Function cbm_mkstemp

src/foundation/compat.c:252–302

#ifdef _WIN32
int cbm_mkstemp(char *tmpl) {
    /* Rewrite /tmp/ to %TEMP%\ like cbm_mkdtemp */
    /* Per-call storage: daemon project workers can create staging files
     * concurrently, so a process-global scratch buffer is a data race. */
    char buf[CBM_SZ_4K];
    int written;
    if (strncmp(tmpl, "/tmp/", 5) == 0) {
        const char *tmp = getenv("TEMP");
        if (!tmp)
            tmp = getenv("TMP");
        if (!tmp)
            tmp = ".";
        written = snprintf(buf, sizeof(buf), "%s\\%s", tmp, tmpl + 5);
    } else {
        written = snprintf(buf, sizeof(buf), "%s", tmpl);
    }
    if (written < 0 || (size_t)written >= sizeof(buf)) {
        errno = ENAMETOOLONG;
        return CBM_NOT_FOUND;
    }
    /* Wide-API expansion and open: worker staging files land inside
     * CBM_CACHE_DIR, which users may place at non-ASCII paths; the ANSI CRT
     * (_mktemp/_open) mangles those bytes in the local codepage. */
    wchar_t *wide_template = cbm_utf8_to_wide(buf);
    if (!wide_template || !_wmktemp(wide_template)) {
        free(wide_template);
        return CBM_NOT_FOUND;
    }
    char *expanded_for_open = cbm_wide_to_utf8(wide_template);
    wchar_t *wide_open = expanded_for_open ? cbm_path_to_wide(expanded_for_open) : NULL;
    free(expanded_for_open);
    if (!wide_open) {
        free(wide_template);
        return CBM_NOT_FOUND;
    }
    int fd = _wopen(wide_open, _O_CREAT | _O_EXCL | _O_RDWR | _O_BINARY, _S_IREAD | _S_IWRITE);
    free(wide_open);
    if (fd >= 0) {
        char *expanded = cbm_wide_to_utf8(wide_template);
        if (!expanded || strlen(expanded) >= sizeof(buf)) {
            free(expanded);
            free(wide_template);
            (void)_close(fd);
            return CBM_NOT_FOUND;
        }
        strcpy(tmpl, expanded);
        free(expanded);
    }
    free(wide_template);
    return fd;
}
#endif

/* ── clock_gettime (Windows lacks it) ─────────────────────────── */