Note 3.¶

SSH¶

相关文件：

local
- ~/.ssh/config
- ~/.ssh/filename
- ~/.ssh/filename.pub
remote
- ~/.ssh/authorized_keys

`~/.ssh/config`¶

$ cd ~
$ mkdir .ssh
$ cd .ssh
$ touch config
$ cat config

```filename="PATH: ~/.ssh/config"

¶

ssh config file¶

¶

Host * ForwardAgent yes ForwardX11 yes ServerAliveInterval 30

¶

Host cs102 HostName 106.14.165.94 User boaw Port 22 IdentityFile ~/.ssh/cs102

Host github.com HostName ssh.github.com User git Port 443

### 免密登录远程服务器

1.   Step 1 Generating an ssh public key and private key pair

2.   Step 2 Setup the remote host to accept your public/private key pair

3.   Step 3 Check that everything is working

4.   Step 4 SSH Agent

``` sh
# Generate an ed25519 key & Specify file in which to save the key:
$ ssh-keygen -t ed25519 -f ~/.ssh/filename
# Copy the given public key to the remote with specific port:
$ ssh-copy-id -i path/to/certificate -p port ${username}@${hostname}
$ chmod 600 ~/.ssh/authorized_keys
$ cat ~/.ssh/id_ed25519.pub | ssh -p 922 ${username}@${hostname} 'cat >> ~/.ssh/authorized_keys; chmod 600 ~/.ssh/authorized_keys'

id_ed25519.pub is the public key that will be added to the ~/.ssh/authorized_keys file on the server to allow you to login.

`sudo`¶

全新安装的 Ubuntu 系统默认 root 密码是随机的，每次开机都会有一个新的密码。

$ su root
Password:
su: Authentication failure
$ sudo passwd
$ sudo -v
[sudo] password for ubuntu:
$ sudo su -
#

脚本文件¶

自己写的脚本文件可以放在 ~/.local/bin 下面。

其他¶

$ vim hello.c
$ gcc hello.c -o hello
$ mkdir -p ~/.local/bin/
$ mv hello ~/.local/bin/
$ export PATH=$PATH:$HOME/.local/bin
$ echo $PATH | tr ':' '\n'
$ hello

Command list¶

which
whereis
tac