Configure stdin on Zephyr Shell subsystem for a working scanf()

shell_stdin_hook.c

#include <zephyr/shell/shell_uart.h>

static unsigned char shell_stdin_hook(void)
{
    const struct shell * sh = shell_backend_uart_get_ptr();

    char ch;
    size_t count = 0;

    while (count == 0) {
        (void)sh->iface->api->read(sh->iface, &ch, sizeof(ch), &count);
        k_usleep(100); // yield to other threads
    }

    if (ch == '\r') {
        putchar('\r');
        putchar('\n');
    } else {
        putchar(ch);
    }

    return ch;
}


// Somewhere in your init code:
__stdin_hook_install(shell_stdin_hook); // to get input for scanf()