shell: Add built-in shell commands

Added optional shell commands:
- clear - for clearing terminal
- history - commands history
- resize - terminal resize
- shell - controling echo and colors

Signed-off-by: Krzysztof Chruscinski <[email protected]>
Signed-off-by: Jakub Rzeszutko <[email protected]>

Author: nordic-krch

subsys/shell/CMakeLists.txt

@@ -23,3 +23,8 @@ zephyr_sources_ifdef(
   CONFIG_SHELL_HISTORY
   shell_history.c
 )
+
+zephyr_sources_ifdef(
+  CONFIG_SHELL_CMDS
+  shell_cmds.c
+)

subsys/shell/Kconfig

@@ -135,4 +135,20 @@ config SHELL_HISTORY_BUFFER
 
 endif #SHELL_HISTORY
 
+config SHELL_CMDS
+	bool "Enable built-in commands"
+	default y
+	help
+	  Enable built-in commands like 'clear', 'history', etc.
+
+config SHELL_CMDS_RESIZE
+	bool "Enable resize command"
+	depends on SHELL_CMDS
+	default y
+	help
+	  By default shell assumes width of a terminal screen set to 80
+	  characters. Each time terminal screen width is changed resize command
+	  must be called to ensure correct text display on the terminal screen.
+	  Resize command can be turned off to safe code memory (~0,5k).
+
 endif #SHELL