Merge branch 'master' into patch-1

CONTRIBUTING.md

@@ -27,7 +27,7 @@ First time setup:
 docker-compose build
 
 # First-time setup
-docker-compose run --rm web bundle install
+docker-compose run --rm web bundle install && yarn
 ```
 
 Starting the server:

_data/categories.yml

@@ -3,12 +3,15 @@ names:
   - Analytics
   - Ansible
   - Apps
+  - C-like
   - CLI
   - CSS
+  - Databases
   - Devops
   - Elixir
   - Git
   - HTML
+  - Java & JVM
   - JavaScript
   - JavaScript libraries
   - Jekyll
@@ -16,6 +19,8 @@ names:
   - Markup
   - macOS
   - Node.js
+  - PHP
+  - Python
   - Rails
   - React
   - Ruby

_includes/about-the-site.html

@@ -2,7 +2,7 @@
   <div class="container">
     <p class='blurb'>
     <strong><a href="{{ base }}">{{ site.title }}</a></strong> is a collection of cheatsheets I've written over the years.
-      Suggestions and corrections? <a href='https://github.com/rstacruz/cheatsheets/issues'>Send them in</a>.
+      Suggestions and corrections? <a href='https://github.com/rstacruz/cheatsheets/issues/907'>Send them in</a>.
       <i class='fleuron'></i>
       I'm <a href="http://ricostacruz.com">Rico Sta. Cruz</a>. 
       Check out my <a href="http://ricostacruz.com/til">Today I learned blog</a> for more.

_layouts/2017/home.html

@@ -77,7 +77,7 @@
     <div class='message item missing-message'>
       <h3>See something missing?</h3>
       <p>
-        <a class='push-button' href='{{ site.github.repository_url }}/issues/new?title=Cheatsheet%20request:%20APP_NAME_HERE'>Request cheatsheet</a>
+        <a class='push-button' href='{{ site.github.repository_url }}/issues/907'>Request cheatsheet</a>
       </p>
     </div>
   </div>

analytics.md

@@ -1,6 +1,7 @@
 ---
 title: Analytics libraries
 layout: 2017/sheet
+category: Analytics
 ---
 
 ### Mixpanel

awscli.md

@@ -15,6 +15,7 @@ aws ec2 start-instances --instance-ids i-12345678c
 
 ```
 aws s3 ls s3://mybucket
+aws s3 rm s3://mybucket/folder --recursive
 aws s3 cp myfolder s3://mybucket/folder --recursive
 aws s3 sync myfolder s3://mybucket/folder --exclude *.tmp
 ```

backbone.md

@@ -2,6 +2,7 @@
 title: Backbone.js
 layout: 2017/sheet
 updated: 2017-09-04
+category: JavaScript libraries
 ---
 
 ### Binding events

bash.md

@@ -3,7 +3,7 @@ title: Bash scripting
 category: CLI
 layout: 2017/sheet
 tags: [Featured]
-updated: 2017-08-26
+updated: 2018-11-19
 keywords:
   - Variables
   - Functions
@@ -154,8 +154,8 @@ echo ${STR:-5:5}  # "world"
 
 ```bash
 SRC="/path/to/foo.cpp"
-BASE=${STR##*/}   #=> "foo.cpp" (basepath)
+BASE=${SRC##*/}   #=> "foo.cpp" (basepath)
-DIR=${SRC%$BASE}  #=> "/path/to" (dirpath)
+DIR=${SRC%$BASE}  #=> "/path/to/" (dirpath)
 ```
 
 ### Substitution
@@ -325,6 +325,8 @@ Note that `[[` is actually a command/program that returns either `0` (true) or `
 | ---                      | ---                   |
 | `[[ -z STRING ]]`        | Empty string          |
 | `[[ -n STRING ]]`        | Not empty string      |
+| `[[ STRING == STRING ]]` | Equal                 |
+| `[[ STRING != STRING ]]` | Not Equal             |
 | ---                      | ---                   |
 | `[[ NUM -eq NUM ]]`      | Equal                 |
 | `[[ NUM -ne NUM ]]`      | Not equal             |
@@ -392,6 +394,11 @@ if [[ X ]] && [[ Y ]]; then
 fi
 ```
 
+```bash
+# Equal
+if [[ "$A" == "$B" ]]
+```
+
 ```bash
 # Regex
 if [[ "A" =~ "." ]]
@@ -439,6 +446,7 @@ echo ${Fruits[@]:3:2}       # Range (from position 3, length 2)
 
 ```bash
 Fruits=("${Fruits[@]}" "Watermelon")    # Push
+Fruits+=('Watermelon')                  # Also Push
 Fruits=( ${Fruits[@]/Ap*/} )            # Remove by regex match
 unset Fruits[2]                         # Remove one item
 Fruits=("${Fruits[@]}")                 # Duplicate
@@ -497,6 +505,7 @@ History
 
 ### Operations
 
+| `!!` | Execute last command again |         
 | `!!:s/<FROM>/<TO>/` | Replace first occurrence of `<FROM>` to `<TO>` in most recent command |
 | `!!:gs/<FROM>/<TO>/` | Replace all occurrences of `<FROM>` to `<TO>` in most recent command |
 | `!$:t` | Expand only basename from last parameter of most recent command |
@@ -506,7 +515,9 @@ History
 
 ### Slices
 
-| `!!:n` | Expand only `n`th token from most recent command (command is `0`; first param is `1`) |
+| `!!:n` | Expand only `n`th token from most recent command (command is `0`; first argument is `1`) |
+| `!^` | Expand first argument from most recent command |
+| `!$` | Expand last token from most recent command |
 | `!!:n-m` | Expand range of tokens from most recent command |
 | `!!:n-$` | Expand `n`th token to last from most recent command |
 
@@ -651,6 +662,16 @@ read -n 1 ans    # Just one character
 
 See [Special parameters](http://wiki.bash-hackers.org/syntax/shellvars#special_parameters_and_shell_variables).
 
+### Go to previous directory
+
+```bash
+pwd # /home/user/foo
+cd bar/
+pwd # /home/user/foo/bar
+cd -
+pwd # /home/user/foo
+```
+
 ## Also see
 {: .-one-column}
 

bootstrap.md

@@ -3,6 +3,7 @@ title: Bootstrap
 layout: 2017/sheet
 prism_languages: [scss, haml, html]
 weight: -1
+category: CSS
 description: |
   .container .row .col-md-6, @screen-sm-min, .form-control, grids, .modal-content, tooltips, and other Bootstrap CSS examples.
 ---

bulma.md

@@ -1,9 +1,10 @@
 ---
 title: Bulma
+category: CSS
 layout: 2017/sheet
 prism_languages: [css, html]
 weight: -1
-updated: 2018-03-06
+updated: 2018-11-19
 authors:
   - github: benolot
 description: |
@@ -61,7 +62,6 @@ The following classes modify the **state**.
 .is-loading
 ```
 
-
 ### Typography Helpers
 
 The following classes modify the **font-size**
@@ -92,3 +92,21 @@ The following classes **transform** the text
 | `.is-capitalized`  | Transforms the **first character** of each word to **uppercase**   |
 | `.is-lowercase`    | Transforms **all** characters to **lowercase**                     |
 | `.is-uppercase`    | Transforms **all** characters to **uppercase**                     |
+
+### WYSIWYG Content
+
+```html
+<div class="content">
+  <!-- start WYSIWYG contents -->
+  <h1>Heading</h1>
+  <p>Paragraph</p>
+
+  <ul>
+    <li>Item 1</li>
+    <li>Item 2</li>
+  </ul>
+  <!-- end WYSIWYG contents -->
+</div>
+```
+
+To provide default stylings for commonly generated WYSIWYG contents, use the `.content` class.

c_preprocessor.md

@@ -1,5 +1,6 @@
 ---
 title: C Preprocessor
+category: C-like
 ---
 
 ### Compiling

circle.md

@@ -1,5 +1,6 @@
 ---
 title: CircleCI
+category: Devops
 ---
 
 ## circle.yml

composer.md

@@ -30,6 +30,7 @@ All composer commands, depending on your install, may need to use `php composer.
 | ---                       | ---                             |
 | `composer update laravel` | Update a certain package        |
 | `composer update vendor/*`| Update all packages in a folder |
+| `composer update --lock`  | Update lock file hash without updating any packages |
 
 
 
@@ -45,4 +46,4 @@ All composer commands, depending on your install, may need to use `php composer.
 
 | Command                   | Description                                                 |
 | ---                       | ---                                                         |
-| `composer remove laravel` | Remove new package to composer.json and uninstall it        |
+| `composer remove laravel` | Remove new package from composer.json and uninstall it      |

csharp7.md

@@ -0,0 +1,195 @@
+---
+title: C# 7
+category: C-like
+updated: 2018-12-06
+layout: 2017/sheet
+prism_languages: [csharp]
+description: |
+  A quick overview of C# 7
+---
+
+### Out Variables
+
+```csharp
+public void PrintCoordinates(Point p)
+{
+    p.GetCoordinates(out int x, out int y);
+    WriteLine($"({x}, {y})");
+}
+```
+
+`out` is used to declare a variable at the point where it is passed as an argument.
+
+### Pattern Matching
+
+#### Is-expressions with patterns
+
+```csharp
+public void PrintStars(object o)
+{
+    if (o is null) return;     // constant pattern "null"
+    if (!(o is int i)) return; // type pattern "int i"
+    WriteLine(new string('*', i));
+}
+```
+
+#### Switch statements with patterns
+
+```csharp
+switch(shape)
+{
+    case Circle c:
+        WriteLine($"circle with radius {c.Radius}");
+        break;
+    case Rectangle s when (s.Length == s.Height):
+        WriteLine($"{s.Length} x {s.Height} square");
+        break;
+    case Rectangle r:
+        WriteLine($"{r.Length} x {r.Height} rectangle");
+        break;
+    default:
+        WriteLine("<unknown shape>");
+        break;
+    case null:
+        throw new ArgumentNullException(nameof(shape));
+}
+```
+
+### Tuples
+
+#### Tuple type
+
+```csharp
+(string, string, string) LookupName(long id) // tuple return type
+{
+    ... // retrieve first, middle and last from data storage
+    return (first, middle, last); // tuple literal
+}
+```
+
+```csharp
+var names = LookupName(id);
+WriteLine($"found {names.Item1} {names.Item3}.");
+```
+
+#### Tuple elements with name
+
+```csharp
+(string first, string middle, string last) LookupName(long id) // tuple elements have names
+```
+
+```csharp
+var names = LookupName(id);
+WriteLine($"found {names.first} {names.last}.");
+```
+
+#### Tuple Literals
+
+```csharp
+   return (first: first, middle: middle, last: last); // named tuple elements in a literal
+```
+
+#### Tuple Deconstruction
+
+```csharp
+(var first, var middle, var last) = LookupName(id1);
+WriteLine($"found {first} {last}.");
+```
+or
+```csharp
+var (first, middle, last) = LookupName(id1); // var outside
+```
+or
+```csharp
+(first, middle, last) = LookupName(id2); // assign onto existing variables
+```
+
+
+### Local Functions
+
+```csharp
+public int Fibonacci(int x)
+{
+    if (x < 0) throw new ArgumentException("Less negativity please!", nameof(x));
+    return Fib(x).current;
+
+    (int current, int previous) Fib(int i)
+    {
+        if (i == 0) return (1, 0);
+        var (p, pp) = Fib(i - 1);
+        return (p + pp, p);
+    }
+}
+```
+
+### Literal Improvements
+
+#### Digit Separator inside numbers literals
+
+```csharp
+var d = 123_456;
+var x = 0xAB_CD_EF;
+```
+
+#### Binary Literals
+
+```csharp
+var b = 0b1010_1011_1100_1101_1110_1111;
+```
+
+### Ref Returns and Locals
+
+```csharp
+public ref int Find(int number, int[] numbers)
+{
+    for (int i = 0; i < numbers.Length; i++)
+    {
+        if (numbers[i] == number) 
+        {
+            return ref numbers[i]; // return the storage location, not the value
+        }
+    }
+    throw new IndexOutOfRangeException($"{nameof(number)} not found");
+}
+
+int[] array = { 1, 15, -39, 0, 7, 14, -12 };
+ref int place = ref Find(7, array); // aliases 7's place in the array
+place = 9; // replaces 7 with 9 in the array
+WriteLine(array[4]); // prints 9
+```
+
+### More Expression Bodied Members
+
+C# 7.0 adds accessors, constructors and finalizers to the list of things that can have expression bodies:
+
+```csharp
+class Person
+{
+    private static ConcurrentDictionary<int, string> names = new ConcurrentDictionary<int, string>();
+    private int id = GetId();
+
+    public Person(string name) => names.TryAdd(id, name); // constructors
+    ~Person() => names.TryRemove(id, out *);              // destructors
+    public string Name
+    {
+        get => names[id];                                 // getters
+        set => names[id] = value;                         // setters
+    }
+}
+```
+
+### Throw Expressions 
+
+```csharp
+class Person
+{
+    public string Name { get; }
+    public Person(string name) => Name = name ?? throw new ArgumentNullException(name);
+    public string GetFirstName()
+    {
+        var parts = Name.Split(" ");
+        return (parts.Length > 0) ? parts[0] : throw new InvalidOperationException("No name!");
+    }
+    public string GetLastName() => throw new NotImplementedException();
+}
+```

css-grid.md

@@ -0,0 +1,255 @@
+---
+title: CSS Grid
+category: CSS
+updated: 2018-12-06
+layout: 2017/sheet
+prism_languages: [css]
+---
+
+### Container
+
+```css
+.grid-container {
+```
+{: .-setup}
+
+```css
+  /* Display properties */
+  display: grid;
+  display: inline-grid;
+  display: subgrid;
+```
+
+```css
+  /* Columns and rows */
+  grid-template-columns: 1rem 2rem 1rem; /* Measurement units */
+  grid-template-columns: 25% 50% 25%; /* Percentage units */
+  grid-template-columns: 1rem auto 1rem 2fr; /* Fill remaining widths with auto or fr units */
+  grid-template-columns: repeat(12, 1fr); /* Repeat columns without needing to write them */
+  
+  grid-template-rows: 1rem 10% auto repeat(5, 10px); /* Mix any group, same rules work for rows */
+```
+
+```css
+  /* Automatic columns and rows */
+
+  grid-auto-columns: 10px; /* No matter how many columns of content end up in the grid, each column will be this same width */
+  grid-auto-rows: 1rem; /* No matter how many rows of content end up in the grid, each row will be this same height */
+```
+
+```css
+  /* Areas */
+  grid-tamplate-areas:
+    "header header"
+    "main aside"
+    "footer footer"; /* Grid-style */
+
+  grid-template-areas: "header header" "main aside" "footer footer"; /* Inline-style */
+```
+
+```css
+  /* Template shorthand */
+  grid-template:
+    "header header" auto
+    "main aside" 100vh
+    "footer footer" 10rem
+    / 80% 20%;
+
+  /* The above is the same as below long-hand */
+  grid-template-columns: 80% 20%;
+  grid-template-rows: auto 100vh 10rem;
+  grid-tamplate-areas:
+    "header header"
+    "main aside"
+    "footer footer";
+```
+
+```css
+  /* Gaps */
+  grid-row-gap: 1rem;
+  grid-column-gap: 0.5rem; /* Define values separately */
+
+  grid-gap: 1rem 0.5rem; /* Short-hand for row / column */
+  grid-gap: 1rem; /* Gap in both dimensions */
+```
+
+```css
+  /* Item justification (horizontal or column alignment) */
+  justify-items: start; /* Align items to the left */
+  justify-items: center; /* Align items centered within its column */
+  justify-items: end; /* Align items to the right */
+  justify-items: stretch; /* (default) Fills available area (horizontally) */
+```
+
+```css
+  /* Item alignment (vertical or row alignment) */
+  align-items: start; /* Align items to the top */
+  align-items: center; /* Align items centered within its row */
+  align-items: end; /* Align items to the bottom */
+  align-items: stretch; /* (default) Fills available area (vertically) */
+```
+
+```css
+  /* Place item shorthand */
+  place-items: start stretch;
+
+  /* The above is the same as below long-hand */
+  align-items: start;
+  justify-items: stretch;
+```
+
+```css
+  /* Content justification (horizontal or column alignment) */
+  justify-content: start; /* Align content to the left */
+  justify-content: center; /* Align content centered horizontally within the grid */
+  justify-content: end; /* Align content to the right */
+  justify-content: stretch; /* (default) Fills available area (horizontally) */
+
+  justify-content: space-around; /* Chooses a space for both sides of the columns like a left and right margin */
+  justify-content: space-between; /* Chooses a space to go between columns, no margins on outside of content */
+  justify-content: space-evenly; /* Chooses a space that goes between all columns and edges consistently */
+```
+
+```css
+  /* Content alignment (horizontal or column alignment) */
+  align-content: start; /* Align content to the top */
+  align-content: center; /* Align content centered vertically within the grid */
+  align-content: end; /* Align content to the bottom */
+  align-content: stretch; /* (default) Fills available area (vertically) */
+
+  align-content: space-around; /* Chooses a space for the top and bottom of the rows like a top and bottom margin */
+  align-content: space-between; /* Chooses a space to go between rows, no margins on outside of content */
+  align-content: space-evenly; /* Chooses a space that goes between all rows and edges consistently */
+```
+
+```css
+  /* Place item shorthand */
+  place-content: center start;
+
+  /* The above is the same as below long-hand */
+  align-content: center;
+  justify-content: start;
+```
+
+```css
+  /* Automatic grid positioning */
+
+  grid-auto-flow: row; /* Left-to-right rows, then top-to-bottom*/
+  grid-auto-flow: column; /* Top-to-bottom columns, then left-to-right */
+  grid-auto-flow: dense; /* Responds with best-guess on left-to-right, top-to-bottom order with advanced layouts */
+```
+
+```css
+  /* There is one final shorthand for all container properties in one */
+
+  /* Explicit grid columns, rows, and areas */
+  grid:
+    "header header" auto
+    "main aside" 100vh
+    "footer footer" 10rem
+    / 80% 20%; /* You can include a template as the only value, which is equivalent to below */
+  grid-template:
+    "header header" auto
+    "main aside" 100vh
+    "footer footer" 10rem
+    / 80% 20%; /* Which is again equivalent to below */
+  grid-template-columns: 80% 20%;
+  grid-template-rows: auto 100vh 10rem;
+  grid-tamplate-areas:
+    "header header"
+    "main aside"
+    "footer footer";
+
+  /* Automatic grid flows */
+  grid: 1rem / auto-flow dense 1fr; /* You can include rows, a flow, and automatic columns, which is equivalent to below */
+  grid-template-rows: 1rem;
+  grid-auto-flow: dense;
+  grid-auto-columns: 1fr;
+
+  grid: auto-flow dense 1rem / repeat(10, 10%); /* Conversely, you can do the same thing with automatic rows, and defined columns */
+  grid-auto-flow: dense;
+  grid-auto-rows: 1rem;
+  grid-template-columns: repeat(10, 10%);
+```
+
+```css
+}
+```
+{: .-setup}
+
+### Child
+
+```css
+.grid-child {
+```
+{: .-setup}
+
+```css
+  /* Column position */
+  grid-column-start: 1;
+  grid-column-end: 2;
+
+  grid-column: 1 / 2; /* Short hand */
+  grid-column: 1 / span 2; /* Span 2 columns without explicitly defining an endpoint */
+  grid-column: 1; /* Start in and occupy a single column */
+```
+
+```css
+  /* Row position */
+  grid-row-start: 2;
+  grid-row-end: 4;
+
+  grid-row: 2 / 4; /* Short hand */
+  grid-row: 2 / span 3;/* Span 3 rows without explicitly defining an endpoint */
+  grid-row: 1; /* Start in and occupy a single row */
+```
+
+```css
+  /* Area positioning */
+  grid-area: header; /* You can use a named grid area from the container */
+
+  grid-area: 2 / 1 / 4 / 2; /* Or you can use positioning. This is equivalent to... */
+  grid-row-start: 2;
+  grid-column-start: 1;
+  grid-row-end: 4;
+  grid-column-end: 2;
+```
+
+```css
+  /* Self justification (horizontal or column alignment) */
+  justify-self: start; /* Align item to the left */
+  justify-self: center; /* Align item centered within its column */
+  justify-self: end; /* Align item to the right */
+  justify-self: stretch; /* (default) Fills available area (horizontally) */
+```
+
+```css
+  /* Self alignment (vertical or row alignment) */
+  align-self: start; /* Align item to the top */
+  align-self: center; /* Align item centered within its row */
+  align-self: end; /* Align item to the bottom */
+  align-self: stretch; /* (default) Fills available area (vertically) */
+```
+
+```css
+  /* Placement shorthand */
+  place-self: start stretch;
+
+  /* The above is the same as below long-hand */
+  align-self: start;
+  justify-self: stretch;
+```
+
+```css
+}
+```
+{: .-setup}
+
+
+## References
+{: .-one-column}
+
+ * [GRID: A simple visual cheatsheet](http://grid.malven.co/)
+ * [CSS Tricks: A Complete Guide to Grid](https://css-tricks.com/snippets/css/complete-guide-grid/)
+ * [Browser support](https://caniuse.com/#feat=css-grid)
+ 

css.md

@@ -170,23 +170,25 @@ background: linear-gradient(to bottom, rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)),
 
 ### Properties
 
-| Property                     | Value                                              |
+| Property                     | Value                                                    |
-| ---------------------------- | -------------------------------------------------- |
+| ---------------------------- | -------------------------------------------------------- |
-| `animation:`                 | _(shorthand)_                                      |
+| `animation:`                 | _(shorthand)_                                            |
-| `animation-name:`            | `<name>`                                           |
+| `animation-name:`            | `<name>`                                                 |
-| `animation-delay:`           | `<time>ms`                                         |
+| `animation-duration:`        | `<time>ms`                                               |
-| `animation-duration:`        | `<time>ms`                                         |
+| `animation-timing-function:` | `ease` `linear` `ease-in` `ease-out` `ease-in-out`       |
-| `animation-direction:`       | `normal` `reverse` `alternate` `alternate-reverse` |
+| `animation-delay:`           | `<time>ms`                                               |
-| `animation-iteration-count:` | `infinite` `<number>`                              |
+| `animation-iteration-count:` | `infinite` `<number>`                                    |
-| `animation-timing-function:` | `ease` `linear` `ease-in` `ease-out` `ease-in-out` |
+| `animation-direction:`       | `normal` `reverse` `alternate` `alternate-reverse`       |
+| `animation-fill-mode:`       | `none` `forwards` `backwards` `both` `initial` `inherit` |
+| `animation-play-state:`      | `normal` `reverse` `alternate` `alternate-reverse`       |
 {: .-key-values}
 
 ### Shorthand
 
-|              | name     | duration | timing-function | delay   | count      | direction           |
+|              | name     | duration | timing-function | delay   | count      | direction           | fill-mode | play-state |
-| ------------ | -------- | -------- | --------------- | ------- | ---------- | ------------------- |
+| ------------ | -------- | -------- | --------------- | ------- | ---------- | ------------------- | --------- | ---------- |
-| `animation:` | `bounce` | `300ms`  | `linear`        | `100ms` | `infinite` | `alternate-reverse` |
+| `animation:` | `bounce` | `300ms`  | `linear`        | `100ms` | `infinite` | `alternate-reverse` | `both`    | `reverse`  |
-|              | name     | duration | timing-function | delay   | count      | direction           |
+|              | name     | duration | timing-function | delay   | count      | direction           | fill-mode | play-state |
 {: .-css-breakdown}
 
 ### Example
@@ -195,6 +197,7 @@ background: linear-gradient(to bottom, rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)),
 animation: bounce 300ms linear 0s infinite normal;
 animation: bounce 300ms linear infinite;
 animation: bounce 300ms linear infinite alternate-reverse;
+animation: bounce 300ms linear 2s infinite alternate-reverse forwards normal;
 ```
 
 ### Event

curl.md

@@ -17,6 +17,7 @@ updated: 2017-09-20
 ```bash
 -v           # --verbose
 -vv          # Even more verbose
+-s           # --silent
 ```
 
 ```bash
@@ -27,6 +28,7 @@ updated: 2017-09-20
 
 ```bash
 -X POST          # --request
+-L               # follow link if page redirects 
 ```
 
 ### Data

docker-compose.md

@@ -196,3 +196,21 @@ services:
     extra_hosts:
       - "somehost:192.168.1.100"
 ```
+
+### Network
+
+```yaml
+# creates a custom network called `frontend`
+networks:
+  frontend:
+```
+
+### External network
+
+```yaml
+# join a pre-existing network
+networks:
+  default:
+    external:
+      name: frontend
+```

editorconfig.md

@@ -4,6 +4,7 @@ layout: 2017/sheet
 prism_languages: [ini]
 weight: -1
 updated: 2017-09-04
+category: Apps
 ---
 
 ### Short example

emacs.md

@@ -1,5 +1,6 @@
 ---
 title: Emacs
+category: CLI
 ---
 
 ### Movements

emmet.md

@@ -0,0 +1,178 @@
+---
+title: Emmet
+category: Markup
+layout: 2017/sheet
+prism_languages: [html, css]
+updated: 2018-11-10
+intro: |
+  Emmet is a markup language for expanding CSS rules into HTML
+---
+
+### Child: >
+
+```css
+nav>ul>li
+```
+Expands to
+```html
+<nav>
+  <ul>
+    <li></li>
+  </ul>
+</nav>
+```
+
+
+### Sibling: +
+
+```css
+section>p+p+p
+```
+Expands to
+```html
+<section>
+  <p></p>
+  <p></p>
+  <p></p>
+</section>
+```
+
+### Climb Up: ^
+
+```css
+section>header>h1^footer
+```
+Expands to
+```html
+<section>
+  <header>
+    <h1></h1>
+  </header>
+  <footer></footer>
+</section>
+```
+
+### Grouping: ()
+
+```css
+section>(header>nav>ul>li)+footer>p
+```
+Expands to
+```html
+<section>
+  <header>
+    <nav>
+      <ul>
+        <li></li>
+      </ul>
+    </nav>
+  </header>
+  <footer>
+    <p></p>
+  </footer>
+</section>
+```
+
+### Multiplication: \*
+
+```css
+ul>li*3
+```
+Expands to
+```html
+<ul>
+  <li></li>
+  <li></li>
+  <li></li>
+</ul>
+```
+
+### IDs and Classes: . #
+
+```css
+ul.menu>li.menu__item+li#id_item+li.menu__item#id_2
+```
+Expands to
+```html
+<ul>
+  <li class="menu__item"></li>
+  <li id="id_item"></li>
+  <li class="menu__item" id="id_2"></li>
+</ul>
+```
+
+### Numbering: $
+
+```css
+ul>li.item$*3
+ul>li.item$$*3
+ul>li.item$@-*3
+ul>li.item$@3*5
+```
+Expands to
+```html
+<ul>
+  <li class="item1"></li>
+  <li class="item2"></li>
+  <li class="item3"></li>
+</ul>
+<ul>
+  <li class="item01"></li>
+  <li class="item02"></li>
+  <li class="item03"></li>
+</ul>
+<ul>
+  <li class="item3"></li>
+  <li class="item2"></li>
+  <li class="item1"></li>
+</ul>
+<ul>
+  <li class="item3"></li>
+  <li class="item4"></li>
+  <li class="item5"></li>
+</ul>
+```
+
+### Attributes: []
+
+```css
+input[type="text"]
+div[data-attr="test"]
+```
+Expands to
+```html
+<input type="text" />
+<div data-attr="test"></div>
+```
+
+### Text: {}
+
+```css
+p{Lorem ipsum}
+```
+Expands to
+```html
+<p>Lorem ipsum</p>
+```
+
+### Implicit tags
+
+```css
+.default-block
+em>.default-inline
+ul>.default-list
+table>.default-table-row>.default-table-column
+```
+Expands to
+```html
+<div class="default-block"></div>
+<em><span class="default-inline"></span></em>
+<ul>
+  <li class="default-list"></li>
+</ul>
+<table>
+  <tr class="default-table-row">
+    <td class="default-table-column"></td>
+  </tr>
+</table>
+```

enzyme.md

@@ -2,7 +2,7 @@
 title: Enzyme
 category: React
 layout: 2017/sheet
-updated: 2017-10-12
+updated: 2018-04-27
 tags: [Featured]
 weight: -1
 keywords:
@@ -248,7 +248,7 @@ wrap.context()       // get full context
 
 ```js
 wrap.state('key')    // → any
-wrap.props('key')    // → any
+wrap.prop('key')    // → any
 wrap.context('key')  // → any
 ```
 

es2018.md

@@ -0,0 +1,5 @@
+---
+title: ES2018
+category: JavaScript
+redirect_to: /es6
+---

es6.md

@@ -6,7 +6,7 @@ tags: [Featured]
 updated: 2017-10-21
 weight: -10
 intro: |
-  A quick overview of new JavaScript features in ES2015, ES2016, ES2017 and beyond.
+  A quick overview of new JavaScript features in ES2015, ES2016, ES2017, ES2018 and beyond.
 ---
 
 ### Block scoping
@@ -69,6 +69,9 @@ See: [Binary and octal literals](https://babeljs.io/learn-es2015/#binary-and-oct
 "hello".repeat(3)
 "hello".includes("ll")
 "hello".startsWith("he")
+"hello".padStart(8) // "   hello"
+"hello".padEnd(8) // "hello   " 
+"hello".padEnd(8, '!') // hello!!!
 "\u1E9B\u0323".normalize("NFC")
 ```
 
@@ -154,6 +157,20 @@ promise
 ```
 {: data-line="2,3"}
 
+
+### Using promises with finally
+
+```js
+promise
+  .then((result) => { ··· })
+  .catch((error) => { ··· })
+  .finally(() => { // logic independent of success/error })
+```
+{: data-line="4"}
+
+The handler is called when the promise is fulfilled or rejected.
+
+
 ### Promise functions
 
 ```js
@@ -273,6 +290,17 @@ for (let {title, artist} of songs) {
 
 The assignment expressions work in loops, too.
 
+
+### Object destructuring
+
+```js
+const { id, ...detail } = song;
+```
+{: data-line="1"}
+
+Extract some keys individually and remaining keys in the object using rest (...) operator
+
+
 Spread
 ------
 
@@ -385,8 +413,12 @@ readFile('text.txt', (err, data) => {
 numbers.map(n => n * 2)
 // No curly braces = implicit return
 // Same as: numbers.map(function (n) { return n * 2 })
+numbers.map(n => ({
+  result: n * 2
+})
+// Implicitly returning objects requires parentheses around the object
 ```
-{: data-line="1"}
+{: data-line="1,4,5,6"}
 
 Like functions but with `this` preserved.
 See: [Fat arrows](https://babeljs.io/learn-es2015/#arrows-and-lexical-this)
@@ -446,6 +478,21 @@ let handlers = {
 
 See: [Object literal enhancements](https://babeljs.io/learn-es2015/#enhanced-object-literals)
 
+
+### Extract values
+
+```js
+const fatherJS = { age: 57, name: "Brendan Eich" }
+
+Object.values(fatherJS)
+// [57, "Brendan Eich"]
+Object.entries(fatherJS)
+// [["age", 57], ["name", "Brendan Eich"]]
+```
+
+{: data-line="3,5"}
+
+
 Modules
 -------
 

exunit.md

@@ -85,12 +85,18 @@ end
 
 
 ```elixir
-describe "a block" do
+defp my_hook(_context) do
-  setup [:my_hook]
+  # Invoked in every block in "a block"
+  {:ok, name: "John", age: 54}
 end
 
-defp my_hook(context) do
+describe "a block" do
-  # Invoked in every block in "a block"
+  setup [:my_hook]
+  
+  test "John's age", context do
+    assert context[:name] == "John"
+    assert context[:age] == 54
+  end
 end
 ```
 
@@ -98,4 +104,4 @@ end
 ## Also see
 {: .-one-column}
 
-- <http://devdocs.io/elixir/ex_unit/exunit#configure/1>
+* [ExUnit Docs](http://devdocs.io/elixir/ex_unit/exunit#configure/1)

factory_girl.md

@@ -1,5 +1,5 @@
 ---
 title: Factory Girl
-category: JavaScript libraries
+category: Ruby libraries
 redirect_to: /factory_bot
 ---

find.md

@@ -33,6 +33,14 @@ find <path> <conditions> <actions>
 -regex PATTERN
 ```
 
+```bash
+-size 8            # Exactly 8 512-bit blocks 
+-size -128c        # Smaller than 128 bytes
+-size 1440k        # Exactly 1440KiB
+-size +10M         # Larger than 10MiB
+-size +2G          # Larger than 2GiB
+```
+
 ```bash
 -newer   file.txt
 -newerm  file.txt        # modified newer than file.txt

flow.md

@@ -133,7 +133,7 @@ type Album = {
 ```js
 const a: Album = { } // ✓ OK
 a.name = 'Blue'      // ✓ OK
-a.name = null        // ✓ Error
+a.name = null        // ✗ Error
 a.name = undefined   // ✓ OK
 ```
 

git-extras.md

@@ -34,27 +34,31 @@ Also `git-bug` and `git-refactor`.
 
 ### Github
 
-     $ git fork strongloop/express
+    $ git fork strongloop/express
+    # sync your fork with the original repository:
+    $ git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
+    $ git fetch upstream; git merge upstream/master
+
 
 ### Tags
 
-     $ git release v1.0.0           # commit, tag, push-tags
+    $ git release v1.0.0           # commit, tag, push-tags
-     $ git delete-tag v1.0.0
+    $ git delete-tag v1.0.0
 
 ### Conveniences
 
-     $ git ignore "*.log"
+    $ git ignore "*.log"
 
 ### Locking
 
 Assumes that changes will not be committed.
 
-     $ git lock config/database.yml
+    $ git lock config/database.yml
-     $ git unlock config/database.yml
+    $ git unlock config/database.yml
 
 ### Etc
 
-     $ git obliterate secret.yml   # remove all references to it
+    $ git obliterate secret.yml   # remove all references to it
 
 ### References
 

git-log-format.md

@@ -54,7 +54,7 @@ See the next tables on format variables.
 | `%f` | commit subject, filename style |
 | `%b` | commit body |
 | --- | --- |
-| `%cd` | ref names |
+| `%d` | ref names |
 | `%e` | encoding |
 
 ## Author and committer

git-tricks.md

@@ -28,6 +28,9 @@ category: Git
     # delete remote branch
       git push origin :$branchname
       
+    # go back to previous branch
+      git checkout -
+      
 ## Collaboration
 
     # Rebase your changes on top of the remote master
@@ -86,7 +89,7 @@ Misc
 
     git rebase 76acada^
 
-## Misc
+### Misc
 
     # get current sha1 (?)
       git show-ref HEAD -s
@@ -133,3 +136,13 @@ Misc
     git log --grep="fixes things"  # search in commit messages
     git log -S"window.alert"       # search in code
     git log -G"foo.*"              # search in code (regex)
+
+## GPG Signing
+
+    git config set user.signingkey <GPG KEY ID>       # Sets GPG key to use for signing
+
+    git commit -m "Implement feature Y" --gpg-sign    # Or -S, GPG signs commit
+
+    git config set commit.gpgsign true                # Sign commits by default
+    git commit -m "Implement feature Y" --no-gpg-sign # Do not sign
+    

go.md

@@ -4,6 +4,7 @@ layout: 2017/sheet
 prism_languages: [go, bash]
 weight: -3
 tags: [Featured]
+category: C-like
 updated: 2017-09-15
 ---
 
@@ -198,6 +199,27 @@ switch day {
 
 See: [Switch](https://github.com/golang/go/wiki/Switch)
 
+### For loop
+
+```go
+  for count := 0; count <= 10; count++ {
+		fmt.Println("My counter is at", count)
+	}
+```
+
+See: [For loops](https://tour.golang.org/flowcontrol/1)
+
+### For-Range loop
+
+```go
+  entry := []string{"Jack","John","Jones"}
+  for i, val := range entry {
+    fmt.Printf("At position %d, the character %s is present\n", i, val)
+  }
+```
+
+See: [For-Range loops](https://gobyexample.com/range)
+
 ## Functions
 {: .-three-column}
 
@@ -485,7 +507,7 @@ See: [Methods](https://tour.golang.org/methods/1)
 ```go
 func (v *Vertex) Scale(f float64) {
   v.X = v.X * f
-  v.y = v.Y * f
+  v.Y = v.Y * f
 }
 ```
 {: data-line="1"}

graphql.md

@@ -2,6 +2,7 @@
 title: GraphQL
 layout: 2017/sheet
 updated: 2017-09-23
+category: Databases
 ---
 
 ## Intro

haml.md

@@ -0,0 +1,53 @@
+---
+title: Haml
+category: Markup
+layout: 2017/sheet
+prism_languages: [haml]
+---
+
+### Doctype
+
+```haml
+!!! 5
+```
+
+### Tags
+
+```haml
+%html
+  %head
+    %title
+  %body
+    %h1 Hello World
+    %br/
+```
+
+### Classes and ID's
+
+```haml
+%p.class-example
+.no-tag-defaults-to-div
+%div#butItCanBeIncluded
+```
+
+### Inline Attributes
+
+Either hash syntax works
+
+```haml
+%meta{ name: "viewport", content: "width=device-width, initial-scale=1.0" }
+%input{ :type => "text", :required => true }
+```
+
+### Ruby
+
+```haml
+-# This is a comment
+-# Anything starting with a hyphen signals to Haml that Ruby is coming
+- @arr = [1, 2, 3]
+- @str = "test"
+-# Equal signals output
+= render partial: "shared/header"
+= yield
+= link_to page_url
+```

homebrew.md

@@ -2,6 +2,7 @@
 title: Homebrew
 layout: 2017/sheet
 weight: -3
+category: CLI
 ---
 
 ### Commands

httpie.md

@@ -47,6 +47,7 @@ Print options:
                          # h: response headers
                          # b: response body
     --pretty=none        # all | colors | format
+    --json | -j          # Response is serialized as a JSON object.
 ```
 
 #### Authentication

jekyll.md

@@ -139,7 +139,7 @@ Markup
 {% for post in site.posts %}
   <a href="{{ post.url }}">
     <h2>{{ post.title }}</h2>
-    <p>{{ post.date | date_to_string }}</h2>
+    <p>{{ post.date | date_to_string }}</p>
   </a>
 {% endfor %}
 ```

knex.md

@@ -2,6 +2,7 @@
 title: Knex
 layout: 2017/sheet
 updated: 2017-09-23
+category: Databases
 intro: |
   [Knex](http://knexjs.org/) is an SQL query builder for Node.js.
   This guide targets v0.13.0.
@@ -43,7 +44,7 @@ knex('users')
 ```
 {: data-line="2"}
 
-See: [Select](#elect-1)
+See: [Select](#select-1)
 
 ### Insert
 
@@ -475,7 +476,7 @@ See: [Delete](http://knexjs.org/#Builder-del)
 
 ### Setting up
 
-#### Creates knexfile.js
+#### Create knexfile.js
 
 ```
 ./node_modules/.bin/knex init
@@ -485,6 +486,7 @@ See: [Delete](http://knexjs.org/#Builder-del)
 
 ```
 knex migrate:make migration_name
+knex migrate:make migration_name --env production
 ```
 
 #### Run migrations
@@ -498,6 +500,7 @@ knex migrate:latest --env production
 
 ```
 knex migrate:rollback
+knex migrate:rollback --env production
 ```
 
 See: [Migrations](http://knexjs.org/#Migrations)

kotlin.md

@@ -0,0 +1,402 @@
+---
+title: Kotlin
+layout: 2017/sheet
+updated: 2018-12-06
+category: Java & JVM
+prism_languages: [kotlin]
+intro: |
+    [Kotlin](http://kotlinlang.org/) is a statically typed programming language for modern multiplatform applications.
+---
+
+Variables
+---------
+{: .-three-column}
+
+### Mutability
+
+```kotlin
+var mutableString: String = "Adam"
+val immutableString: String = "Adam"
+val inferredString = "Adam"
+```
+
+### Strings
+
+```kotlin
+val name = "Adam"
+val greeting = "Hello, " + name
+val greetingTemplate = "Hello, $name"
+```
+
+### Numbers
+
+```kotlin
+val intNum = 10
+val doubleNum = 10.0
+val longNum = 10L
+val floatNum = 10.0F
+```
+
+### Booleans
+
+```kotlin
+val trueBoolean = true
+val falseBoolean = false
+val andCondition = trueBoolean && falseBoolean
+val orCondition = trueBoolean || falseBoolean
+```
+
+### Static Fields
+
+```kotlin
+class Person {
+    companion object {
+        val NAME_KEY = "name_key"
+    }
+}
+
+val key = Person.NAME_KEY
+```
+
+Null Safety
+-----------
+{: .-two-column}
+
+### Nullable properties
+
+```kotlin
+val cannotBeNull: String = null // Invalid
+val canBeNull: String? = null // Valid
+
+val cannotBeNull: Int = null // Invalid
+val canBeNull: Int? = null // Valid
+```
+
+### Checking for null
+
+```kotlin
+val name: String? = "Adam"
+
+if (name != null && name.length > 0) {
+    print("String length is ${name.length}")
+} else {
+    print("String is empty.")
+}
+```
+
+### Safe Operator
+
+```kotlin
+val nullableStringLength: Int? = nullableString?.length
+val nullableDepartmentHead: String? = person?.department?.head?.name
+```
+
+### Elvis Operator
+
+```kotlin
+val nonNullStringLength: Int = nullableString?.length ?: 0
+val nonNullDepartmentHead: String = person?.department?.head?.name ?: ""
+val nonNullDepartmentHead: String = person?.department?.head?.name.orEmpty()
+```
+
+### Safe Casts
+```kotlin
+// Will not throw ClassCastException
+val nullableCar: Car? = (input as? Car)
+```
+
+Collections
+-----------
+{: .-two-column}
+
+### Creation
+
+```kotlin
+val numArray = arrayOf(1, 2, 3)
+val numList = listOf(1, 2, 3)
+val mutableNumList = mutableListOf(1, 2, 3)
+```
+
+### Accessing
+
+```kotlin
+val firstItem = numList[0]
+val firstItem = numList.first()
+val firstItem = numList.firstOrNull()
+```
+
+### Maps
+
+```kotlin
+val faceCards = mutableMapOf("Jack" to 11, "Queen" to 12, "King" to 13)
+val jackValue = faceCards["Jack"] // 11
+faceCards["Ace"] = 1
+```
+
+### Mutability
+
+```kotlin
+val immutableList = listOf(1, 2, 3)
+val mutableList = immutableList.toMutableList()
+
+val immutableMap = mapOf("Jack" to 11, "Queen" to 12, "King" to 13)
+val mutableMap = immutableMap.toMutableMap()
+```
+
+### Iterating
+
+```kotlin
+for (item in myList) {
+    print(item)
+}
+
+myList.forEach {
+    print(it)
+}
+
+myList.forEachIndexed { index, item -> 
+    print("Item at $index is: $item")
+}
+```
+
+### Filtering & Searching
+
+```kotlin
+val evenNumbers = numList.filter { it % 2 == 0 }
+val containsEven = numList.any { it % 2 == 0 }
+val containsNoEvens = numList.none { it % 2 == 0 }
+val containsNoEvens = numList.all { it % 2 == 1 }
+val firstEvenNumber: Int = numList.first { it % 2 == 0 }
+val firstEvenOrNull: Int? = numList.firstOrNull { it % 2 == 0 }
+```
+
+Note: `it` is the [implicit name for a single parameter](https://kotlinlang.org/docs/reference/lambdas.html#it-implicit-name-of-a-single-parameter).
+
+Functions
+---------
+{: .-two-column}
+
+### Parameters & Return Types
+
+```kotlin
+fun printName() {
+    print("Adam")
+}
+
+fun printName(person: Person) {
+    print(person.name)
+}
+
+fun getGreeting(person: Person): String {
+    return "Hello, ${person.name}"
+}
+
+fun getGreeting(person: Person): String = "Hello, ${person.name}"
+fun getGreeting(person: Person) = "Hello, ${person.name}"
+```
+
+### Higher Order Functions
+
+```kotlin
+fun callbackIfTrue(condition: Boolean, callback: () -> Unit) {
+    if (condition) {
+        callback()
+    }
+}
+
+callbackIfTrue(someBoolean) {
+    print("Condition was true")
+}
+```
+
+### Extension Functions
+
+```kotlin
+fun Int.timesTwo(): Int {
+    return this * 2
+}
+
+val four = 2.timesTwo()
+```
+
+### Default Parameters
+
+```kotlin
+fun getGreeting(person: Person, intro: String = "Hello,") {
+    return "$intro ${person.name}"
+}
+
+// Returns "Hello, Adam"
+val hello = getGreeting(Person("Adam"))
+
+// Returns "Welcome, Adam"
+val welcome = getGreeting(Person("Adam"), "Welcome,")
+```
+
+### Named Parameters
+
+```kotlin
+class Person(val name: String = "", age: Int = 0)
+
+// All valid
+val person = Person()
+val person = Person("Adam", 100)
+val person = Person(name = "Adam", age = 100)
+val person = Person(age = 100)
+val person = Person(age = 100, name = "Adam")
+```
+
+### Static Functions
+
+```kotlin
+class Fragment(val args: Bundle) {
+    companion object {
+        fun newInstance(args: Bundle): Fragment {
+            return Fragment(args)
+        }
+    }
+}
+
+val fragment = Fragment.newInstance(args)
+```
+
+* [Companion Objects](https://kotlinlang.org/docs/reference/object-declarations.html#companion-objects)
+
+Classes
+-------
+{: .-two-column}
+
+### Primary Constructor
+
+```kotlin
+class Person(val name: String, val age: Int)
+val adam = Person("Adam", 100)
+```
+
+### Secondary Constructors
+
+```kotlin
+class Person(val name: String) {
+    private var age: Int? = null
+
+    constructor(name: String, age: Int) : this(name) {
+        this.age = age
+    }
+}
+
+// Above can be replaced with default params
+class Person(val name: String, val age: Int? = null)
+```
+
+### Inheritance & Implementation
+
+```kotlin
+open class Vehicle
+class Car : Vehicle()
+
+interface Runner {
+    fun run()
+}
+
+class Machine : Runner {
+    override fun run() {
+        // ...
+    }
+}
+```
+
+Control Flow
+------------
+{: .-two-column}
+
+### If Statements
+
+```kotlin
+if (someBoolean) {
+    doThing()
+} else {
+    doOtherThing()
+}
+```
+
+### For Loops
+
+```kotlin
+for (i in 0..10) { } // 1 - 10
+for (i in 0 until 10) // 1 - 9
+(0..10).forEach { }
+for (i in 0 until 10 step 2) // 0, 2, 4, 6, 8
+```
+
+### When Statements
+
+```kotlin
+when (direction) {
+    NORTH -> {
+        print("North")
+    }
+    SOUTH -> print("South")
+    EAST, WEST -> print("East or West")
+    "N/A" -> print("Unavailable")
+    else -> print("Invalid Direction")
+}
+```
+
+### While Loops
+
+```kotlin
+while (x > 0) {
+    x--
+}
+
+do {
+    x--
+} while (x > 0)
+```
+
+Destructuring Declarations
+--------------------------
+{: .-two-column}
+
+### Objects & Lists
+
+```kotlin
+val person = Person("Adam", 100)
+val (name, age) = person
+
+val pair = Pair(1, 2)
+val (first, second) = pair
+
+val coordinates = arrayOf(1, 2, 3)
+val (x, y, z) = coordinates
+```
+
+### ComponentN Functions
+
+```kotlin
+class Person(val name: String, val age: Int) {
+	operator fun component1(): String {
+		return name
+	}
+
+	operator fun component2(): Int {
+		return age
+	}
+}
+```
+
+References
+----------
+{: .-one-column}
+
+* [Defining Variables](https://kotlinlang.org/docs/reference/basic-syntax.html#defining-variables) _(kotlinlang.org)_
+* [Strings Documentation](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html) _(kotlinlang.org)_
+* [String Templates](https://kotlinlang.org/docs/reference/basic-types.html#string-templates) _(kotlinlang.org)_
+* [Basic Types](https://kotlinlang.org/docs/reference/basic-types.html) _(kotlinlang.org)_
+* [Companion Objects](https://kotlinlang.org/docs/reference/object-declarations.html#companion-objects) _(kotlinlang.org)_
+* [Null Safety](https://kotlinlang.org/docs/reference/null-safety.html) _(kotlinlang.org)_
+* [Collections Overview](https://kotlinlang.org/docs/reference/collections.html) _(kotlinlang.org)_
+* [Collections Documentation](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/index.html) _(kotlinlang.org)_
+* [Functions Documentation](https://kotlinlang.org/docs/reference/functions.html) _(kotlinlang.org)_
+* [Classes Documentation](https://kotlinlang.org/docs/reference/classes.html) _(kotlinlang.org)_
+* [Destructuring Declarations](https://kotlinlang.org/docs/reference/multi-declarations.html) _(kotlinlang.org)_

lua.md

@@ -32,7 +32,7 @@ title: Lua
 
     -- Remember, arrays are also tables
     array = { "a", "b", "c", "d" }
-    print(array[2])       -- "b" (zero-indexed)
+    print(array[2])       -- "b" (one-indexed)
     print(#array)         -- 4 (length)
 
 ## Loops

makefile.md

@@ -1,7 +1,8 @@
 ---
 title: Makefile
-hljs_languages: [makefile]
+prism_languages: [makefile]
 layout: 2017/sheet
+category: CLI
 ---
 
 ## Var assignment

markdown.md

@@ -14,6 +14,7 @@ weight: -1
 
 ```markdown
 # h1
+## h2
 ### h3
 ```
 
@@ -43,6 +44,18 @@ __bold__
 `code`
 ```
 
+### Lists
+
+```markdown
+* Item 1
+* Item 2
+```
+
+```markdown
+- Item 1
+- Item 2
+```
+
 ### Links
 
 ```markdown
@@ -109,3 +122,17 @@ codeFences.withLanguage()
 ```markdown
 ****
 ```
+
+### Tables
+
+```markdown
+| Column 1 Heading | Column 2 Heading |
+| ---------------- | ---------------- |
+| Some content     | Other content    |
+```
+
+```markdown
+Column 1 Heading | Column 2 Heading
+--- | ---
+Some content | Other content
+```

moment.md

@@ -9,19 +9,20 @@ tags: [Featurable]
 ### Parsing
 
 ```js
-m = moment("2013-03-01", "YYYY-MM-DD")
+m = moment('2013-03-01', 'YYYY-MM-DD')
 ```
 
 This parses the given date using the given format. Returns a moment object.
+
 ### Formatting
 
 ```js
 m
   .format()
   .format('dddd')
-  .format("MMM Do YY")  // → "Sep 2nd 07"
+  .format('MMM Do YY') // → "Sep 2nd 07"
-  .fromNow()            // → "31 minutes ago"
+  .fromNow() // → "31 minutes ago"
-  .calendar()           // → "Last Friday at 9:32PM"
+  .calendar() // → "Last Friday at 9:32PM"
 ```
 
 ### Add
@@ -56,6 +57,12 @@ See [datetime](./datetime) for more.
 
 ## References
 
- * [Datetime cheatsheet](./datetime) _(devhints.io)_
+### Alternatives
- * [Moment website](http://momentjs.com/) _(momentjs.com)_
+
- * [Moment docs](http://momentjs.com/docs/) _(momentjs.com)_
+* [You don't need Moment.js](https://github.com/you-dont-need/You-Dont-Need-Momentjs) _(github.com)_
+
+### Also see
+
+* [Datetime cheatsheet](./datetime) _(devhints.io)_
+* [Moment website](http://momentjs.com/) _(momentjs.com)_
+* [Moment docs](http://momentjs.com/docs/) _(momentjs.com)_

mysql.md

@@ -0,0 +1,163 @@
+---
+title: MySql
+category: Databases
+---
+### Create / Delete Database
+    CREATE DATABASE dbNameYouWant
+    CREATE DATABASE dbNameYouWant CHARACTER SET utf8
+    DROP DATABASE dbNameYouWant
+    ALTER DATABASE dbNameYouWant CHARACTER SET utf8
+    
+### Backup Database to SQL File
+    mysqldump -u Username -p dbNameYouWant > databasename_backup.sql
+    
+### Restore from backup SQL File
+    mysql - u Username -p dbNameYouWant < databasename_backup.sql
+    
+### Repair Tables After Unclean Shutdown
+    mysqlcheck --all-databases
+    mysqlcheck --all-databases --fast
+### Browsing
+    SHOW DATABASES
+    SHOW TABLES
+    SHOW FIELDS FROM table / DESCRIBE table
+    SHOW CREATE TABLE table
+    SHOW PROCESSLIST
+    KILL process_number
+    
+### Select
+    SELECT * FROM table
+    SELECT * FROM table1, table2, ...
+    SELECT field1, field2, ... FROM table1, table2, ...
+    SELECT ... FROM ... WHERE condition
+    SELECT ... FROM ... WHERE condition GROUPBY field
+    SELECT ... FROM ... WHERE condition GROUPBY field HAVING condition2
+    SELECT ... FROM ... WHERE condition ORDER BY field1, field2
+    SELECT ... FROM ... WHERE condition ORDER BY field1, field2 DESC
+    SELECT ... FROM ... WHERE condition LIMIT 10
+    SELECT DISTINCT field1 FROM ...
+    SELECT DISTINCT field1, field2 FROM ...
+    
+### Select - Join
+    SELECT ... FROM t1 JOIN t2 ON t1.id1 = t2.id2 WHERE condition
+    SELECT ... FROM t1 LEFT JOIN t2 ON t1.id1 = t2.id2 WHERE condition
+    SELECT ... FROM t1 JOIN (t2 JOIN t3 ON ...) ON ...
+
+### Conditions
+    field1 = value1
+    field1 <> value1
+    field1 LIKE 'value _ %'
+    field1 IS NULL
+    field1 IS NOT NULL
+    field1 IS IN (value1, value2)
+    field1 IS NOT IN (value1, value2)
+    condition1 AND condition2
+    condition1 OR condition2
+    
+### Insert    
+    INSERT INTO table1 (field1, field2, ...) VALUES (value1, value2, ...)
+    
+### Delete
+    DELETE FROM table1 / TRUNCATE table1
+    DELETE FROM table1 WHERE condition
+    DELETE FROM table1, table2 FROM table1, table2 WHERE table1.id1 =
+    table2.id2 AND condition
+    
+### Update
+    
+    UPDATE table1 SET field1=new_value1 WHERE condition
+    UPDATE table1, table2 SET field1=new_value1, field2=new_value2, ... WHERE
+    table1.id1 = table2.id2 AND condition
+    
+### Create / Delete / Modify Table
+    
+    *Create*
+    CREATE TABLE table (field1 type1, field2 type2, ...)
+    CREATE TABLE table (field1 type1, field2 type2, ..., INDEX (field))
+    CREATE TABLE table (field1 type1, field2 type2, ..., PRIMARY KEY (field1))
+    CREATE TABLE table (field1 type1, field2 type2, ..., PRIMARY KEY (field1,
+    field2))
+        
+    CREATE TABLE table1 (fk_field1 type1, field2 type2, ...,
+      FOREIGN KEY (fk_field1) REFERENCES table2 (t2_fieldA))
+        [ON UPDATE|ON DELETE] [CASCADE|SET NULL]
+      
+    CREATE TABLE table1 (fk_field1 type1, fk_field2 type2, ...,
+     FOREIGN KEY (fk_field1, fk_field2) REFERENCES table2 (t2_fieldA, t2_fieldB))
+      
+    CREATE TABLE table IF NOT EXISTS (...)
+      
+    CREATE TEMPORARY TABLE table (...)
+      
+    *Drop*
+    DROP TABLE table
+    DROP TABLE IF EXISTS table
+    DROP TABLE table1, table2, ...
+      
+    *Alter*
+    ALTER TABLE table MODIFY field1 type1
+    ALTER TABLE table MODIFY field1 type1 NOT NULL ...
+    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1
+    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1 NOT NULL ...
+    ALTER TABLE table ALTER field1 SET DEFAULT ...
+    ALTER TABLE table ALTER field1 DROP DEFAULT
+    ALTER TABLE table ADD new_name_field1 type1
+    ALTER TABLE table ADD new_name_field1 type1 FIRST
+    ALTER TABLE table ADD new_name_field1 type1 AFTER another_field
+    ALTER TABLE table DROP field1
+    ALTER TABLE table ADD INDEX (field);
+      
+    *Change field order*
+    ALTER TABLE table MODIFY field1 type1 FIRST
+    ALTER TABLE table MODIFY field1 type1 AFTER another_field
+    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1 FIRST
+    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1 AFTER
+    another_field
+    
+### Keys  
+    CREATE TABLE table (..., PRIMARY KEY (field1, field2))
+    CREATE TABLE table (..., FOREIGN KEY (field1, field2) REFERENCES table2
+    (t2_field1, t2_field2))
+    
+    
+### Users and Privileges
+    GRANT ALL PRIVILEGES ON base.* TO 'user'@'localhost' IDENTIFIED BY 'password';
+    GRANT SELECT, INSERT, DELETE ON base.* TO 'user'@'localhost' IDENTIFIED BY 'password';
+    REVOKE ALL PRIVILEGES ON base.* FROM 'user'@'host'; -- one permission only
+    REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'user'@'host'; -- all permissions
+      
+    SET PASSWORD = PASSWORD('new_pass')
+    SET PASSWORD FOR 'user'@'host' = PASSWORD('new_pass')
+    SET PASSWORD = OLD_PASSWORD('new_pass')
+      
+    DROP USER 'user'@'host'
+    host ‘%’ indicates any host.
+    
+    
+### Main Data Types
+     TINYINT (1o: -217+128) SMALLINT (2o: +-65 000)
+     MEDIUMINT (3o: +-16 000 000) INT (4o: +- 2 000 000 000)
+     BIGINT (8o: +-9.10^18)
+     
+     Precise interval: -(2^(8*N-1)) -> (2^8*N)-1
+     /!\ INT(2) = "2 digits displayed" -- NOT "number with 2 digits max"
+      
+     FLOAT(M,D) DOUBLE(M,D) FLOAT(D=0->53)
+     /!\ 8,3 -> 12345,678 -- NOT 12345678,123!
+      
+     TIME (HH:MM) YEAR (AAAA) DATE (AAAA-MM-JJ) DATETIME (AAAA-MM-JJ HH:MM; années 1000->9999)
+     TIMESTAMP (like DATETIME, but 1970->2038, compatible with Unix)
+     
+     VARCHAR (single-line; explicit size) TEXT (multi-lines; max size=65535) BLOB (binary; max size=65535)
+     Variants for TEXT&BLOB: TINY (max=255) MEDIUM (max=~16000) LONG (max=4Go)
+     Ex: VARCHAR(32), TINYTEXT, LONGBLOB, MEDIUMTEXT
+     
+     ENUM ('value1', 'value2', ...) -- (default NULL, or '' if NOT NULL)
+    
+### Reset Root Password
+    $ /etc/init.d/mysql stop
+    $ mysqld_safe --skip-grant-tables
+    $ mysql # on another terminal
+    mysql> UPDATE mysql.user SET password=PASSWORD('new_pass') WHERE user='root';
+    ## Switch back to the mysqld_safe terminal and kill the process using Control + \
+    $ /etc/init.d/mysql start</code>

osx.md

@@ -1,6 +1,7 @@
 ---
 title: OS X
 layout: 2017/sheet
+category: macOS
 ---
 
 ### Locations of startup items

parsley.md

@@ -3,6 +3,7 @@ title: Parsley.js
 updated: 2017-10-19
 weight: -1
 layout: 2017/sheet
+category: JavaScript libraries
 keywords:
   - "data-parsley-validate"
   - "$('#form').parsley()"

polyfill.io.md

@@ -14,26 +14,22 @@ intro: |
 ```html
 <script src="https://cdn.polyfill.io/v2/polyfill.min.js"></script>
 ```
+
 {: .-wrap}
 
 This is the default script for Polyfill.io.
 
 ### References
 
-- [API example](https://polyfill.io/v2/docs/api) _(polyfill.io)_
+* [API example](https://polyfill.io/v2/docs/api) _(polyfill.io)_
-- [List of features](https://polyfill.io/v2/docs/features) _(polyfill.io)_
+* [List of features](https://polyfill.io/v2/docs/features) _(polyfill.io)_
 
 ## Optimized
 
 ### For modern browsers
 
 ```html
-<script>(function(d,s){
+<script>if(!(window.Promise&&[].includes&&Object.assign&&window.Map)){document.write('<script src="https://cdn.polyfill.io/v2/polyfill.min.js"></scr'+'ipt>')}</script>
-if(window.Promise&&[].includes&&Object.assign&&window.Map)return;
-var sc=d.getElementsByTagName(s)[0],js=d.createElement(s);
-js.src='https://cdn.polyfill.io/v2/polyfill.min.js';
-sc.parentNode.insertBefore(js, sc);
-}(document,'script'))</script>
 ```
 
 This only includes polyfill.io when necessary, skipping it for modern browsers for faster load times.
@@ -41,13 +37,7 @@ This only includes polyfill.io when necessary, skipping it for modern browsers f
 ### Extra features
 
 ```html
-<script>(function(d,s){
+<script>if(!(window.fetch&&window.Promise&&[].includes&&Object.assign&&window.Map)){document.write('<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=default,fetch"></scr'+'ipt>')}</script>
-if(window.fetch&&window.Promise&&[].includes&&Object.assign&&window.Map)return;
-var sc=d.getElementsByTagName(s)[0],js=d.createElement(s);
-js.src='https://cdn.polyfill.io/v2/polyfill.min.js?features=default,fetch';
-sc.parentNode.insertBefore(js, sc);
-}(document,'script'))</script>
 ```
-{: data-line="2,4"}
 
 This is the same as the previous, but also adds a polyfill for `window.fetch()`. We add a `window.fetch` check and loads the additional `fetch` feature.

postgresql-json.md

@@ -3,6 +3,7 @@ title: PostgreSQL JSON
 layout: 2017/sheet
 prism_languages: [sql]
 updated: 2017-09-22
+category: Databases
 ---
 
 ## Operators

postgresql.md

@@ -1,5 +1,6 @@
 ---
 title: PostgreSQL
+category: Databases
 ---
 
 Replace anything within `<placeholder>` accordingly

python.md

@@ -1,5 +1,6 @@
 ---
 title: Python
+category: Python
 ---
 
 ### Lists
@@ -15,19 +16,19 @@ title: Python
 
     list.append(item)
     list.extend(another_list)
-    list.insert(0, item)
+    list.insert(index, item)
     list.pop()        # returns and removes last element from the list
-    list.remove(i)
+    list.pop(i)       # returns and removes i-th element from the list
+    list.remove(i)    # removes the first item from the list whose value is i
     list1 + list2     # combine two list    
     set(list)         # remove duplicate elements from a list
 
-    list.reverse()
+    list.reverse()    # reverses the elements of the list in-place
     list.count(item)
     sum(list)
 
+    zip(list1, list2)  # returns list of tuples with n-th element of both list1 and list2
     list.sort()        # sorts in-place, returns None
-
-    zip(list1, list2)
     sorted(list)       # returns sorted copy of list
     ",".join(list)     # returns a string with list elements seperated by comma
 
@@ -43,9 +44,11 @@ title: Python
 ### Iteration
 
     for item in ["a", "b", "c"]:
-    for i in range(4):     # 0 to 3
+    for i in range(4):        # 0 to 3
-    for i in range(4, 8):  # 4 to 7
+    for i in range(4, 8):     # 4 to 7
+    for i in range(1, 9, 2):  # 1, 3, 5, 7
     for key, val in dict.items():
+    for index, item in enumerate(list):
 
 ### [String](https://docs.python.org/2/library/stdtypes.html#string-methods)
 
@@ -76,6 +79,7 @@ title: Python
     float(str)
     str(int)
     str(float)
+    'string'.encode()
 
 ### Comprehensions
 

react.md

@@ -4,7 +4,7 @@ category: React
 layout: 2017/sheet
 ads: true
 tags: [Featured]
-updated: 2017-10-10
+updated: 2018-10-04
 weight: -10
 keywords:
   - React.Component
@@ -48,20 +48,36 @@ ReactDOM.render(<Hello name='John' />, el)
 
 Use the [React.js jsfiddle](http://jsfiddle.net/reactjs/69z2wepo/) to start hacking. (or the unofficial [jsbin](http://jsbin.com/yafixat/edit?js,output))
 
+### Import multiple exports
+{: .-prime}
+
+```jsx
+import React, {Component} from 'react'
+import ReactDOM from 'react-dom'
+```
+{: .-setup}
+
+```jsx
+class Hello extends Component {
+  ...
+}
+```
+
 ### Properties
 
 ```html
-<Video fullscreen={true} />
+<Video fullscreen={true} autoplay={false} />
 ```
 {: .-setup}
 
 ```jsx
 render () {
   this.props.fullscreen
+  const { fullscreen, autoplay } = this.props
   ···
 }
 ```
-{: data-line="2"}
+{: data-line="2,3"}
 
 Use `this.props` to access properties passed to the component.
 
@@ -72,7 +88,7 @@ See: [Properties](https://reactjs.org/docs/tutorial.html#using-props)
 ```jsx
 constructor(props) {
   super(props)
-  this.state = {}
+  this.state = { username: undefined }
 }
 ```
 
@@ -83,19 +99,30 @@ this.setState({ username: 'rstacruz' })
 ```jsx
 render () {
   this.state.username
+  const { username } = this.state
   ···
 }
 ```
-{: data-line="2"}
+{: data-line="2,3"}
 
 Use states (`this.state`) to manage dynamic data.
 
+With [Babel](https://babeljs.io/) you can use [proposal-class-fields](https://github.com/tc39/proposal-class-fields) and get rid of constructor
+
+```jsx
+class Hello extends Component {
+  state = { username: undefined };
+  ...
+}
+```
+
 See: [States](https://reactjs.org/docs/tutorial.html#reactive-state)
 
+
 ### Nesting
 
 ```jsx
-class Info extends React.Component {
+class Info extends Component {
   render () {
     const { avatar, username } = this.props
 
@@ -109,15 +136,20 @@ class Info extends React.Component {
 As of React v16.2.0, fragments can be used to return multiple children without adding extra wrapping nodes to the DOM.
 
 ```jsx
-class Info extends React.Component {
+import React, {
+  Component,
+  Fragment
+} from 'react'
+
+class Info extends Component {
   render () {
     const { avatar, username } = this.props
 
     return (
-      <React.Fragment>
+      <Fragment>
         <UserAvatar src={avatar} />
         <UserProfile username={username} />
-      </React.Fragment>
+      </Fragment>
     )
   }
 }
@@ -140,7 +172,7 @@ See: [Composing Components](https://reactjs.org/docs/components-and-props.html#c
 {: data-line="2"}
 
 ```jsx
-class AlertBox extends React.Component {
+class AlertBox extends Component {
   render () {
     return <div className='alert-box'>
       {this.props.children}
@@ -169,7 +201,7 @@ See: [defaultProps](https://reactjs.org/docs/react-component.html#defaultprops)
 ### Setting default state
 
 ```jsx
-class Hello extends React.Component {
+class Hello extends Component {
   constructor (props) {
     super(props)
     this.state = { visible: true }
@@ -180,13 +212,24 @@ class Hello extends React.Component {
 
 Set the default state in the `constructor()`.
 
+And without constructor using [Babel](https://babeljs.io/) with [proposal-class-fields](https://github.com/tc39/proposal-class-fields).
+
+```jsx
+class Hello extends Component {
+    state = { visible: true }
+  }
+}
+```
+
+{: data-line="2"}
+
 See: [Setting the default state](https://reactjs.org/docs/react-without-es6.html#setting-the-initial-state)
 
 Other components
 ----------------
 {: .-three-column}
 
-### Function components
+### Functional components
 
 ```jsx
 function MyComponent ({ name }) {
@@ -204,11 +247,13 @@ See: [Function and Class Components](https://reactjs.org/docs/components-and-pro
 ### Pure components
 
 ```jsx
-class MessageBox extends React.PureComponent {
+import React, {PureComponent} from 'react'
+
+class MessageBox extends PureComponent {
   ···
 }
 ```
-{: data-line="1"}
+{: data-line="3"}
 
 Performance-optimized version of `React.Component`. Doesn't rerender if props/state hasn't changed.
 
@@ -222,6 +267,7 @@ this.forceUpdate()
 
 ```jsx
 this.setState({ ... })
+this.setState(state => { ... })
 ```
 
 ```jsx
@@ -257,9 +303,8 @@ Add DOM event handlers, timers (etc) on `componentDidMount()`, then remove them
 
 | Method | Description |
 | --- | --- |
-| `componentWillReceiveProps` *(newProps)* | Use `setState()` here |
+| `componentDidUpdate` *(prevProps, prevState, snapshot)* | Use `setState()` here, but remember to compare props |
 | `shouldComponentUpdate` *(newProps, newState)* | Skips `render()` if returns false |
-| `componentWillUpdate` *(newProps, newState)* | Can't use `setState()` here |
 | `render()` | Render |
 | `componentDidUpdate` *(prevProps, prevState)* | Operate on the DOM here |
 
@@ -274,7 +319,7 @@ DOM nodes
 ### References
 
 ```jsx
-class MyComponent extends React.Component {
+class MyComponent extends Component {
   render () {
     return <div>
       <input ref={el => this.input = el} />
@@ -295,7 +340,7 @@ See: [Refs and the DOM](https://reactjs.org/docs/refs-and-the-dom.html)
 ### DOM Events
 
 ```jsx
-class MyComponent extends React.Component {
+class MyComponent extends Component {
   render () {
     <input type="text"
         value={this.state.value}
@@ -323,7 +368,7 @@ See: [Events](https://reactjs.org/docs/events.html)
 {: .-setup}
 
 ```jsx
-class VideoPlayer extends React.Component {
+class VideoPlayer extends Component {
   render () {
     return <VideoEmbed {...this.props} />
   }
@@ -363,7 +408,7 @@ JSX patterns
 ### Style shorthand
 
 ```jsx
-var style = { height: 10 }
+const style = { height: 10 }
 return <div style={style}></div>
 ```
 
@@ -385,7 +430,7 @@ See: [Dangerously set innerHTML](https://reactjs.org/tips/dangerously-set-inner-
 ### Lists
 
 ```jsx
-class TodoList extends React.Component {
+class TodoList extends Component {
   render () {
     const { items } = this.props
 
@@ -403,19 +448,20 @@ Always supply a `key` property.
 ### Conditionals
 
 ```jsx
-<div>
+<Fragment>
   {showMyComponent
     ? <MyComponent />
     : <OtherComponent />}
-</div>
+</Fragment>
 ```
 
 ### Short-circuit evaluation
 
 ```jsx
-<div>
+<Fragment>
   {showPopup && <Popup />}
-</div>
+  ...
+</Fragment>
 ```
 
 New features
@@ -444,10 +490,10 @@ render () {
 render () {
   // Fragments don't require keys!
   return (
-    <React.Fragment>
+    <Fragment>
       <li>First item</li>
       <li>Second item</li>
-    </React.Fragment>
+    </Fragment>
   )
 }
 ```
@@ -471,7 +517,7 @@ See: [Fragments and strings](https://reactjs.org/blog/2017/09/26/react-v16.0.htm
 ### Errors
 
 ```js
-class MyComponent extends React.Component {
+class MyComponent extends Component {
   ···
   componentDidCatch (error, info) {
     this.setState({ error })

regexp.md

@@ -1,12 +1,59 @@
 ---
-title: Regexp
+title: regexp
+category: Others
+layout: 2017/sheet
+weight: -1
+authors:
+  - github: rizqyhi
+updated: 2018-10-26
+description: |
+  Basic cheatsheets for regular expression
 ---
 
-    (?P<named_match>...)
+### Character Classes
-    (?:invisible group)
 
-    (?!negative look-ahead)
+| Pattern | Description |
-    (?=positive look-ahead)
+| ---     | --- |
-    (?<!negative look-behind)
+| `.`     | Any character, except newline |
-    (?<=positive look-behind)
+| `\w`    | Word |
+| `\d`    | Digit |
+| `\s`    | Whitespace |
+| `\W`    | Not word |
+| `\d`    | Not digit |
+| `\S`    | Not whitespace |
+| `[abc]` | Any of a, b, or c |
+| `[a-e]` | Characters between `a` and `e` |
+| `[1-9]` | Digit between `1` and `9` |
 
+### Anchors
+
+| Pattern | Description |
+| ---     | --- |
+| `^abc` | Start with `abc` |
+| `abc$` | End with `abc` |
+
+### Escaped Characters
+
+| Pattern | Description |
+| ---        | --- |
+| `\. \* \\` | Escape special character used by regex |
+| `\t`       | Tab |
+| `\n`       | Newline |
+| `\r`       | Carriage return |
+
+### Groups
+
+| Pattern | Description |
+| ---     | --- |
+| `(abc)` | Capture group |
+
+### Quantifiers
+
+| Pattern  | Description |
+| ---      | --- |
+| `a*`     | Match 0 or more |
+| `a+`     | Match 1 or more |
+| `a?`     | Match 0 or 1 |
+| `a{5}`   | Match exactly 5 |
+| `a{3,}`  | Match 3 or more |
+| `a{1,3}` | Match between 1 and 3 |

rsync.md

@@ -9,7 +9,10 @@ weight: -1
 {: .-prime}
 
 ```bash
+# syncing folder src into dest:
 rsync -avz ./src /dest
+# syncing the content of src into dest:
+rsync -avz ./src/ /dest
 ```
 
 ### OSX
@@ -25,6 +28,7 @@ rsync -avz ./src /dest
 ```bash
 -z, --compress
 -n, --dry-run
+    --partial   # allows resuming of aborted syncs
 ```
 
 ### Display options
@@ -34,6 +38,7 @@ rsync -avz ./src /dest
 -v, --verbose
 -h, --human-readable
     --progress
+-P                     # same as --partial --progress
 ```
 
 ### Skipping options
@@ -61,7 +66,7 @@ rsync -avz ./src /dest
 ```bash
 --exclude-from=FILE
 --include-from=FILE
---files-from=FILE    # read list of filenames from FILe
+--files-from=FILE    # read list of filenames from FILE
 ```
 
 ### Archive options

sass.md

@@ -66,7 +66,7 @@ h1 {
 }
 ```
 
-### Mixin properties
+#### with parameters
 
 ```scss
 @mixin font-size($n) {
@@ -80,6 +80,39 @@ body {
 }
 ```
 
+#### with default values
+
+```scss
+@mixin pad($n: 10px) {
+  padding: $n;
+}
+```
+
+```scss
+body {
+  @include pad(15px);
+}
+```
+
+#### with a default variable
+
+```scss
+// Set a default value
+$default-padding: 10px;
+```
+
+```scss
+@mixin pad($n: $default-padding) {
+  padding: $n;
+}
+```
+
+```scss
+body {
+  @include pad(15px);
+}
+```
+
 ### Extend
 
 ```scss
@@ -133,7 +166,7 @@ grayscale($color)
 
 ```scss
 adjust-hue($color, 15deg)
-compliment($color)    // like adjust-hue(_, 180deg)
+complement($color)    // like adjust-hue(_, 180deg)
 invert($color)
 ```
 

semver.md

@@ -1,7 +1,7 @@
 ---
 title: Semver
 layout: 2017/sheet
-updated: 2018-01-15
+updated: 2018-08-23
 weight: -3
 ---
 
@@ -93,4 +93,4 @@ When the left is partial (eg, `1.2`), missing pieces are assumed to be `0` (eg,
 {: .-one-column}
 
  * <http://semver.org/>
- * <https://www.npmjs.org/doc/misc/semver.html>
+ * <https://docs.npmjs.com/misc/semver>

sql-join.md

@@ -1,6 +1,7 @@
 ---
 title: SQL joins
 layout: 2017/sheet
+category: Databases
 updated: 2017-10-30
 weight: -1
 ---

tig.md

@@ -42,6 +42,7 @@ You can substitute `git log` → `tig`.
 | `m` | Main view |
 | `s` | Status |
 | `t` | Tree (files) |
+| `y` | Stash view |
 | `g` | Grep |
 | `h` | Help |
 {: .-shortcuts}

tmux.md

@@ -1,5 +1,6 @@
 ---
 title: tmux
+category: CLI
 ---
 
 ### Commands
@@ -8,7 +9,23 @@ title: tmux
       -u        # UTF8 mode
       -S ~/.tmux.socket
 
-    $ tmux attach
+#### Sessions
+
+    $ tmux new
+    $ tmux new -s session_name
+
+    $ tmux attach # Default session
+    $ tmux attach -s session_name
+
+    $ tmux switch -t session_name
+
+    $ tmux ls     # List sessions
+
+    $ tmux detach
+
+#### Windows
+
+    $ tmux new-window
 
 ### Help
 

travis.md

@@ -1,5 +1,6 @@
 ---
 title: Travis.yml
+category: Devops
 ---
 
 ### Node

umdjs.md

@@ -1,5 +1,6 @@
 ---
 title: Universal JS module loader
+category: JavaScript libraries
 ---
 
 ### [With dependency](https://github.com/umdjs/umd/blob/master/amdWebGlobal.js)

vim-diff.md

@@ -0,0 +1,60 @@
+---
+title: Vimdiff
+category: Vim
+layout: 2017/sheet
+updated: 2017-08-26
+weight: -10
+intro: |
+  [Vim](http://www.vim.org/) is a very efficient text editor. This reference was made for Vim 8.0.
+---
+
+Getting started
+---------------
+{: .-three-column}
+
+### Navigating
+{: .-prime}
+
+| Shortcut       | Description                      |
+| ---            | ---                              |
+| `]c`           | Next difference                  |
+| `[c`           | Previous difference              |
+{: .-shortcuts}
+
+### Editing
+
+| Shortcut | Description                         |
+| ---            | ---                              |
+| `do`           | Diff Obtain! <br>Pull the changes to the current file. |
+| `dp`           | Diff Put! <br>Push the changes to the other file. |
+| ---            | ---                              |
+| `:diffupdate`  | Re-scan the files for differences.                    |
+| `ZQ`           | Quit without checking changes    |
+{: .-shortcuts}
+
+### Folds
+
+| Shortcut      | Description                  |
+| ---           | ---                          |
+| `zo` _/_ `zO` | Open                         |
+| `zc` _/_ `zC` | Close                        |
+| `za` _/_ `zA` | Toggle                       |
+| ---           | ---                          |
+| `zv`          | Open folds for this line     |
+| ---           | ---                          |
+| `zM`          | Close all                    |
+| `zR`          | Open all                     |
+| ---           | ---                          |
+| `zm`          | Fold more _(foldlevel += 1)_ |
+| `zr`          | Fold less _(foldlevel -= 1)_ |
+| ---           | ---                          |
+| `zx`          | Update folds                 |
+{: .-shortcuts}
+
+
+Also see
+--------
+
+- [Vim cheatsheet](https://vim.rtorr.com/) _(vim.rotrr.com)_
+- [Vim documentation](http://vimdoc.sourceforge.net/htmldoc/) _(vimdoc.sourceforge.net)_
+- [Interactive Vim tutorial](http://openvim.com/) _(openvim.com)_

vim.md

@@ -3,10 +3,11 @@ title: Vim
 category: Vim
 layout: 2017/sheet
 tags: [Featured]
-updated: 2017-08-26
+updated: 2018-09-11
 weight: -10
 intro: |
-  [Vim](http://www.vim.org/) is a very efficient text editor. This reference was made for Vim 8.0.
+ [Vim](http://www.vim.org/) is a very efficient text editor. This reference was made for Vim 8.0.   
+ For shortcut notation, see `:help key-notation`.
 ---
 
 Getting started
@@ -33,14 +34,18 @@ Getting started
 
 ### Navigating
 
-| `h` `j` `k` `l`     | Arrow keys                         |
+| Shortcut            | Description       |
-| `<C-U>` _/_ `<C-D>` | Page up/page down                  |
+| ---                 | ---               |
+| `h` `j` `k` `l`     | Arrow keys        |
+| `<C-U>` _/_ `<C-D>` | Page up/page down |
 {: .-shortcuts}
 
 #### Words
 
-| `b` _/_ `w`     | Previous/next word                 |
+| Shortcut     | Description               |
-| `e` _/_ `ge`    | Previous/next end of word          |
+| ---          | ---                       |
+| `b` _/_ `w`  | Previous/next word        |
+| `e` _/_ `ge` | Previous/next end of word |
 {: .-shortcuts}
 
 #### Line
@@ -78,6 +83,18 @@ Getting started
 | `L`      | Move to bottom of screen |
 {: .-shortcuts}
 
+#### Tab pages
+
+| Shortcut              | Description                     |
+| ---                   | ---                             |
+| `:tabedit [file]`     | Edit file in a new tab          |
+| `:tabfind [file]`     | Open file if exists in new tab  |
+| `:tabclose`           | Close current tab               |
+| `:tabs`               | List all tabs                   | 
+| `:tabfirst`           | Go to first tab                 |
+| `:tablast`            | Go to last tab                  |
+| `:tabn    `           | Go to next tab                  |
+| `:tabp    `           | Go to previous tab              |
 
 ### Editing
 
@@ -94,14 +111,17 @@ Getting started
 | ---      | ---                                 |
 | `r`      | Replace one character               |
 | `R`      | Enter Replace mode                  |
+| ---      | ---                                 |
+| `u`      | Undo changes                        |
+| `<C-R>`  | Redo changes                        |
 {: .-shortcuts}
 
 ### Exiting insert mode
 
-| Shortcut | Description |
+| Shortcut          | Description |
-| --- | --- |
+| ---               | ---         |
 | `Esc` _/_ `<C-[>` | Exit insert mode |
-| `<C-C>` | Exit insert mode, and abort current command |
+| `<C-C>`           | Exit insert mode, and abort current command |
 {: .-shortcuts}
 
 ### Clipboard
@@ -119,13 +139,17 @@ Getting started
 
 ### Visual mode
 
-| `v`         | Enter visual mode       |
+| Shortcut | Description             |
-| `V`         | Enter visual line mode  |
+| ---      | ---                     |
-| `<C-V>`        | Enter visual block mode |
+| `v`      | Enter visual mode       |
+| `V`      | Enter visual line mode  |
+| `<C-V>`  | Enter visual block mode |
 {: .-shortcuts}
 
 #### In visual mode
 
+| Shortcut    | Description             |
+| ---         | ---                     |
 | `d` _/_ `x` | Delete selection        |
 | `s`         | Replace selection       |
 | `y`         | Yank selection _(Copy)_ |
@@ -229,6 +253,13 @@ Text objects let you operate (with an *operator*) in or around text blocks (*obj
 
 See [Operators](#operators) for other things you can do.
 
+### Diff
+ 
+| Shortcut                             | Description                              |
+| ---                                  | ---                                      |
+| `gvimdiff file1 file2 [file3]`       | See differencies between files, in HMI   |
+ 
+
 Misc
 ----
 
@@ -257,27 +288,29 @@ Uppercase ones are recursive (eg, `zO` is open recursively).
 
 | Shortcut            | Description                |
 | ---                 | ---                        |
-| `[(` `[{` `[<`      | previous `(` or `{` or `<` |
+| `[(` `[{` `[<`      | Previous `(` or `{` or `<` |
-| `])`                | next                       |
+| `])`                | Next                       |
 | ---                 | ---                        |
-| `[m`                | previous method start      |
+| `[m`                | Previous method start      |
-| `[M`                | previous method end        |
+| `[M`                | Previous method end        |
 {: .-shortcuts}
 
 ### Jumping
 
 | Shortcut | Description                  |
 | ---      | ---                          |
-| `<C-O>`     | Go back to previous location |
+| `<C-O>`  | Go back to previous location |
-| `<C-I>`     | Go forward                   |
+| `<C-I>`  | Go forward                   |
 | ---      | ---                          |
-| `gf`     | go to file in cursor         |
+| `gf`     | Go to file in cursor         |
 {: .-shortcuts}
 
 ### Counters
 
-| `<C-A>` | increment number |
+| Shortcut | Description      |
-| `<C-X>` | decrement |
+| ---      | ---              |
+| `<C-A>`  | Increment number |
+| `<C-X>`  | Decrement        |
 {: .-shortcuts}
 
 ### Windows
@@ -303,12 +336,12 @@ Uppercase ones are recursive (eg, `zO` is open recursively).
 
 | Shortcut | Description                          |
 | ---      | ---                                  |
-| `~`      | toggle case (Case => cASE)           |
+| `~`      | Toggle case (Case => cASE)           |
-| `gU`     | uppercase                            |
+| `gU`     | Uppercase                            |
-| `gu`     | lowercase                            |
+| `gu`     | Lowercase                            |
 | ---      | ---                                  |
-| `gUU`    | uppercase current line (also `gUgU`) |
+| `gUU`    | Uppercase current line (also `gUgU`) |
-| `guu`    | lowercase current line (also `gugu`) |
+| `guu`    | Lowercase current line (also `gugu`) |
 {: .-shortcuts}
 
 Do these in visual or normal mode.
@@ -330,16 +363,17 @@ Do these in visual or normal mode.
 
 | Shortcut | Description                               |
 | ---      | ---                                       |
-| `.`      | repeat last command                       |
+| `.`      | Repeat last command                       |
-| `]p`     | paste under the current indentation level |
+| `]p`     | Paste under the current indentation level |
 {: .-shortcuts}
 
 ### Command line
 
 | Shortcut     | Description                               |
 | ---          | ---                                       |
-| `<C-R><C-W>` | insert current word into the command line |
+| `<C-R><C-W>` | Insert current word into the command line |
-| `<C-R>"`     | paste from " register                     |
+| `<C-R>"`     | Paste from " register                     |
+| `<C-X><C-F>` | Auto-completion of path in insert mode    |
 {: .-shortcuts}
 
 ### Text alignment
@@ -352,7 +386,9 @@ See `:help formatting`
 
 ### Calculator
 
-    <C-R>=128/2
+| Shortcut      | Description                               |
+| ---           | ---                                       |
+| `<C-R>=128/2` | Shows the result of the division : '64'   |
 
 Do this in insert mode.
 
@@ -363,6 +399,23 @@ Do this in insert mode.
 
 Works like `:qa`, but throws an error. Great for aborting Git commands.
 
+
+### Spell checking
+
+| Shortcut                     | Description                                             |
+| ---                          | ---                                                     |
+| `:set spell spelllang=en_us` | Turn on US English spell checking                       |
+| `]s`                         | Move to next misspelled word after the cursor           |
+| `[s`                         | Move to previous misspelled word before the cursor      |
+| `z=`                         | Suggest spellings for the word under/after the cursor   |
+| `zg`                         | Add word to spell list                                  |
+| `zw`                         | Mark word as bad/mispelling                             |
+| `zu` / `C-X (Insert Mode)`   | Suggest words for bad word under cursor from spellfile  |
+{: .-shortcuts}
+
+See `:help spell`
+
+
 Also see
 --------
 

wip/php.md

@@ -1,6 +1,6 @@
 ---
 title: PHP
-category: Other
+category: PHP
 layout: 2017/sheet
 prism_languages: [php]
 ---
@@ -28,12 +28,22 @@ See: [PHP tags](http://php.net/manual/en/language.basic-syntax.phptags.php)
 ```php
 <?php
 
-$fruits = array(
+$fruitsArray = array(
   "apple" => 20,
   "banana" => 30
-)
+);
+echo $fruitsArray['banana'];
 ```
 
+Or cast as object
+
+```php
+<?php
+
+$fruitsObject = (object) $fruits;
+echo $fruitsObject->banana;
+``` 
+
 ### Inspecting objects
 
 ```php
@@ -44,3 +54,56 @@ var_dump($object)
 Prints the contents of a variable for inspection.
 
 See: [var_dump](http://php.net/var_dump)
+
+### Classes
+
+```php
+class Person {
+    public $name = '';
+}
+
+$person = new Person();
+$person->name = 'bob';
+
+echo $person->name;
+```
+
+### Getters and setters
+
+```php
+class Person 
+{
+    public $name = '';
+
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    public function setName($name)
+    {
+        $this->name = $name;
+        return $this;
+    }
+}
+
+$person = new Person();
+$person->setName('bob');
+
+echo $person->getName();
+```
+
+### isset vs empty
+```php
+
+$options = [
+  'key' => 'value',
+  'blank' => '',
+  'nothing' => null,
+];
+
+var_dump(isset($options['key']), empty($options['key'])); // true, false
+var_dump(isset($options['blank']), empty($options['blank'])); // true, true
+var_dump(isset($options['nothing']), empty($options['nothing'])); // false, true
+
+```

yarn.md

@@ -16,6 +16,7 @@ tags: [Featurable]
 | `npm install gulp --save` | `yarn add gulp` |
 | `npm install gulp --save-dev --save-exact` | `yarn add gulp --dev --exact` |
 | `npm install -g gulp` | `yarn global add gulp` |
+| `npm update` | `yarn upgrade` |
 | `./node_modules/.bin/gulp` | `yarn run gulp` |
 {: .-left-align.-headers}
 

zsh.md

@@ -27,6 +27,14 @@ layout: 2017/sheet
 chsh -s `which zsh`
 ```
 
+### Process Substitution
+
+| Expression        | Example                                               | Description
+| ---               | ---                                                   | ---
+| `<(COMMAND)`      | `grep "needle" <(curl "https://haystack.io")`         | Replace argument with _named pipe/FIFO_ (read-only) with command output
+| `=(COMMAND)`      | `vim =(curl "https://haystack.io")`                   | Replace argument with _file_ (writable) containing command output
+{: .-headers}
+
 ### Also see
 
 - [Bash cheatsheet](./bash)