linux下shell脚本中的语句
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2022-03-15 23:21:53
...
exit 退出该脚本
break 退出循环,但循环之后的命令依旧会执行
continue 退出本次循环语句,词语句后循环的语句依旧会执行,
for语句的基本结构
for
do
done
seq 可以设置步长,可以引用变量
ping主机是否通并显示通的?
#!/bin/bash
for i in {70..110}
do
ping -c1 -w1 172.25.254.$i &>/dev/null && echo "172.25.254.$i"
done
数据库备份?
#!/bin/bash
TABASE_MESSAGE=`mysql -uroot -predhat -EN -e "show databases;" | grep -E "^\*|schema$" -v`
mkdir -p /mnt/mysql_dump
for DATABASE_NAME in $DATABASE_MESSAGE
do
mysqldump -uroot $DATABASE_NAME > /mnt/mysql_dump/${DATABASE_NAME}.sql
[ "$?" -eq "0" ]&&{
echo -e "\033[32m$DATABASE_NAME is backuped !!\033[0m"
}
done
2.whlie done语句
动态监控CPU负载?
while true
do
echo -n `uptime`
echo -ne "\r \r"
sleep 1
done
根分区容量超过10%时给root用户发邮件报警?
#!/bin/bash
Use=`df | awk -F " " '/\/$/{print $5}'| awk -F "%" '{print $1}'`
while true
do
[ "$Use" -ge "10" ]&&{
echo "your / will full" | mail -s warning root
}
sleep 1
done
根分区容量超过10%时将报警显示在当前shell上?
#!/bin/bash
Use=`df | awk -F " " '/\/$/{print $5}' | awk -F "%" '{print $1}'`
TTY=`ps | awk '/bash$/{print $2}'`
while true
do
[ "$Use" -ge 10 ]&&{
echo "your / will full !!" > /dev/$TTY
}
sleep 5
done