do
a=$(($a+1))
if test $a -gt 255
then break
else
echo $(ping -c 1 192.168.0.$a | grep "ttl" | awk '{print $4}'| sed 's/://g')
ip=$(ping -c 1 192.168.0.$a | grep "ttl" | awk '{print $4}'| sed 's/://g')
echo $ip >> ip.txt
fi
done
19.打印当前用户
#/bin/bash
echo "Current User is :"
echo $(ps | grep "$$" | awk '{print $2}')
20.case语句练习
#!/bin/bash
clear
echo "enter a number from 1 to 5:"
read num
case $num in
1) echo "you enter 1"
;;
2) echo "you enter 2"
;;
3) echo "you enter 3"
;;
4) echo "you enter 4"
;;
5) echo "you enter 5"
;;
*) echo "error"
;;
esac
21.yes/no返回不同的结构
#!/bin/bash
clear
echo "enter [y/n]:"
read a
case $a in
y|Y|Yes|YES) echo "you enter $a"
;;
n|N|NO|no) echo "you enter $a"
;;
*) echo "error"
;;
esac
22.内置命令的使用
#/bin/bash
clear
echo "Hello, $USER"
echo
echo "Today 's date id `date`"
echo
echo "the user is :"
who
echo
echo "this is `uname -s`"
echo
echo "that's all folks! "
23.打印无密码用户
#/bin/bash
echo "No Password User are :"
echo $(cat /etc/shadow | grep "!!" | awk 'BEGIN { FS=":" }{print $1}')
24.
#/bin/bash
clear
echo "Hello, $USER"
echo
echo "Today 's date id `date`"
echo
