version: "1.0.0"

linux skill

netcat

listen port udp keep nc -lp 8888 nc -lup 8888 nc -lk 8888

ps -ef | grep nc ll /proc/231707/fd IO Multiplexing io多路复用

用户管理

/etc/passwd /etc/group cat /etc/shadow useradd usermod groupadd groupdel gpasswd groups id passwd

useradd luoxue userdel luoxue tail -n 5 /etc/{passwd,group,shadow} useradd u2 -s /bin/bash -m useradd u3 -s /bin/bash -m -g root useradd u4 -s /bin/bash -m -G root -p u4 usermod -g root u4 gpasswd -a luoxue root gpasswd -M luoxue,user1 root groups luoxue id luoxue