head -c 17 | tail -c 1
		

			
printf "%s" $(printf '\033[0;31m'); tail /etc/passwd
			
			

			
tail -f example.log | sed \
-e "s/FATAL/"$'\e[31m'"&"$'\e[m'"/" \
-e "s/ERROR/"$'\e[31m'"&"$'\e[m'"/" \
-e "s/WARNING/"$'\e[33m'"&"$'\e[m'"/" \
-e "s/INFO/"$'\e[32m'"&"$'\e[m'"/" \
-e "s/DEBUG/"$'\e[34m'"&"$'\e[m'"/"
			
			

首先看看源文件内容

			
[root@netkiller ~]# head -n 5 /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
			
			

现在跳过第一行，显示后面所有内容

			
[root@netkiller ~]# tail -n +2 /etc/passwd
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:65534:65534:Kernel Overflow User:/:/sbin/nologin
systemd-coredump:x:999:996:systemd Core Dumper:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
tss:x:59:59:Account used for TPM access:/dev/null:/sbin/nologin
polkitd:x:998:995:User for polkitd:/:/sbin/nologin
sssd:x:997:994:User for sssd:/:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/usr/share/empty.sshd:/sbin/nologin
systemd-oom:x:992:992:systemd Userspace OOM Killer:/:/usr/sbin/nologin
mysql:x:27:27:MySQL Server:/var/lib/mysql:/sbin/nologin
chrony:x:991:991::/var/lib/chrony:/sbin/nologin
docker:x:990:990:Container Administrator:/home/docker:/bin/bash
			
			

			
[root@netkiller ~]# nmap -F 121.196.46.109
Starting Nmap 7.91 ( https://nmap.org ) at 2022-08-01 14:52 CST
Nmap scan report for 121.196.46.109
Host is up (0.016s latency).
Not shown: 97 filtered ports
PORT     STATE  SERVICE
113/tcp  closed ident
2000/tcp open   cisco-sccp
5060/tcp open   sip

Nmap done: 1 IP address (1 host up) scanned in 4.38 seconds
[root@netkiller ~]# nmap -F 121.196.46.109 | tail -n +5
PORT     STATE  SERVICE
113/tcp  closed ident
2000/tcp open   cisco-sccp
5060/tcp open   sip

Nmap done: 1 IP address (1 host up) scanned in 1.83 seconds
[root@netkiller ~]# nmap -F 121.196.46.109 | tail -n +5 | head -n -1
PORT     STATE  SERVICE
113/tcp  closed ident
2000/tcp open   cisco-sccp
5060/tcp open   sip