Linux企业级项目实践之网络爬虫（15）——区分文本文件和二进制文件

HTTP协议支持文本和二进制文件传输。最常见的html格式的页面即文本，图片、音乐等为二进制文件。我们要对这两类文件加以区分并分别处理。

static char * BIN_SUFFIXES = ".jpg.jpeg.gif.png.ico.bmp.swf";
static int is_bin_url(char *url)
{
    char *p = NULL;
    if ((p = strrchr(url, '.')) != NULL) {
        if (strstr(BIN_SUFFIXES, p) == NULL)
            return 0;
        else
            return 1;
    }
    return 0;
}

char * attach_domain(char *url, const char *domain)
{
    if (url == NULL)
        return NULL;

    if (strncmp(url, "http", 4) == 0) {
        return url;

    } else if (*url == '/') {
        int i;
        int ulen = strlen(url);
        int dlen = strlen(domain);
        char *tmp = (char *)malloc(ulen+dlen+1);
        for (i = 0; i < dlen; i++)
            tmp[i] = domain[i];
        for (i = 0; i < ulen; i++)
            tmp[i+dlen] = url[i];
        tmp[ulen+dlen] = '';
        free(url);
        return tmp;

    } else {
        //do nothing
        free(url);
        return NULL;
    }
}

char * url2fn(const Url * url)
{
    int i = 0;
    int l1 = strlen(url->domain);
    int l2 = strlen(url->path);
    char *fn = (char *)malloc(l1+l2+2);

    for (i = 0; i < l1; i++)
        fn[i] = url->domain[i];

    fn[l1++] = '_';

    for (i = 0; i < l2; i++)
        fn[l1+i] = (url->path[i] == '/' ? '_' : url->path[i]);

    fn[l1+l2] = '';

    return fn;
}