c语言实现sftp上传文件
时间: 2023-11-24 10:50:10 浏览: 175
SFTP是Secure File Transfer Protocol的缩写,是一种安全的文件传输协议。下面是C语言实现SFTP上传文件的步骤:
1. 引入必要的头文件和库文件,包括libssh2库和WinSock2.h头文件。
2. 初始化socket库,使用initSocket()函数。
3. 建立SFTP连接,使用libssh2_session_init()函数初始化会话,使用libssh2_session_handshake()函数握手建立连接。
4. 认证用户身份,使用libssh2_userauth_password()函数或libssh2_userauth_publickey_fromfile()函数进行密码或公钥认证。
5. 打开本地文件,使用fopen()函数打开本地文件。
6. 创建远程文件,使用libssh2_sftp_open()函数创建远程文件。
7. 读取本地文件内容,使用fread()函数读取本地文件内容。
8. 将本地文件内容写入远程文件,使用libssh2_sftp_write()函数将本地文件内容写入远程文件。
9. 关闭本地文件和远程文件,使用fclose()函数和libssh2_sftp_close()函数。
10. 关闭SFTP连接,使用libssh2_session_disconnect()函数和libssh2_session_free()函数。
下面是一个简单的C语言实现SFTP上传文件的代码示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libssh2.h>
#include <WinSock2.h>
#define REMOTE_FILE_PATH "/path/to/remote/file"
#define LOCAL_FILE_PATH "C:\\path\\to\\local\\file"
int main()
{
int rc;
int sock;
struct sockaddr_in sin;
const char *username = "username";
const char *password = "password";
const char *remote_file_path = REMOTE_FILE_PATH;
const char *local_file_path = LOCAL_FILE_PATH;
FILE *local_file;
LIBSSH2_SESSION *session;
LIBSSH2_SFTP *sftp_session;
LIBSSH2_SFTP_HANDLE *sftp_handle;
char buffer[1024];
size_t nread;
size_t total = 0;
// 初始化socket库
rc = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (rc != 0) {
fprintf(stderr, "WSAStartup failed: %d\n", rc);
return 1;
}
// 建立socket连接
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == INVALID_SOCKET) {
fprintf(stderr, "socket failed: %ld\n", WSAGetLastError());
WSACleanup();
return 1;
}
// 设置socket地址
sin.sin_family = AF_INET;
sin.sin_port = htons(22);
sin.sin_addr.s_addr = inet_addr("192.168.1.1");
// 连接远程主机
rc = connect(sock, (struct sockaddr*)(&sin), sizeof(struct sockaddr_in));
if (rc != 0) {
fprintf(stderr, "connect failed: %d\n", WSAGetLastError());
closesocket(sock);
WSACleanup();
return 1;
}
// 初始化会话
session = libssh2_session_init();
if (session == NULL) {
fprintf(stderr, "libssh2_session_init failed\n");
closesocket(sock);
WSACleanup();
return 1;
}
// 握手建立连接
rc = libssh2_session_handshake(session, sock);
if (rc != 0) {
fprintf(stderr, "libssh2_session_handshake failed: %d\n", rc);
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
return 1;
}
// 用户名密码认证
rc = libssh2_userauth_password(session, username, password);
if (rc != 0) {
fprintf(stderr, "libssh2_userauth_password failed: %d\n", rc);
libssh2_session_disconnect(session, "Failed to authenticate");
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
return 1;
}
// 创建SFTP会话
sftp_session = libssh2_sftp_init(session);
if (sftp_session == NULL) {
fprintf(stderr, "libssh2_sftp_init failed\n");
libssh2_session_disconnect(session, "Failed to create SFTP session");
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
return 1;
}
// 打开本地文件
local_file = fopen(local_file_path, "rb");
if (local_file == NULL) {
fprintf(stderr, "fopen failed: %s\n", strerror(errno));
libssh2_sftp_shutdown(sftp_session);
libssh2_session_disconnect(session, "Failed to open local file");
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
return 1;
}
// 创建远程文件
sftp_handle = libssh2_sftp_open(sftp_session, remote_file_path, LIBSSH2_FXF_WRITE|LIBSSH2_FXF_CREAT|LIBSSH2_FXF_TRUNC, LIBSSH2_SFTP_S_IRUSR|LIBSSH2_SFTP_S_IWUSR|LIBSSH2_SFTP_S_IRGRP|LIBSSH2_SFTP_S_IROTH);
if (sftp_handle == NULL) {
fprintf(stderr, "libssh2_sftp_open failed\n");
fclose(local_file);
libssh2_sftp_shutdown(sftp_session);
libssh2_session_disconnect(session, "Failed to create remote file");
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
return 1;
}
// 读取本地文件内容并写入远程文件
do {
nread = fread(buffer, 1, sizeof(buffer), local_file);
if (nread <= 0) {
break;
}
rc = libssh2_sftp_write(sftp_handle, buffer, nread);
if (rc != nread) {
fprintf(stderr, "libssh2_sftp_write failed: %d\n", rc);
fclose(local_file);
libssh2_sftp_close(sftp_handle);
libssh2_sftp_shutdown(sftp_session);
libssh2_session_disconnect(session, "Failed to write to remote file");
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
return 1;
}
total += nread;
} while (1);
// 关闭本地文件和远程文件
fclose(local_file);
libssh2_sftp_close(sftp_handle);
libssh2_sftp_shutdown(sftp_session);
// 关闭SFTP连接
libssh2_session_disconnect(session, "Normal shutdown");
libssh2_session_free(session);
closesocket(sock);
WSACleanup();
printf("Upload succeeded, %d bytes uploaded.\n", total);
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