libssh2:如何通过libssh2_channel_write发送数据

Question

编辑:这是完整的代码。修改了代码以使用路由器，但用例是相同的。一旦我使用libssh2_channel_write()发出密码，随后的libssh2_channel_read()就会失败，并返回LIBSSH2_ERROR_SOCKET_RECV。不知道为什么。我无法向远程设备发送后续命令并获取其输出。

逻辑是在远程设备( libssh2_channel_exec )上执行命令。此命令的执行将抛出一个密码，供客户端输入。现在通过libssh2_channel_read()读取流，并确保正在询问密码，并通过libssh2_channel_write()将密码写入通道。通过执行后续读取，确保密码在远程设备上被接受。这就是LIB使用ERROR_SOCKET_RECV失败的地方，然后通过libssh2_channel_write()发送要执行的命令，并读取命令输出。我是不是漏掉了什么？

    for( ;; )
    {
        /* loop until we block */ 
        int rc;
        do
        {
            char buffer[0x4000];
            rc = libssh2_channel_read( channel, buffer, sizeof(buffer) );

            if( rc > 0 )
            {
                int i;
                char *enable = "check-password\n";
                int ret;
                bytecount += rc;
                fprintf(stderr, "We read [%d] bytes:\n", bytecount);
                fputc('[', stderr);
                for( i=0; i < rc; ++i )
                    fputc( buffer[i], stderr);
                fputc(']', stderr);


                if ( strstr(buffer, "Password:") != NULL ){
                    fprintf(stderr, "Sending the password now\n");
                    while((ret = libssh2_channel_write(channel, enable, strlen(enable))) == LIBSSH2_ERROR_EAGAIN) {
                        printf("ERROR_EAGAIN - sending password again\n");
                    }

                    fprintf(stderr, "Wrote [%d] bytes: \n", ret);
                    flag = 1;
                    continue;
                }
                if (!flag){ // start
                    char *cmd = "show clock\n";
                    int ret;
                    fprintf(stderr, "THIS Fetching show clock command now\n");
                    while((ret = libssh2_channel_write(channel, cmd, strlen(cmd))) == LIBSSH2_ERROR_EAGAIN) {
                        printf("ERROR_EAGAIN - sending show clock again\n");
                    }
                    flag = 1;
                } // end
            }
            else {
                if(rc != LIBSSH2_ERROR_EAGAIN)
                    fprintf(stderr, "libssh2_channel_read returned [%d]:\n ", rc);
            }
        }
        while( rc > 0 );

        /* this is due to blocking that would occur otherwise so we loop on
           this condition */ 
        if( rc == LIBSSH2_ERROR_EAGAIN )
        {
            int check;
            check = waitsocket(sock, session);
        }
        else
            break;
    }

Answer 1

为了遵循规则，我创建了一个包含我的问题的新帖子。此答案应删除。

谢谢。

Zeev