c语言实现ssh远程连接

要在C语言中实现SSH远程连接，你可以使用开源的libssh库。下面是一个简单的示例代码，演示如何连接到远程SSH服务器并执行命令：

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

int main() {
    ssh_session my_ssh_session;
    int rc;

    // 创建一个新的SSH会话对象
    my_ssh_session = ssh_new();

    if (my_ssh_session == NULL) {
        fprintf(stderr, "Failed to create SSH session\n");
        exit(1);
    }

    // 设置SSH会话的选项
    ssh_options_set(my_ssh_session, SSH_OPTIONS_HOST, "remote_host");
    ssh_options_set(my_ssh_session, SSH_OPTIONS_USER, "username");

    // 连接到远程SSH服务器
    rc = ssh_connect(my_ssh_session);
    if (rc != SSH_OK) {
        fprintf(stderr, "Error connecting to remote host: %s\n", ssh_get_error(my_ssh_session));
        ssh_free(my_ssh_session);
        exit(1);
    }

    // 进行用户身份验证
    rc = ssh_userauth_password(my_ssh_session, NULL, "password");
    if (rc != SSH_AUTH_SUCCESS) {
        fprintf(stderr, "Error authenticating with password: %s\n", ssh_get_error(my_ssh_session));
        ssh_disconnect(my_ssh_session);
        ssh_free(my_ssh_session);
        exit(1);
    }

    // 在远程服务器上执行命令
    ssh_channel channel;
    char buffer[256];
    int nbytes;

    channel = ssh_channel_new(my_ssh_session);
    if (channel == NULL) {
        fprintf(stderr, "Failed to create SSH channel\n");
        ssh_disconnect(my_ssh_session);
        ssh_free(my_ssh_session);
        exit(1);
    }

    rc = ssh_channel_open_session(channel);
    if (rc != SSH_OK) {
        fprintf(stderr, "Error opening SSH channel: %s\n", ssh_get_error(my_ssh_session));
        ssh_channel_free(channel);
        ssh_disconnect(my_ssh_session);
        ssh_free(my_ssh_session);
        exit(1);
    }

    rc = ssh_channel_request_exec(channel, "command_to_execute");
    if (rc != SSH_OK) {
        fprintf(stderr, "Error executing command: %s\n", ssh_get_error(my_ssh_session));
        ssh_channel_close(channel);
        ssh_channel_free(channel);
        ssh_disconnect(my_ssh_session);
        ssh_free(my_ssh_session);
        exit(1);
    }

    nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
    while (nbytes > 0) {
        if (fwrite(buffer, 1, nbytes, stdout) != nbytes) {
            fprintf(stderr, "Error writing to stdout\n");
            ssh_channel_close(channel);
            ssh_channel_free(channel);
            ssh_disconnect(my_ssh_session);
            ssh_free(my_ssh_session);
            exit(1);
        }
        nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
    }

    if (nbytes < 0) {
        fprintf(stderr, "Error reading from SSH channel: %s\n", ssh_get_error(my_ssh_session));
        ssh_channel_close(channel);
        ssh_channel_free(channel);
        ssh_disconnect(my_ssh_session);
        ssh_free(my_ssh_session);
        exit(1);
    }

    // 关闭SSH通道和会话
    ssh_channel_send_eof(channel);
    ssh_channel_close(channel);
    ssh_channel_free(channel);
    ssh_disconnect(my_ssh_session);
    ssh_free(my_ssh_session);

    return 0;
}

请确保将 "remote_host" 替换为远程SSH服务器的主机名或IP地址，"username" 替换为您的SSH用户名，"password" 替换为您的SSH密码，"command_to_execute" 替换为要在远程服务器上执行的命令。

这只是一个基本示例，libssh库还提供了许多其他功能和选项，你可以根据需要进行进一步的定制和扩展。