CTL_STATUS_t ctl_cli_gets(CTL_CLI_CONTEXT_t *self, char *buf, size_t len, size_t cursor);
ctl_cli_gets must be implemented by the user to read a line of text to process by the CLI. If ctl_cli_gets returns an error code, the read-eval-print loop is terminated.
ctl_cli_gets must be implemented to be thread-safe.