001
From: Glenn Jackman <jackman@pythian.com>
Date: Wed, 14 Aug 2024 17:07:16 -0400
Subject: [PATCH 1/6] WIP: variables concept

---
 .../commands-and-arguments/.meta/config.json  |   3 +-
 concepts/commands-and-arguments/about.md      |   2 +-
 concepts/variables/.meta/config.json          |   7 ++
 concepts/variables/about.md                   |   0
 concepts/variables/introduction.md            | 101 ++++++++++++++++++
 concepts/variables/links.json                 |   1 +
 config.json                                   |   5 +
 7 files changed, 117 insertions(+), 2 deletions(-)
 create mode 100644 concepts/variables/.meta/config.json
 create mode 100644 concepts/variables/about.md
 create mode 100644 concepts/variables/introduction.md
 create mode 100644 concepts/variables/links.json

diff --git a/concepts/commands-and-arguments/.meta/config.json b/concepts/commands-and-arguments/.meta/config.json
index 369535e3..7801669e 100644
--- a/concepts/commands-and-arguments/.meta/config.json
+++ b/concepts/commands-and-arguments/.meta/config.json
@@ -3,7 +3,8 @@
     "glennj"
   ],
   "contributors": [
-    "IsaacG"
+    "IsaacG",
+    "kotp"
   ],
   "blurb": "Types of commands; argument splitting; writing scripts."
 }
diff --git a/concepts/commands-and-arguments/about.md b/concepts/commands-and-arguments/about.md
index 5357603d..fe9b4050 100644
--- a/concepts/commands-and-arguments/about.md
+++ b/concepts/commands-and-arguments/about.md
@@ -1,4 +1,4 @@
-# Introduction
+# About
 
 ## Shells
 
diff --git a/concepts/variables/.meta/config.json b/concepts/variables/.meta/config.json
new file mode 100644
index 00000000..aaa0f126
--- /dev/null
+++ b/concepts/variables/.meta/config.json
@@ -0,0 +1,7 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "contributors": [],
+  "blurb": "Variables and variable expansions."
+}
diff --git a/concepts/variables/about.md b/concepts/variables/about.md
new file mode 100644
index 00000000..e69de29b
diff --git a/concepts/variables/introduction.md b/concepts/variables/introduction.md
new file mode 100644
index 00000000..61c34ca7
--- /dev/null
+++ b/concepts/variables/introduction.md
@@ -0,0 +1,101 @@
+# Introduction
+
+## Variables
+
+Variables are a place to hold data.
+Bash has two kinds of data: strings and arrays.
+We'll talk about arrays later.
+
+You assign a variable like this
+```bash
+varname="the value"
+```
+
+~~~~exercism/note
+**Important** -- there must be _no spaces_ around the equal sign!
+
+This is a variable assignment
+```bash
+x=10
+```
+
+This calls the command `x` with two arguments, `=` and `10`!
+```bash
+x = 10
+```
+~~~~
+
+## Variable Names
+
+A variable name consists of uppercase letters, lowercase letters, numbers and underscore.
+It cannot start with a number.
+
+~~~~exercism/caution
+It is best practice to **avoid using ALLCAPS variable names**.
+The shell uses this convention for its parameters, and you don't want to accidentally override shell parameters that have special meaning.
+For example: [1][1], [2][2], [3][3]
+
+[1]: https://stackoverflow.com/q/27555060/7552
+[2]: https://stackoverflow.com/q/28310594/7552
+[3]: https://unix.stackexchange.com/q/114596/4667
+~~~~
+
+## Parameters
+
+Variables can also be called "parameters".
+The difference is that a variable is assigned by you, the programmer.
+A parameter can be a read-only variable that is set by the shell.
+
+Some important parameters used by or set by bash include:
+
+* `PATH` -- a colon-separated list of directories used to find external commands.
+* `IFS` -- the "internal field separator". We'll see how it's used below.
+* `PWD` -- your current working directory.
+* `RANDOM` -- a pseudo-random integer between 0 and 32767.
+* `BASH_VERSION` -- the version string of the running instance of bash.
+
+## Parameter Expansion
+
+You get the value of a parameter with the `$varname` syntax.
+
+```bash
+x=10
+echo "The value of x is $x"
+```
+
+To prevent the variable name from being confused with surrounding text, you can enclose the variable name in braces.
+For example to print the string `10x10`
+
+```bash
+echo "${x}x$x"
+# or
+echo "${x}x${x}"
+```
+
+Some [style guides][google-style-guide] recommend using braces in most cases for readability.
+
+## Positional Parameters
+
+As we discussed in the [Commands and Arguments][cmds-args] lesson, commands can take arguments.
+Bash scripts are no exception.
+The arguments to the current instance of bash are called "positional parameters".
+They can be retrieved with these special parameters:
+
+* `$1` -- the first positional parameter
+* `$2` ... `$9` -- subsequent parameters
+* `${10}` ... -- double digits require braces.
+* `$0` -- the name of the current script.
+
+### Special Positional Parameters
+
+$@
+$*
+IFS
+
+## Command Substitution
+
+## More on Parameter Expansion
+
+
+[google-style-guide]: https://google.github.io/styleguide/shellguide.html
+[cmds-args]: https://exercism.org/tracks/bash/concepts/commands-and-arguments
diff --git a/concepts/variables/links.json b/concepts/variables/links.json
new file mode 100644
index 00000000..fe51488c
--- /dev/null
+++ b/concepts/variables/links.json
@@ -0,0 +1 @@
+[]
diff --git a/config.json b/config.json
index ced8abe3..1f692a1e 100644
--- a/config.json
+++ b/config.json
@@ -1223,6 +1223,11 @@
       "uuid": "07e48a7d-7dd0-477c-96e1-23d2558d507d",
       "slug": "commands-and-arguments",
       "name": "Commands and Arguments"
+    },
+    {
+      "uuid": "e29f24ae-3c3b-479a-9333-d733c1ff8fb4",
+      "slug": "variables",
+      "name": "Variables"
     }
   ],
   "key_features": [

From ca4b9e81062081a6e5be8097bd81dcbea62c69f6 Mon Sep 17 00:00:00 2001
From: Glenn Jackman <jackman@pythian.com>
Date: Wed, 14 Aug 2024 17:07:16 -0400
Subject: [PATCH 2/6] variables concept

---
 concepts/variables/introduction.md | 99 +++++++++++++++++++++++-------
 1 file changed, 77 insertions(+), 22 deletions(-)

diff --git a/concepts/variables/introduction.md b/concepts/variables/introduction.md
index 61c34ca7..ba0d5069 100644
--- a/concepts/variables/introduction.md
+++ b/concepts/variables/introduction.md
@@ -14,30 +14,13 @@ varname="the value"
 ~~~~exercism/note
 **Important** -- there must be _no spaces_ around the equal sign!
 
-This is a variable assignment
-```bash
-x=10
-```
+When there are spaces, like in this example,
 
-This calls the command `x` with two arguments, `=` and `10`!
 ```bash
 x = 10
 ```
-~~~~
-
-## Variable Names
-
-A variable name consists of uppercase letters, lowercase letters, numbers and underscore.
-It cannot start with a number.
-
-~~~~exercism/caution
-It is best practice to **avoid using ALLCAPS variable names**.
-The shell uses this convention for its parameters, and you don't want to accidentally override shell parameters that have special meaning.
-For example: [1][1], [2][2], [3][3]
 
-[1]: https://stackoverflow.com/q/27555060/7552
-[2]: https://stackoverflow.com/q/28310594/7552
-[3]: https://unix.stackexchange.com/q/114596/4667
+bash is going to call the **command** `x` with the **two arguments** `=` and `10`!
 ~~~~
 
 ## Parameters
@@ -54,6 +37,21 @@ Some important parameters used by or set by bash include:
 * `RANDOM` -- a pseudo-random integer between 0 and 32767.
 * `BASH_VERSION` -- the version string of the running instance of bash.
 
+## Parameter Names
+
+A variable name consists of uppercase letters, lowercase letters, numbers and underscore.
+It cannot start with a number.
+
+~~~~exercism/caution
+It is best practice to **avoid using ALLCAPS variable names**.
+The shell uses this convention for its parameters, and you don't want to accidentally override shell parameters that have special meaning.
+For example: [1][1], [2][2], [3][3]
+
+[1]: https://stackoverflow.com/q/27555060/7552
+[2]: https://stackoverflow.com/q/28310594/7552
+[3]: https://unix.stackexchange.com/q/114596/4667
+~~~~
+
 ## Parameter Expansion
 
 You get the value of a parameter with the `$varname` syntax.
@@ -88,14 +86,71 @@ They can be retrieved with these special parameters:
 
 ### Special Positional Parameters
 
-$@
-$*
-IFS
+There are some "special" parameters that help you work with the positional parameters.
+
+* `$#` expands to the _number_ of positional parameters.
+* `"$@"` expands to the list of all of the positional parameters, each as a separate word.
+* `"$*"` expands to a single string of all the positional parameters joined together by a character.
+  * The join character is _the first character_ of the `$IFS` variable, which is a space by default.
+
+The `"$@"` is the safest way to pass positional parameters to another command while keeping them safely quoted.
+It is also what you will use to loop over them:
+
+```bash
+for arg in "$@"; do
+    do_something_with "$arg"
+done
+```
 
 ## Command Substitution
 
+A very frequent operation you will do in bash scripts is to capture the output of a command and store it in a variable.
+To do this, you will use the command substitution syntax, like this:
+
+```bash
+var=$(command)
+```
+
+For example, to upper-case a string, you can do this:
+
+```bash
+text="Hello world!"
+uppercase=$(echo "$text" | tr '[:lower:]' '[:upper:]')
+echo "$uppercase"
+# => HELLO WORLD!
+```
+
 ## More on Parameter Expansion
 
+Bash has many builtin facilities to manipulate variables and strings so that you don't need to call out to external commands.
+
+* Uppercasing text: in the previous section I showed how to use `tr` to upper case some text. To do it in bash:
+
+  ```bash
+  echo "${text^^}"
+  ```
+
+* Provide a default value if the variable is empty.
+
+  ```bash
+  default="nothing here"
+  result=""
+  echo "${result:-$default}"
+  # => nothing here
+  ```
+
+* Search and replace.
+
+  ```bash
+  text="Hello world!"
+  echo "${text//[aeiou]/X}"
+  # => HXllX wXrld!"
+  ```
+
+There are many other interesting parameter expansions. 
+Read about them [in the manual][param-exp].
+
 
 [google-style-guide]: https://google.github.io/styleguide/shellguide.html
 [cmds-args]: https://exercism.org/tracks/bash/concepts/commands-and-arguments
+[param-exp]: https://www.gnu.org/software/bash/manual/bash.html#Shell-Parameter-Expansion

From 3053b4a1ee88a9a4d0f7d1b167943a1844239ffa Mon Sep 17 00:00:00 2001
From: Glenn Jackman <glenn.jackman@gmail.com>
Date: Sun, 18 Aug 2024 11:38:07 -0400
Subject: [PATCH 3/6] review feedback

---
 concepts/variables/introduction.md | 42 ++++++++++++++++++------------
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/concepts/variables/introduction.md b/concepts/variables/introduction.md
index ba0d5069..d7979e0d 100644
--- a/concepts/variables/introduction.md
+++ b/concepts/variables/introduction.md
@@ -2,7 +2,7 @@
 
 ## Variables
 
-Variables are a place to hold data.
+_Variables_ are a place to hold data.
 Bash has two kinds of data: strings and arrays.
 We'll talk about arrays later.
 
@@ -23,28 +23,27 @@ x = 10
 bash is going to call the **command** `x` with the **two arguments** `=` and `10`!
 ~~~~
 
-## Parameters
-
-Variables can also be called "parameters".
-The difference is that a variable is assigned by you, the programmer.
-A parameter can be a read-only variable that is set by the shell.
+Variables can also be called _parameters_.
+The two terms will be used interchangably in this document.
 
 Some important parameters used by or set by bash include:
 
 * `PATH` -- a colon-separated list of directories used to find external commands.
-* `IFS` -- the "internal field separator". We'll see how it's used below.
+* `IFS` -- the "internal field separator".
+   We'll see how it's used below.
 * `PWD` -- your current working directory.
+   It will be the same value as the output of the `pwd` command.
 * `RANDOM` -- a pseudo-random integer between 0 and 32767.
 * `BASH_VERSION` -- the version string of the running instance of bash.
 
-## Parameter Names
+## Variable Names
 
-A variable name consists of uppercase letters, lowercase letters, numbers and underscore.
+A variable name consists of _uppercase letters, lowercase letters, numbers and underscore_.
 It cannot start with a number.
 
 ~~~~exercism/caution
 It is best practice to **avoid using ALLCAPS variable names**.
-The shell uses this convention for its parameters, and you don't want to accidentally override shell parameters that have special meaning.
+The shell uses this convention for its parameters, and you don't want to accidentally overwrite shell parameters that have special meaning.
 For example: [1][1], [2][2], [3][3]
 
 [1]: https://stackoverflow.com/q/27555060/7552
@@ -70,13 +69,13 @@ echo "${x}x$x"
 echo "${x}x${x}"
 ```
 
-Some [style guides][google-style-guide] recommend using braces in most cases for readability.
+Some [style guides][google-style-guide] recommend using braces in most cases for readability and/or consistency.
 
 ## Positional Parameters
 
 As we discussed in the [Commands and Arguments][cmds-args] lesson, commands can take arguments.
 Bash scripts are no exception.
-The arguments to the current instance of bash are called "positional parameters".
+The arguments to the current instance of bash are called _positional parameters_.
 They can be retrieved with these special parameters:
 
 * `$1` -- the first positional parameter
@@ -84,9 +83,12 @@ They can be retrieved with these special parameters:
 * `${10}` ... -- double digits require braces.
 * `$0` -- the name of the current script.
 
+Arguments to a shell function are also positional parameters, handled just like this.
+We'll see more about functions in a later lesson.
+
 ### Special Positional Parameters
 
-There are some "special" parameters that help you work with the positional parameters.
+There are some _special parameters_ that help you work with the positional parameters.
 
 * `$#` expands to the _number_ of positional parameters.
 * `"$@"` expands to the list of all of the positional parameters, each as a separate word.
@@ -94,7 +96,7 @@ There are some "special" parameters that help you work with the positional param
   * The join character is _the first character_ of the `$IFS` variable, which is a space by default.
 
 The `"$@"` is the safest way to pass positional parameters to another command while keeping them safely quoted.
-It is also what you will use to loop over them:
+It is also what you will use to loop over the positional parameters:
 
 ```bash
 for arg in "$@"; do
@@ -102,10 +104,12 @@ for arg in "$@"; do
 done
 ```
 
+In practice, `"$@"` is used more often than `"$*"`.
+
 ## Command Substitution
 
 A very frequent operation you will do in bash scripts is to capture the output of a command and store it in a variable.
-To do this, you will use the command substitution syntax, like this:
+To do this, you will use _command substitution_.
 
 ```bash
 var=$(command)
@@ -124,12 +128,16 @@ echo "$uppercase"
 
 Bash has many builtin facilities to manipulate variables and strings so that you don't need to call out to external commands.
 
-* Uppercasing text: in the previous section I showed how to use `tr` to upper case some text. To do it in bash:
+* Uppercasing text.
+  In the previous section I showed how to use `tr` to upper case some text.
+  To do it in bash:
 
   ```bash
   echo "${text^^}"
   ```
 
+  Similarly, `${text,,}` lowercases the value.
+
 * Provide a default value if the variable is empty.
 
   ```bash
@@ -147,7 +155,7 @@ Bash has many builtin facilities to manipulate variables and strings so that you
   # => HXllX wXrld!"
   ```
 
-There are many other interesting parameter expansions. 
+There are many other interesting parameter expansions: extract a substring, get the string length, _assign_ a default value, remove text from the start or end of the value, and more.
 Read about them [in the manual][param-exp].
 
 

From 62458bec6c9af74b0a22bd03fdf5d2e352ed0301 Mon Sep 17 00:00:00 2001
From: Glenn Jackman <glenn.jackman@gmail.com>
Date: Sun, 18 Aug 2024 11:47:02 -0400
Subject: [PATCH 4/6] add links

---
 concepts/commands-and-arguments/links.json |  4 ++--
 concepts/variables/links.json              | 11 ++++++++++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/concepts/commands-and-arguments/links.json b/concepts/commands-and-arguments/links.json
index ef91ec22..f8e46a20 100644
--- a/concepts/commands-and-arguments/links.json
+++ b/concepts/commands-and-arguments/links.json
@@ -1,10 +1,10 @@
 [
   {
-    "description": "Commands and Arguments in the Bash Guide",
+    "description": "\"Commands and Arguments\" in the BashGuide",
     "url": "https://mywiki.wooledge.org/BashGuide/CommandsAndArguments"
   },
   {
-    "description": "Shell Operation in the bash manual",
+    "description": "\"Shell Operation\" in the bash manual",
     "url": "https://www.gnu.org/software/bash/manual/bash.html#Shell-Operation"
   }
 ]
diff --git a/concepts/variables/links.json b/concepts/variables/links.json
index fe51488c..56dd277b 100644
--- a/concepts/variables/links.json
+++ b/concepts/variables/links.json
@@ -1 +1,10 @@
-[]
+[
+  {
+    "description": "\"Parameters\" in the BashGuide",
+    "url": "https://mywiki.wooledge.org/BashGuide/Parameters"
+  },
+  {
+    "description": "\"Shell Parameters\" in the bash manual",
+    "url": "https://www.gnu.org/software/bash/manual/bash.html#Shell-Parameters"
+  }
+]

From a26c1c50e2582020a4f8c4c8617fadc5faa05395 Mon Sep 17 00:00:00 2001
From: Glenn Jackman <glenn.jackman@gmail.com>
Date: Tue, 20 Aug 2024 19:31:48 -0400
Subject: [PATCH 5/6] feedback for the introduction; add Isaac as a
 contributor; add the about doc

---
 concepts/variables/.meta/config.json |   4 +-
 concepts/variables/about.md          | 164 +++++++++++++++++++++++++++
 concepts/variables/introduction.md   |   2 +-
 3 files changed, 168 insertions(+), 2 deletions(-)

diff --git a/concepts/variables/.meta/config.json b/concepts/variables/.meta/config.json
index aaa0f126..c6619966 100644
--- a/concepts/variables/.meta/config.json
+++ b/concepts/variables/.meta/config.json
@@ -2,6 +2,8 @@
   "authors": [
     "glennj"
   ],
-  "contributors": [],
+  "contributors": [
+    "IsaacG"
+  ],
   "blurb": "Variables and variable expansions."
 }
diff --git a/concepts/variables/about.md b/concepts/variables/about.md
index e69de29b..05252373 100644
--- a/concepts/variables/about.md
+++ b/concepts/variables/about.md
@@ -0,0 +1,164 @@
+# About
+
+## Variables
+
+_Variables_ are a place to hold data.
+Bash has two kinds of data: strings and arrays.
+We'll talk about arrays later.
+
+You assign a variable like this
+```bash
+name="value"
+```
+
+~~~~exercism/note
+**Important** -- there must be _no spaces_ around the equal sign!
+
+When there are spaces, like in this example,
+
+```bash
+x = 10
+```
+
+bash is going to call the **command** `x` with the **two arguments** `=` and `10`!
+~~~~
+
+Variables can also be called _parameters_.
+The two terms will be used interchangably in this document.
+
+Some important parameters used by or set by bash include:
+
+* `PATH` -- a colon-separated list of directories used to find external commands.
+* `IFS` -- the "internal field separator".
+   We'll see how it's used below.
+* `PWD` -- your current working directory.
+   It will be the same value as the output of the `pwd` command.
+* `RANDOM` -- a pseudo-random integer between 0 and 32767.
+* `BASH_VERSION` -- the version string of the running instance of bash.
+
+## Variable Names
+
+A variable name consists of _uppercase letters, lowercase letters, numbers and underscore_.
+It cannot start with a number.
+
+~~~~exercism/caution
+It is best practice to **avoid using ALLCAPS variable names**.
+The shell uses this convention for its parameters, and you don't want to accidentally overwrite shell parameters that have special meaning.
+For example: [1][1], [2][2], [3][3]
+
+[1]: https://stackoverflow.com/q/27555060/7552
+[2]: https://stackoverflow.com/q/28310594/7552
+[3]: https://unix.stackexchange.com/q/114596/4667
+~~~~
+
+## Parameter Expansion
+
+You get the value of a parameter with the `$varname` syntax.
+
+```bash
+x=10
+echo "The value of x is $x"
+```
+
+To prevent the variable name from being confused with surrounding text, you can enclose the variable name in braces.
+For example to print the string `10x10`
+
+```bash
+echo "${x}x$x"
+# or
+echo "${x}x${x}"
+```
+
+Some [style guides][google-style-guide] recommend using braces in most cases for readability and/or consistency.
+
+## Positional Parameters
+
+As we discussed in the [Commands and Arguments][cmds-args] lesson, commands can take arguments.
+Bash scripts are no exception.
+The arguments to the current instance of bash are called _positional parameters_.
+They can be retrieved with these special parameters:
+
+* `$1` -- the first positional parameter
+* `$2` ... `$9` -- subsequent parameters
+* `${10}` ... -- double digits require braces.
+* `$0` -- the name of the current script.
+
+Arguments to a shell function are also positional parameters, handled just like this.
+We'll see more about functions in a later lesson.
+
+### Special Positional Parameters
+
+There are some _special parameters_ that help you work with the positional parameters.
+
+* `$#` expands to the _number_ of positional parameters.
+* `"$@"` expands to the list of all of the positional parameters, each as a separate word.
+* `"$*"` expands to a single string of all the positional parameters joined together by a character.
+  * The join character is _the first character_ of the `$IFS` variable, which is a space by default.
+
+The `"$@"` is the safest way to pass positional parameters to another command while keeping them safely quoted.
+It is also what you will use to loop over the positional parameters:
+
+```bash
+for arg in "$@"; do
+    do_something_with "$arg"
+done
+```
+
+In practice, `"$@"` is used more often than `"$*"`.
+
+## Command Substitution
+
+A very frequent operation you will do in bash scripts is to capture the output of a command and store it in a variable.
+To do this, you will use _command substitution_.
+
+```bash
+var=$(command)
+```
+
+For example, to upper-case a string, you can do this:
+
+```bash
+text="Hello world!"
+uppercase=$(echo "$text" | tr '[:lower:]' '[:upper:]')
+echo "$uppercase"
+# => HELLO WORLD!
+```
+
+## More on Parameter Expansion
+
+Bash has many builtin facilities to manipulate variables and strings so that you don't need to call out to external commands.
+
+* Uppercasing text.
+  In the previous section I showed how to use `tr` to upper case some text.
+  To do it in bash:
+
+  ```bash
+  echo "${text^^}"
+  ```
+
+  Similarly, `${text,,}` lowercases the value.
+
+* Provide a default value if the variable is empty.
+
+  ```bash
+  default="nothing here"
+  result=""
+  echo "${result:-$default}"
+  # => nothing here
+  ```
+
+* Search and replace.
+
+  ```bash
+  text="Hello world!"
+  echo "${text//[aeiou]/X}"
+  # => HXllX wXrld!"
+  ```
+
+There are many other interesting parameter expansions: extract a substring, get the string length, _assign_ a default value, remove text from the start or end of the value, and more.
+Read about them [in the manual][param-exp].
+
+
+[google-style-guide]: https://google.github.io/styleguide/shellguide.html
+[cmds-args]: https://exercism.org/tracks/bash/concepts/commands-and-arguments
+[param-exp]: https://www.gnu.org/software/bash/manual/bash.html#Shell-Parameter-Expansion
diff --git a/concepts/variables/introduction.md b/concepts/variables/introduction.md
index d7979e0d..501e3070 100644
--- a/concepts/variables/introduction.md
+++ b/concepts/variables/introduction.md
@@ -8,7 +8,7 @@ We'll talk about arrays later.
 
 You assign a variable like this
 ```bash
-varname="the value"
+name="value"
 ```
 
 ~~~~exercism/note

From 513e8784be48656c238aa3c5d19ba68d10eb604a Mon Sep 17 00:00:00 2001
From: Glenn Jackman <glenn.jackman@gmail.com>
Date: Wed, 21 Aug 2024 20:25:11 -0400
Subject: [PATCH 6/6] Blurbs

---
 concepts/commands-and-arguments/.meta/config.json | 2 +-
 concepts/commands-and-arguments/links.json        | 2 +-
 concepts/variables/.meta/config.json              | 2 +-
 concepts/variables/links.json                     | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/concepts/commands-and-arguments/.meta/config.json b/concepts/commands-and-arguments/.meta/config.json
index 7801669e..1dd5452b 100644
--- a/concepts/commands-and-arguments/.meta/config.json
+++ b/concepts/commands-and-arguments/.meta/config.json
@@ -6,5 +6,5 @@
     "IsaacG",
     "kotp"
   ],
-  "blurb": "Types of commands; argument splitting; writing scripts."
+  "blurb": "Bash scripts are written as sequences of commands. Learn about command and arguments, types of commands, and the essentials about writing scripts."
 }
diff --git a/concepts/commands-and-arguments/links.json b/concepts/commands-and-arguments/links.json
index f8e46a20..fddee526 100644
--- a/concepts/commands-and-arguments/links.json
+++ b/concepts/commands-and-arguments/links.json
@@ -1,6 +1,6 @@
 [
   {
-    "description": "\"Commands and Arguments\" in the BashGuide",
+    "description": "\"Commands and Arguments\" in the Bash Guide",
     "url": "https://mywiki.wooledge.org/BashGuide/CommandsAndArguments"
   },
   {
diff --git a/concepts/variables/.meta/config.json b/concepts/variables/.meta/config.json
index c6619966..82bdabd6 100644
--- a/concepts/variables/.meta/config.json
+++ b/concepts/variables/.meta/config.json
@@ -5,5 +5,5 @@
   "contributors": [
     "IsaacG"
   ],
-  "blurb": "Variables and variable expansions."
+  "blurb": "Learn about variables in bash, and some of the variable expansions."
 }
diff --git a/concepts/variables/links.json b/concepts/variables/links.json
index 56dd277b..d5c4d7e9 100644
--- a/concepts/variables/links.json
+++ b/concepts/variables/links.json
@@ -1,6 +1,6 @@
 [
   {
-    "description": "\"Parameters\" in the BashGuide",
+    "description": "\"Parameters\" in the Bash Guide",
     "url": "https://mywiki.wooledge.org/BashGuide/Parameters"
   },
   {