Helpers shared by two tasks

The code

Embedded C for Cortex-M. It compiles. There are 3 real bugs in it: the kind that pass a bench test and fail in the field.

const char *ip_to_str(uint32_t ip)
{
    static char buf[16];
    sprintf(buf, "%u.%u.%u.%u", (unsigned)(ip >> 24), (unsigned)(ip >> 16) & 0xFFu,
            (unsigned)(ip >> 8) & 0xFFu, (unsigned)ip & 0xFFu);
    return buf;
}

int parse_args(char *line, char *argv[], int max)
{
    int n = 0;
    char *tok = strtok(line, " ");
    while (tok && n < max) {
        argv[n++] = tok;
        tok = strtok(NULL, " ");
    }
    return n;
}

void log_peer(uint32_t local, uint32_t remote)
{
    log_line("link %s -> %s", ip_to_str(local), ip_to_str(remote));
}

What an interviewer expects

• Point to each line you'd stop in a code review.
• Say what actually breaks: the failure mode, not just the rule it violates.
• Fix it, then defend the fix when asked the follow-up.

The bugs, reference fixes and the follow-up question are in the practice app, after you've tried it.

Companies that test this

Matched on the skills each company's embedded roles emphasise.

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