down file snippet

d.c

/*************************************************************************
    > File Name: d.c
    > Author: jige003
    > Created Time: Tue 14 May 2019 07:21:06 PM CST
 ************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include <string.h>
#include <stdbool.h>
#include <libgen.h>

#include <sys/stat.h>
#include <curl/curl.h>
#include <event2/http.h>
#include <event2/util.h>

size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb, void *stream) {
    int r;
    long len = 0;
    r = sscanf(ptr, "Content-Length: %ld\n", &len);
    if (r)
        *((long *) stream) = len;
    return (size * nmemb);
}

size_t wirtefunc(void *ptr, size_t size, size_t nmemb, void *stream){
    return fwrite(ptr, size, nmemb, stream);
}

int download(CURL *curlhandle, const char * remotepath, const char * localpath, long tries, bool ver){

    FILE *f;
    curl_off_t local_file_len = -1 ;
    long filesize =0 ;

    CURLcode r = CURLE_GOT_NOTHING;
    int c;
    struct stat file_info;
    int use_resume = 0;

    if(stat(localpath, &file_info) == 0) {
        local_file_len =  file_info.st_size;
        use_resume  = 1;
    }
    f = fopen(localpath, "ab+");
    if (f == NULL) {
        perror(NULL);
        return 0;
    }


    //curl_easy_setopt(curlhandle, CURLOPT_PROXY, "proxyip");
    curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath);

    //curl_easy_setopt(curlhandle, CURLOPT_CONNECTTIMEOUT, timeout);
    curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
    curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &filesize);
    curl_easy_setopt(curlhandle, CURLOPT_RESUME_FROM_LARGE, use_resume?local_file_len:0);
    curl_easy_setopt(curlhandle, CURLOPT_WRITEDATA, f);
    curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, wirtefunc);
    curl_easy_setopt(curlhandle, CURLOPT_NOPROGRESS, 1L);
    if (ver == true )
        curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);

    r = curl_easy_perform(curlhandle);

    fclose(f);

    if (r == CURLE_OK)
        return 1;
    else {
        fprintf(stderr, "%s\n", curl_easy_strerror(r));
        return 0;
    }
}


void xfree(void *ptr){
    if (ptr != ((void*)0)) free(ptr);
}

int main(int c, char **v) {
    struct options {
        char *url;
        char *filepath;
        bool verbose;
    } o;

    memset(&o, 0, sizeof(o));

    int opt;

#define ff fprintf
    if (c < 3){
        ff(stderr, "usage:\n");
        ff(stderr, "%s -u url [ -f filepath ]\n", v[0]);
        return (1);
    }

    while ((opt = getopt(c, v, "u:f:v")) != -1) {
        switch(opt){
            case 'u': o.url = optarg; break;
            case 'f': o.filepath = strdup(optarg); break;
            case 'v': o.verbose = true; break;
            default : ff(stderr, "Unknown option %c\n", opt); break;
        }

    }

    struct evhttp_uri *uri;
    uri = evhttp_uri_parse(o.url);
    const char *path = evhttp_uri_get_path(uri);
    ff(stdout, "path:%s\n", path);
    char *filename = basename((char*)path);
    ff(stdout, "filename:%s\n", filename);
    if (o.filepath == NULL){
        o.filepath = strdup(filename);
    }

	CURL *curlhandle = NULL;

	curl_global_init(CURL_GLOBAL_ALL);
	curlhandle = curl_easy_init();

    download(curlhandle, o.url, o.filepath, 3, o.verbose);

    curl_easy_cleanup(curlhandle);
	curl_global_cleanup();

    xfree(o.filepath);
	return (0);
}