[系统运维]Intel 实习mentor布置问题1

可视化界面下的Terminal和ssh下启动的Terminal二者之间的区别。

二者都是伪终端，与物理终端相互区别。物理终端是本地直接关联了物理设备，伪终端则是通过软件方法来实现。二者都是完成于主机间的IO。

可以通过tty命令来查看当前终端机连接标准输入设备的文件名称。

具体区别在于

伪终端的两种情况：

第一是在Xwindows（桌面GUI环境之下）模式下的启动的终端称之为伪终端；

第二是在远程如果用telnet远程登录的话，也是创建的一个伪终端

Linux设计出一对虚拟终端设备，即/dev/ptmx和/dev/pts/X。这就跟TUN/TAP网卡的网卡与字符设备之前的对应关系一致。

简单来讲，当有ssh客户端连接后，sshd会fork一个进程，然后在子进程中打开一个叫做/dev/pts/1(或者2,3,4,5…)的设备，然后和sshd进程的/dev/ptmx配对，这样在ptmx与pts之间就构成了一条管道，数据可以顺利被导入到sshd，然后通过TCP/IP封装发往ssh client所在的机器。
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Telnet provides the ability to communicate with a service, nothing more nothing less. If that service happens to be a shell on a server, great, but it’s not always. I often use telnet to send a malformed HTTP request manually, or to manually run commands against an SMTP server.

SSH is way more than just a way of logging on to a server remotely. It can be used as a proxy to access remote services from your local computer, and it can be used as a protocol to run other protocols over (like scp)

A Shell is the name given to a command-line interpreter that runs on a computer to figure out what you’re wanting to do and tries to do it. This could be sh, bash, csh, tcsch or even command.com

Command Line is the DOS shell, usually associated with Microsoft operating systems.

A terminal is ambiguous. It could be the OS X name for the shortcut to their shell. It could also be a physical thing that was used to interface with the shell of a multi-user Unix server (a popular one is the VT-100)

What is the Linux version commonly called, is it just called SSH ?

SSH is just a protocol that can access the shell of the server. It is extremely common, but there’s also the older and insecure rsh or you can even log in to your Linux server with telnet if you’re so inclined.

https://blog.csdn.net/qq_27825451/article/details/101307195/
https://serverfault.com/questions/429677/confusion-over-terminology-ssh-shell-terminal-command-prompt-and-telnet