Function cbm_replace_binary

src/cli/cli.c:400–447

Replace a binary file. Unlinks the old file first (handles read-only and * running binaries on Unix where unlink succeeds on open files). On all * platforms, the caller should tell the user to restart after update. */

 * running binaries on Unix where unlink succeeds on open files). On all
 * platforms, the caller should tell the user to restart after update. */
int cbm_replace_binary(const char *path, const unsigned char *data, int len, int mode) {
    if (!path || !data || len <= 0) {
        return CLI_ERR;
    }

    /* Remove existing file if it exists. On Unix, unlink works even if the
     * binary is running (inode stays alive until the process exits). On Windows,
     * unlink fails on running .exe — rename it aside as fallback. */
    struct stat st_check;
    if (stat(path, &st_check) == 0) {
        /* File exists — remove or rename it */
        if (cbm_unlink(path) != 0) {
#ifdef _WIN32
            /* Windows: can't unlink running .exe — rename aside */
            char old_path[CLI_BUF_1K];
            snprintf(old_path, sizeof(old_path), "%s.old", path);
            (void)cbm_unlink(old_path);
            if (rename(path, old_path) != 0) {
                return CLI_ERR;
            }
#else
            return CLI_ERR;
#endif
        }
    }

#ifndef _WIN32
    int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, (mode_t)mode);
    if (fd < 0) {
        return CLI_ERR;
    }
    FILE *f = fdopen(fd, "wb");
    if (!f) {
        close(fd);
        return CLI_ERR;
    }
#else
    (void)mode;
    FILE *f = fopen(path, "wb");
    if (!f) {
        return CLI_ERR;
    }
#endif

    size_t written = fwrite(data, CLI_ELEM_SIZE, (size_t)len, f);
    (void)fclose(f);
    return written == (size_t)len ? 0 : CLI_ERR;
}

/* ── Skill file content (embedded) ────────────────────────────── */