libcurl之ftp上传 & 下载

    由于项目的需要，利用libcurl编写程序与ftp服务器通信，进行文件上传或下载，愈发地感到curl功能的强悍。其实在命令行下直接使用curl命令就可以完成这些功能，但是需要获取上传下载行为的状态以便更好地控制。直接上代码：

//ftp-manager.h

#ifndef _FTP_MANAGER_H_
#define _FTP_MANAGER_H_

/*FTP OPERATION CODE*/
typedef enum FTP_STATE
{
	FTP_UPLOAD_SUCCESS,
	FTP_UPLOAD_FAILED,
	FTP_DOWNLOAD_SUCCESS,
	FTP_DOWNLOAD_FAILED 
}FTP_STATE;

/*FTP OPERATIONS OPTIONS*/
typedef struct FTP_OPT
{
	char *url;		/*url of ftp*/
	char *user_key;		/*username:password*/
	char *file;		/*filepath*/
}FTP_OPT;

#ifdef __cplusplus
	extern "C" {
#endif

/*upload file to ftp server*/
FTP_STATE ftp_upload(const FTP_OPT ftp_option);

/*download file from ftp server*/
FTP_STATE ftp_download(const FTP_OPT ftp_option);

#ifdef __cplusplus
	}
#endif

#endif

//ftp-manager.c

#include <stdio.h>
#include <stdlib.h>
#include <curl/curl.h>

#include "ftp-manager.h"

/*****************util api******************/
int get_file_size(FILE *file)
{
	int size = 0;
	fseek(file, 0L, SEEK_END);
	size = ftell(file);
	fseek(file, 0L, SEEK_SET);
	return size;
}

/******************curl api****************/
CURL *curl_init()
{
	curl_global_init(CURL_GLOBAL_DEFAULT); 
	CURL *curl = curl_easy_init();
	if(NULL == curl)
	{
		fprintf(stderr, "Init curl failed.\n");
		exit(1);
	}
	return curl;
}

void curl_set_upload_opt(CURL *curl, const char *url, const char *user_key, FILE *file)
{
	curl_easy_setopt(curl, CURLOPT_URL, url);
	curl_easy_setopt(curl, CURLOPT_USERPWD, user_key);
	curl_easy_setopt(curl, CURLOPT_READDATA, file);	
	curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);
	curl_easy_setopt(curl, CURLOPT_INFILESIZE, get_file_size(file));
	curl_easy_setopt(curl, CURLOPT_FTP_CREATE_MISSING_DIRS, 1);
//	curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
}

void curl_set_download_opt(CURL *curl, const char *url, const char *user_key, FILE *file)
{
	curl_easy_setopt(curl, CURLOPT_URL, url);
	curl_easy_setopt(curl, CURLOPT_USERPWD, user_key);
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, file);
//	curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
}

void curl_exit(CURL *curl)
{
	curl_easy_cleanup(curl);
	curl_global_cleanup(); 
}

CURLcode curl_perform(CURL *curl)
{
	CURLcode ret = curl_easy_perform(curl);
	if(ret != 0)
	{
		fprintf(stderr, "Perform curl failed.\n");
		curl_exit(curl);
		exit(1);
	}
	return ret;
}

/****************ftp upload & download api******************/
FTP_STATE ftp_upload(const FTP_OPT ftp_option)
{
	FTP_STATE state;
	CURL *curl;;
	FILE *fp = fopen(ftp_option.file, "r");
	if(NULL == fp)
	{
		fprintf(stderr, "Open file failed at %s:%d\n", __FILE__, __LINE__);
		return FTP_UPLOAD_FAILED;
	}

	curl = curl_init();
	curl_set_upload_opt(curl, ftp_option.url, ftp_option.user_key, fp);
	if(CURLE_OK == curl_perform(curl))
		state = FTP_UPLOAD_SUCCESS;
	else
		state = FTP_UPLOAD_FAILED;

	curl_exit(curl);
	fclose(fp);
	return state;
}

FTP_STATE ftp_download(const FTP_OPT ftp_option)
{
	FTP_STATE state;
	CURL *curl;
	FILE *fp = fopen(ftp_option.file, "w");
	if(NULL == fp)
	{
		fprintf(stderr, "Open file failed at %s:%d\n", __FILE__, __LINE__);
		return FTP_UPLOAD_FAILED;
	}

	curl = curl_init();
	curl_set_download_opt(curl, ftp_option.url, ftp_option.user_key, fp);
	if(CURLE_OK == curl_perform(curl))
		state = FTP_DOWNLOAD_SUCCESS;
	else
		state = FTP_DOWNLOAD_FAILED;

	curl_exit(curl);
	fclose(fp);
	return state;
}

//test.c

#include <stdio.h>

#include "ftp-manager.h"

int main()
{
	FTP_OPT ftp_opt;
	ftp_opt.url = "ftp://127.0.0.1//var/ftp/upload.txt";
	ftp_opt.user_key = "xxx:xxx";
	ftp_opt.file = "/home/xxx/project/ftpManager/upload.txt";

	if(FTP_UPLOAD_SUCCESS == ftp_upload(ftp_opt))
		printf("Upload success.\n");
	else
		printf("Upload failed.\n");

	ftp_opt.url = "ftp://127.0.0.1//var/ftp/download.txt";
	ftp_opt.file = "/home/xxx/project/ftpManager/download.txt";

	if(FTP_DOWNLOAD_SUCCESS == ftp_download(ftp_opt))
		printf("Download success.\n");
	else
		printf("Download failed.\n");

	return 0;
}