struct-vis/visualization.h

static size_t indexHtmlSize = 0;
static char* indexHtml = NULL;

#define sb_concatf(fmt, ...) \
    if ((sbc - sbi) < 1024) { \
        sbc *= 1.5; \
        stringBuffer = realloc(stringBuffer, sbc); \
    } \
    if ((result = snprintf(stringBuffer + sbi, sbc - sbi, fmt, ##__VA_ARGS__)) > 0) sbi += result; \
    else die("fatal error concating to string");


static void outputHtml() {
    static int sbi = 0;
    static int sbc = 50 * 1024;
    static char* stringBuffer = NULL;

    if (stringBuffer == NULL) stringBuffer = malloc(sizeof(char) * sbc);
    if (indexHtml    == NULL) indexHtml = readWholeFile("base-index.html", &indexHtmlSize);

    int result = 0;
    sb_concatf("%s", indexHtml);

    for (int i = 0; i < numAllStructs; i++) {
        struct StructInfo *structInfo = allStructs + i;
        printStructInfo(structInfo);

        ssize_t byteCounter = 0;
        sb_concatf(
          "<div class='struct-info'>"
            "<label class='struct-info-header'>struct %s - alias: %s</label>"
            "<div class='struct-info-byte-row'>"
          , structInfo->name, structInfo->alias);
        for (int d = 0; d < structInfo->numDeclarations; d++) {
            struct Declaration *decl = structInfo->declarations + d;
            bool truncate32 = false;
            if (decl->size > 32) {
                truncate32 = true;
            }

            sb_concatf("%s", "<div class='struct-info-bytegroup'>");

            bool first = (d % 2) == 0;
            const char* positionClass = first ? "struct-info-declaration-top" : "struct-info-declaration-bottom";
            if (decl->size == -1) {
                sb_concatf(
                  "<div class='struct-info-byte struct-info-byte-unknown'>?"
                    "<div class='struct-info-declaration %s'>"
                      "%s <span class='struct-info-declaration-name'>%s</span>"
                    "</div>"
                  "</div>"
                  "<div class='struct-info-byte struct-info-byte-ellipsis'>...</div>"
                  , positionClass, decl->type, decl->name);
            } else {
                for (int b = 0; b < decl->size; b++) {
                    if (b == 0) {
                        sb_concatf(
                          "<div class='struct-info-byte struct-info-byte-first'>"
                            "<div class='struct-info-declaration %s'>"
                              "%s <span class='struct-info-declaration-name'>%s</span>"
                            "</div>"
                          "</div>"
                          , positionClass, decl->type, decl->name);
                    } else if (truncate32 && b == 32) {
                        sb_concatf("<div class='struct-info-byte struct-info-byte-counted-ellipsis'>...[%ld]</div>", decl->size - b);
                        break;

                    } else {
                        sb_concatf("%s", "<div class='struct-info-byte'></div>");
                    }
                }
            }
            sb_concatf("%s", "</div>");
        }
        sb_concatf("%s", "</div></div>");
    }

    // don't forget the closing body and html tags
    sb_concatf("%s", "</body></html>");

    // write the index.html file out to disk
    FILE* fp = fopen("index.html", "wb");
    if (fp == NULL) {
        die("failed to open the file index.html");
    }

    size_t writtenCount = fwrite(stringBuffer, 1, sbi, fp);
    fclose(fp);

    if (writtenCount != sbi) {
        die("wrote only partially");
    }
}