zephyr

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Keith Packard 0b90fd5adf samples, tests, boards: Switch main return type from void to int As both C and C++ standards require applications running under an OS to return 'int', adapt that for Zephyr to align with those standard. This also eliminates errors when building with clang when not using -ffreestanding, and reduces the need for compiler flags to silence warnings for both clang and gcc. Most of these changes were automated using coccinelle with the following script: @@ @@ - void + int main(...) { ... - return; + return 0; ... } Approximately 40 files had to be edited by hand as coccinelle was unable to fix them. Signed-off-by: Keith Packard <keithp@keithp.com>		2023-04-14 07:49:41 +09:00
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src	samples, tests, boards: Switch main return type from void to int	2023-04-14 07:49:41 +09:00
CMakeLists.txt
prj.conf
README.rst
sample.yaml

README.rst

.. _console_getchar_sample:

console_getchar() Sample Application
####################################

Overview
********

This example shows how to use :c:func:`console_getchar` function.
Similar to the well-known ANSI C getchar() function,
:c:func:`console_getchar` either returns the next available input
character or blocks waiting for one. Using this function, it should be
fairly easy to port existing ANSI C, POSIX, or Linux applications which
process console input character by character. The sample also allows to
see key/character codes as returned by the function.

If you are interested in line by line console input, see
:ref:`console_getline_sample`.


Requirements
************

UART console is required to run this sample.


Building and Running
********************

The easiest way to run this sample is using QEMU:

.. zephyr-app-commands::
   :zephyr-app: samples/subsys/console/getchar
   :host-os: unix
   :board: qemu_x86
   :goals: run
   :compact:

Now start pressing keys on a keyboard, and they will be printed both as
hex values and in character form. Be sure to press Enter, Up/Down, etc.
key to check what control characters are produced for them.
Exit QEMU by pressing :kbd:`CTRL+A` :kbd:`x`.