linuxc基于libcurl库的ftp上传和下载代码

1、linux c 基于 libcurl 库的 ftp 上传和下载代码昨天考虑好了 IM 传送图片的方式，用的是 FTP 做缓存来传递图片，以减少聊天服务器的压力，用的是 libcurl 库，自己载了一个 Server-U 服务器， 下面是测试程序， 上传和下载都跑通了，剩下的就是在程序中写逻辑来实现具体的功能了。传代码：cpp view plain copy print?/ftp 上传实例/ 服务器地址：85 账号：spider 密码：spider/ 在服务器路径 a上建立一个 a.txt ，本地文件是 test.txt/ 命令行参数85 spider

2、 spider a a.txt D:/test.txt /#include<stdlib.h>/#include <stdio.h>/#include<curl/curl.h>/#include <string.h>/ /intdebugFun(CURL* curl, curl_infotype type, char* str, size_t len,void* stream)/ / 只打印 CURLINFO_TEXT类型的信息/ if(type = CURLINFO_TEXT)/f

3、write(str, 1, len, (FILE*)stream);/ /return 0;/ / /int main(int argc, char* argv)/ CURL* curl;/ CURLcode res; / FILEchar errorBufCURL_ERROR_SIZE;*sendFile, *debugFile;/ char ftpurl256 + 1;/char usrpasswd64 + 1;/ / curl_slist *slist=NULL;/ / if(argc != 7)/ /printf("Usage:nt./ftp ip username pass

4、word ftpPathdestFileName srcFile"); /return -1;/ /将相关的调试信息打印到 dubugFile.txt匚=f/if(NULL = (debugFile = fopen("debugFile.txt", "a+")/return -1;/ /打开 ftp 上传的源文件/if(NULL = (sendFile = fopen(argv6, "r")/fclose(debugFile); /return -1; /获取需要发送文件的大小/ fseek(sendFile, 0,SEEK

5、_END);/int sendSize = ftell(sendFile);/if(sendSize < 0)/fclose(debugFile);/fclose(sendFile);/return -1; /fseek(sendFile, 0L,SEEK_SET); /if(res =curl_global_init(CURL_GLOBAL_ALL) != 0)/ /fclose(debugFile); /fclose(sendFile); /return -1;/if(curl = curl_easy_init() = NULL)/fclose(debugFile); /fc

6、lose(sendFile);/curl_global_cleanup(); /return -1;/ / if(argv4strlen(argv4) - 1 != '/')/ else /sprintf(ftpurl, "ftp:/%s/%s/%s", argv1, argv4, argv5);sprintf(ftpurl, "ftp:/%s/%s%s",argv1, argv4, argv5);/ curl_easy_setopt(curl,CURLOPT_URL, ftpurl);/设置 ftp 上传 url, 组成如的 URL /

7、45/root/subdir/curl/testftp.txt/ /sprintf(usrpasswd, "%s:%s", argv2, argv3);/curl_easy_setopt(curl, CURLOPT_USERPWD, usrpasswd);/ / curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);/ curl_easy_setopt(curl, CURLOPT_DEBUGDATA,debugFile); / / curl_easy_setopt(curl,CURLOPT_READDATA,

8、 sendFile);/curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);/curl_easy_setopt(curl, CURLOPT_INFILESIZE, sendSize);/ curl_easy_setopt(curl,CURLOPT_FTP_CREATE_MISSING_DIRS, 1);/curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION,debugFun); / res = curl_easy_perform(curl);/if(0 != res) / /fclose(sendFile);/fclose(d

9、ebugFile);/curl_easy_cleanup(curl);/curl_global_cleanup(); /return -1;/ / / curl_easy_cleanup(curl);/fclose(sendFile); / fclose(debugFile);/curl_global_cleanup(); / getchar(); /return 0;/载代码如下： cpp view plain copy print?/ftp载实例#include <stdio.h> #include <curl/curl.h>#inc

10、lude <curl/types.h> #include <curl/easy.h>struct FtpFile/定义一个结构为了传递给 my_fwrite 函数 .可用 curl_easy_setopt 的 CURLOPT_WRITEDATA 选项传递char *filename;FILE *stream; ;int my_fwrite(void *buffer, size_t size, size_t nmemb, void*stream) struct FtpFile *out=(struct FtpFile*)stream; /

11、stream 指针其实就是指向 struct FtpFile ftpfile 的if(out && !out->stream)out->stream=fopen(out->filename, "wb"); / 没有这个流的话就创建一个名字是out->filename.if(!out->stream)return -1;return fwrite(buffer, size,nmemb, out->stream);int main(int argc, char*a

12、rgv) CURL *curl;ftpfile="D:/Success.txt",NULL; / 初始化一个 FtpFile 结构curl_global_init(CURL_GLOBAL_DEFAULT);curl = curl_easy_init();if(curl)curl_easy_setopt(curl,CURLOPT_URL,"85/a/a.txt");curl_easy_setopt(curl, CURLOPT_USERPWD,"spider:spider");curl_easy_setop

13、t(curl, CURLOPT_WRITEFUNCTION,my_fwrite);curl_easy_setopt(curl,CURLOPT_WRITEDATA, &ftpfile); / 给相关函数的第四 个参数传递一个结构体的指针curl_easy_setopt(curl, CURLOPT_VERBOSE,TRUE);/CURLOPT_VERBOSE 这个选项很常用用来在屏幕显示对服务器相关操作返回的信息res = curl_easy_perform(curl);curl_easy_cleanup(curl);if(CURLE_OK != res)fprintf(stder

14、r, "curl told us %dn", res);if(ftpfile.stream)fclose(ftpfile.stream);curl_global_cleanup();return 0; 最后记录一个比较好用的：cpp view plain copy#include <stdio.h>print?#include <stdlib.h>CURLE_GOT_NOTHING;int c;#include <curl/curl.h> #include <sys/stat.

15、h> /* parse headers for Content-Length */ size_tgetcontentlengthfunc(void *ptr, size_t size, size_t nmemb, void*stream) int r;long len = 0;/*_snscanf() is Win32 specific */r = _snscanf(ptr, size *nmemb, "Content-Length: %ldn", &len);sscanf(const char*)ptr, "Content-Leng

16、th: %ldn", &len);if (r) /* Microsoft: we don't read the specs */*(long*) stream) = len;return size * nmemb; /* discarddownloaded data */ size_t discardfunc(void *ptr, size_t size,size_t nmemb, void *stream) return size *nmemb; /write data to upload size_t writefunc(void *ptr,size_t

17、size, size_t nmemb, void *stream) returnfwrite(ptr, size, nmemb, (FILE*)stream); /* read data toupload */ size_t readfunc(void *ptr, size_t size, size_t nmemb,void *stream) FILE *f = (FILE*)stream;size_tn;if (ferror(f)returnCURL_READFUNC_ABORT;n = fread(ptr, size,/* are we resuming? */if (c) /* yes

18、*/nmemb, f) * size;return n; int upload(CURL*curlhandle, const char * remotepath, const char * localpath,long timeout, long tries) FILE *f;longfopen(localpath, "rb");if (f = NULL)perror(NULL);return 0;curl_easy_setopt(curlhandle, CURLOPT_UPLOAD, 1L);curl_easy_setopt(curlhandle, CURLOPT_URL

19、, remotepath);curl_easy_setopt(curlhandle, CURLOPT_USERPWD,"spider:spider");if (timeout)curl_easy_setopt(curlhandle,CURLOPT_FTP_RESPONSE_TIMEOUT, timeout);curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION,getcontentlengthfunc);curl_easy_setopt(curlhandle,CURLOPT_HEADERDATA, &uplo

20、aded_len);curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION,discardfunc);curl_easy_setopt(curlhandle,CURLOPT_READFUNCTION, readfunc);curl_easy_setopt(curlhandle, CURLOPT_READDATA, f);curl_easy_setopt(curlhandle, CURLOPT_FTPPORT, "-"); /*disable passive mode */curl_easy_setopt(curlhandle,C

21、URLOPT_FTP_CREATE_MISSING_DIRS, 1L);curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);for (c = 0; (r != CURLE_OK) && (c < tries); c+)return 0; / 下载 int download(CURL/*will issue a SIZEto retrieve the result is* to parse the returnedContent-Length header. Thus,getcontentlengthf

22、unc(). We need discardfunc() above* because HEADER will dump the headers to stdout* without it.*/curl_easy_setopt(curlhandle, CURLOPT_NOBODY , 1L);curl_easy_setopt(curlhandle, CURLOPT_HEADER, 1L);r = curl_easy_perform(curlhandle);if (r !=CURLE_OK)continue;curl_easy_setopt(curlhandle, CURLOPT_NOBODY

23、, 0L);curl_easy_setopt(curlhandle, CURLOPT_HEADER, 0L);fseek(f, uploaded_len, SEEK_SET);curl_easy_setopt(curlhandle, CURLOPT_APPEND,1L);else /* no */curl_easy_setopt(curlhandle, CURLOPT_APPEND,0L);curl_easy_perform(curlhandle);fclose(f);if (r = CURLE_OK)return 1;else/* determine the length of the fi

24、le already written */ * With NOBODY and NOHEADER, libcurl* command, but the only wayfprintf(stderr, "%sn", curl_easy_strerror(r);*curlhandle, const char * remotepath, const char * localpath,long timeout, long tries) FILE *f;curl_off_tlocal_file_len = -1 ;long filesize =0 ;CURLcode r= CURLE

25、_GOT_NOTHING;struct stat file_info;int use_resume = 0;/获取本地文件大小信息if(stat(localpath, &file_info) = 0)local_file_len = file_info.st_size;use_resume = 1;/追加方式打开文件，实现断点续传f = fopen(localpath, "ab+");if (f = NULL)perror(NULL);return 0;curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath)

26、;curl_easy_setopt(curlhandle, CURLOPT_USERPWD, curl_easy_setopt(curlhandle,"spider:spider");/连接超时设置curl_easy_setopt(curlhandle,CURLOPT_CONNECTTIMEOUT, timeout);/设置头处理函数curl_easy_setopt(curlhandle,CURLOPT_HEADERFUNCTION, getcontentlengthfunc);curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA,