自搞知识点

awk -F: '{shells[$NF]++}END{for(i in shells)print i,shells[i]}' /etc/passwd

awk -F: '{if($3==0){a++} else if($3>0&&$3<1000){b++} else{c++}}END{print "管理员个数:"a,"\n虚拟用户个数:"b,"\n普通用户个数:"c}' /etc/passwd

awk 'BEGIN{print 100*100}'

ps axuf|awk '{print $5}'|grep -v VSZ|tr "\n" "+"|sed -r 's#(.*)#\10\n#g'

ps axuf|awk '{print $5}'|grep -v VSZ|tr "\n" "+"|sed -r 's#(.*)#\10\n#g'|bc

ps axuf|awk '{print $5}'|grep -v VSZ|awk '{sum+=$1}END{print sum}'

sed 's#[:/0-9x]# #g' /etc/passwd|xargs -n1|sort |uniq -c|sort -rn|head

sed 's#[:/0-9]# #g' /etc/passwd|xargs -n1|awk '{count[$1]++}END{for(i in count) print i,count[i]}'|awk '{print $2,$1}'|sort -rn|head|grep -v x

ifconfig eth0|awk 'NR==2{print $2}'|xargs mkdir /home/