Updates send_string functionality, adds terminal feature (#1657)

* implement basic terminal stuff

* modify send_string to read normal strings too

* add files bc yeah. working pgm detected

* pgm detection apparently not working

* adds send string keycodes, additional keycode support in send string

* implement arguments

* [terminal] add help command

* [terminal] adds keycode and keymap functions

* [terminal] adds nop.h, documentation

* update macro docs

3 files changed, 176 insertions, 41 deletions

diff --git a/docs/_summary.md b/docs/_summary.md
index 77d208fc3..ce02220fb 100644
--- a/docs/_summary.md
+++ b/docs/_summary.md
@@ -28,6 +28,7 @@
   * [Thermal Printer](feature_thermal_printer.md)
   * [Stenography](stenography.md)
   * [Unicode](unicode.md)
+  * [Terminal](feature_terminal.md)
 
 * Reference
   * [Glossary](glossary.md)
diff --git a/docs/feature_terminal.md b/docs/feature_terminal.md
new file mode 100644
index 000000000..2c5f2c486
--- /dev/null
+++ b/docs/feature_terminal.md
@@ -0,0 +1,80 @@
+# Terminal
+
+> This feature is currently *huge* at 4400 bytes, and should probably only be put on boards with a lot of memory, or for fun.
+
+The terminal feature is a command-line-like interface designed to communicate through a text editor with keystrokes. It's beneficial to turn off auto-indent features in your editor.
+
+To enable, stick this in your `rules.mk` or `Makefile`:
+
+    TERMINAL_ENABLE = yes
+
+And use the `TERM_ON` and `TERM_OFF` keycodes to turn it on or off.
+
+When enabled, a `> ` prompt will appear, where you'll be able to type, backspace (a bell will ding if you reach the beginning and audio is enabled), and hit enter to send the command. Arrow keys are currently disabled so it doesn't get confused. Moving your cursor around with the mouse is discouraged.
+
+`#define TERMINAL_HELP` enables some other output helpers that aren't really needed with this page.
+
+## Future ideas
+
+* Keyboard/user-extendable commands
+* Smaller footprint
+* Arrow key support
+* Command history
+* SD card support
+* LCD support for buffer display
+* Keycode -> name string LUT
+* Layer status
+* *Analog/digital port read/write*
+* RGB mode stuff
+* Macro definitions
+* EEPROM read/write
+* Audio control
+
+## Current commands
+
+### `about`
+
+Prints out the current version of QMK with a build date:
+
+```
+> about
+QMK Firmware
+  v0.5.115-7-g80ed73-dirty
+  Built: 2017-08-29-20:24:44
+```
+
+### `help`
+
+Prints out the available commands:
+
+```
+> help
+commands available:
+  about help keycode keymap exit
+```
+
+### `keycode <layer> <row> <col>`
+
+Prints out the keycode value of a certain layer, row, and column:
+
+```
+> keycode 0 1 0
+0x29 (41)
+```
+
+### `keymap <layer>`
+
+Prints out the entire keymap for a certain layer
+
+```
+> keymap 0
+0x002b, 0x0014, 0x001a, 0x0008, 0x0015, 0x0017, 0x001c, 0x0018, 0x000c, 0x0012, 0x0013, 0x002a, 
+0x0029, 0x0004, 0x0016, 0x0007, 0x0009, 0x000a, 0x000b, 0x000d, 0x000e, 0x000f, 0x0033, 0x0034, 
+0x00e1, 0x001d, 0x001b, 0x0006, 0x0019, 0x0005, 0x0011, 0x0010, 0x0036, 0x0037, 0x0038, 0x0028, 
+0x5cd6, 0x00e0, 0x00e2, 0x00e3, 0x5cd4, 0x002c, 0x002c, 0x5cd5, 0x0050, 0x0051, 0x0052, 0x004f,
+> 
+```
+
+### `exit`
+
+Exits the terminal - same as `TERM_OFF`.
\ No newline at end of file
diff --git a/docs/macros.md b/docs/macros.md
index c7a9b2e7a..66d2bc090 100644
--- a/docs/macros.md
+++ b/docs/macros.md
@@ -1,72 +1,126 @@
 # Macros
 
-Macros allow you to send multiple keystrokes when pressing just one key. QMK has a number of ways to define and use macros. These can do anything you want- type common phrases for you, copypasta, repetitive game movements, or even help you code. 
+Macros allow you to send multiple keystrokes when pressing just one key. QMK has a number of ways to define and use macros. These can do anything you want: type common phrases for you, copypasta, repetitive game movements, or even help you code. 
 
 {% hint style='danger' %}
 **Security Note**: While it is possible to use macros to send passwords, credit card numbers, and other sensitive information it is a supremely bad idea to do so. Anyone who gets ahold of your keyboard will be able to access that information by opening a text editor.
 {% endhint %}
 
-# Macro Definitions
+## The new way: `SEND_STRING()` & `process_record_user`
 
-By default QMK assumes you don't have any macros. To define your macros you create an `action_get_macro()` function. For example:
+Sometimes you just want a key to type out words or phrases. For the most common situations we've provided `SEND_STRING()`, which will type out your string for you. All ascii that is easily translated to a keycode is supported (eg `\n\t`).
+
+For example:
 
 ```c
-const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) {
+enum custom_keycodes {
+	PRINT_TRUTH = SAFE_RANGE
+};
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
 	if (record->event.pressed) {
-		switch(id) {
-			case 0:
-				return MACRO(D(LSFT), T(H), U(LSFT), T(I), D(LSFT), T(1), U(LSFT), END);
-			case 1:
-				return MACRO(D(LSFT), T(B), U(LSFT), T(Y), T(E), D(LSFT), T(1), U(LSFT), END);
+		switch(keycode) {
+			case PRINT_TRUTH:
+				SEND_STRING("QMK is the best thing ever!");
+				return false; break;
 		}
 	}
-	return MACRO_NONE;
+	return true;
 };
 ```
 
-This defines two macros which will be run when the key they are assigned to is pressed. If instead you'd like them to run when the key is released you can change the if statement:
+### Tap/down/up
+
+You can send arbitary keycodes by wrapping them in:
+
+* `SS_TAP()`
+* `SS_DOWN()`
+* `SS_UP()`
+
+For example:
+
+    SEND_STRING(SS_TAP(X_HOME));
+
+Would tap `KC_HOME` - note how the prefix is now `X_`, and not `KC_`. You can also combine this with other strings, like this:
+
+    SEND_STRING("VE"SS_TAP(X_HOME)"LO");
+
+Which would send "VE" followed by a `KC_HOME` tap, and "LO" (spelling "LOVE" if on a newline).
+
+There's also a couple of mod shortcuts you can use:
+
+* `SS_LCTRL(string)`
+* `SS_LGUI(string)`
+* `SS_LALT(string)`
+
+That can be used like this:
+
+    SEND_STRING(SS_LCTRL("a"));
+
+Which would send LCTRL+a (LTRL down, a, LTRL up) - notice that they take strings (eg `"k"`), and not the `X_K` keycodes.
+
+### Alternative keymaps
+
+By default, it assumes a US keymap with a QWERTY layout; if you want to change that (e.g. if your OS uses software Colemak), include this somewhere in your keymap:
+
+    #include <sendstring_colemak.h>
+
+### Strings in memory
+
+If for some reason you're manipulating strings and need to print out something you just generated (instead of being a literal, constant string), you can use `send_string()`, like this:
 
 ```c
-	if (!record->event.pressed) {
+char my_str[4] = "ok.";
+send_string(my_str);
 ```
 
-## Macro Commands
-
-A macro can include the following commands:
+The shortcuts defined above won't work with `send_string()`, but you can separate things out to different lines if needed:
 
-* I() change interval of stroke in milliseconds.
-* D() press key.
-* U() release key.
-* T() type key(press and release).
-* W() wait (milliseconds).
-* END end mark.
+```c
+char my_str[4] = "ok.";
+SEND_STRING("I said: ");
+send_string(my_str);
+SEND_STRING(".."SS_TAP(X_END));
+```
 
-## Sending strings
+## The old way: `MACRO()` & `action_get_macro`
 
-Sometimes you just want a key to type out words or phrases. For the most common situations we've provided `SEND_STRING()`, which will type out your string for you instead of having to build a `MACRO()`.
+{% hint style='info' %}
+This is inherited from TMK, and hasn't been updated - it's recommend that you use `SEND_STRING` and `process_record_user` instead.
+{% endhint %}
 
-For example:
+By default QMK assumes you don't have any macros. To define your macros you create an `action_get_macro()` function. For example:
 
 ```c
 const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) {
 	if (record->event.pressed) {
 		switch(id) {
 			case 0:
-				SEND_STRING("QMK is the best thing ever!");
-				return false;
+				return MACRO(D(LSFT), T(H), U(LSFT), T(I), D(LSFT), T(1), U(LSFT), END);
+			case 1:
+				return MACRO(D(LSFT), T(B), U(LSFT), T(Y), T(E), D(LSFT), T(1), U(LSFT), END);
 		}
 	}
 	return MACRO_NONE;
 };
 ```
 
-By default, it assumes a US keymap with a QWERTY layout; if you want to change that (e.g. if your OS uses software Colemak), include this somewhere in your keymap:
+This defines two macros which will be run when the key they are assigned to is pressed. If instead you'd like them to run when the key is released you can change the if statement:
 
-```
-#include <sendstring_colemak.h>
-```
+	if (!record->event.pressed) {
+
+### Macro Commands
+
+A macro can include the following commands:
+
+* I() change interval of stroke in milliseconds.
+* D() press key.
+* U() release key.
+* T() type key(press and release).
+* W() wait (milliseconds).
+* END end mark.
 
-## Mapping a Macro to a key
+### Mapping a Macro to a key
 
 Use the `M()` function within your `KEYMAP()` to call a macro. For example, here is the keymap for a 2-key keyboard:
 
@@ -92,7 +146,7 @@ const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) {
 
 When you press the key on the left it will type "Hi!" and when you press the key on the right it will type "Bye!".
 
-## Naming your macros
+### Naming your macros
 
 If you have a bunch of macros you want to refer to from your keymap while keeping the keymap easily readable you can name them using `#define` at the top of your file.
 
@@ -107,11 +161,11 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 };
 ```
 
-# Advanced macro functions
+## Advanced macro functions
 
-While working within the `action_get_macro()` function block there are some functions you may find useful. Keep in mind that while you can write some fairly advanced code within a macro if your functionality gets too complex you may want to define a custom keycode instead. Macros are meant to be simple.
+There are some functions you may find useful in macro-writing. Keep in mind that while you can write some fairly advanced code within a macro if your functionality gets too complex you may want to define a custom keycode instead. Macros are meant to be simple.
 
-#### `record->event.pressed`
+### `record->event.pressed`
 
 This is a boolean value that can be tested to see if the switch is being pressed or released. An example of this is
 
@@ -123,27 +177,27 @@ This is a boolean value that can be tested to see if the switch is being pressed
 	}
 ```
 
-#### `register_code(<kc>);`
+### `register_code(<kc>);`
 
 This sends the `<kc>` keydown event to the computer. Some examples would be `KC_ESC`, `KC_C`, `KC_4`, and even modifiers such as `KC_LSFT` and `KC_LGUI`.
 
-#### `unregister_code(<kc>);`
+### `unregister_code(<kc>);`
 
 Parallel to `register_code` function, this sends the `<kc>` keyup event to the computer. If you don't use this, the key will be held down until it's sent.
 
-#### `clear_keyboard();`
+### `clear_keyboard();`
 
 This will clear all mods and keys currently pressed.
 
-#### `clear_mods();`
+### `clear_mods();`
 
 This will clear all mods currently pressed.
 
-#### `clear_keyboard_but_mods();`
+### `clear_keyboard_but_mods();`
 
 This will clear all keys besides the mods currently pressed.
 
-# Advanced Example: Single-key copy/paste
+## Advanced Example: Single-key copy/paste
 
 This example defines a macro which sends `Ctrl-C` when pressed down, and `Ctrl-V` when released.