`echo "hello"`



打印变量信息，加$

```bash
momen@momen-PC:~$ echo SHELL
SHELL
momen@momen-PC:~$ echo $SHELL
/bin/bash
```

```bash
momen@momen-PC:~$ a=5
momen@momen-PC:~$ echo a
a
momen@momen-PC:~$ echo $a
5
```

echo xxx |more 

more命令可以分页显示



echo

```mermaid
graph TB;
1((1))-->2((2))
1((1))-->4((3))
44((44))-->3((3))

```

awk文本分析工具

nmap [ip] -v -p [端口范围]
```
root@momen-PC:~# nmap 192.168.1.1 -v -p 1-65535
Starting Nmap 7.80 ( https://nmap.org ) at 2023-01-27 13:16 CST
Initiating Ping Scan at 13:16
Scanning 192.168.1.1 [4 ports]
Completed Ping Scan at 13:16, 0.14s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 13:16
Completed Parallel DNS resolution of 1 host. at 13:16, 1.40s elapsed
Initiating SYN Stealth Scan at 13:16
Scanning 192.168.1.1 [65535 ports]
Discovered open port 8080/tcp on 192.168.1.1
Discovered open port 139/tcp on 192.168.1.1
Discovered open port 80/tcp on 192.168.1.1
Discovered open port 445/tcp on 192.168.1.1
Discovered open port 53/tcp on 192.168.1.1
Discovered open port 21/tcp on 192.168.1.1
Discovered open port 49653/tcp on 192.168.1.1
Discovered open port 37443/tcp on 192.168.1.1
Discovered open port 49652/tcp on 192.168.1.1
Discovered open port 17998/tcp on 192.168.1.1
Discovered open port 32768/tcp on 192.168.1.1
Discovered open port 37444/tcp on 192.168.1.1
Discovered open port 631/tcp on 192.168.1.1
Completed SYN Stealth Scan at 13:16, 23.84s elapsed (65535 total ports)
Nmap scan report for 192.168.1.1
Host is up (0.039s latency).
Not shown: 65520 closed ports
PORT      STATE    SERVICE
21/tcp    open     ftp
22/tcp    filtered ssh
23/tcp    filtered telnet
53/tcp    open     domain
80/tcp    open     http
139/tcp   open     netbios-ssn
445/tcp   open     microsoft-ds
631/tcp   open     ipp
8080/tcp  open     http-proxy
17998/tcp open     unknown
32768/tcp open     filenet-tms
37443/tcp open     unknown
37444/tcp open     unknown
49652/tcp open     unknown
49653/tcp open     unknown

Read data files from: /usr/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 25.57 seconds
           Raw packets sent: 65726 (2.892MB) | Rcvd: 65679 (2.627MB)
root@momen-PC:~#
```

nmap扫描开放端口

在用户主目录打开`.ssh`目录
创建ssh key文件
`ssh-keygen -t rsa -C "youremail@example.com"`
复制`id_rsa.pub`公钥内信息，保存好id_rsa私钥
打开github，填入sshkey信息 
https://github.com/settings/keys
即可