8个实用的Shell脚本分享
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2023-02-13 23:23:19
几个shell脚本的例子，觉得还不错。
【例子:001】判断输入为数字，字符或其他
复制代码 代码如下:
#!/bin/bash
read -p "e...
几个shell脚本的例子，觉得还不错。
【例子:001】判断输入为数字，字符或其他
复制代码 代码如下:
#!/bin/bash
read -p "enter a number or string here:" input
case $input in
[0-9]) echo -e "good job, your input is a numberic! \n" ;;
[a-za-z]) echo -e "good job, your input is a character! \n" ;;
*) echo -e "your input is wrong, input again! \n" ;;
esac
【例子:002】求平均数
复制代码 代码如下:
#!/bin/bash
# calculate the average of a series of numbers.
score="0"
average="0"
sum="0"
num="0"
while true; do
echo -n "enter your score [0-100%] ('q' for quit): "; read score;
if (("$score" < "0")) || (("$score" > "100")); then
echo "be serious. common, try again: "
elif [ "$score" == "q" ]; then
echo "average rating: $average%."
break
else
sum=$[$sum + $score]
num=$[$num + 1]
average=$[$sum / $num]
fi
done
echo "exiting."
【例子:003】自减输出
复制代码 代码如下:
[scriptname: doit.sh]
while (( $# > 0 ))
do
echo $*
shift
done
/> ./doit.sh a b c d e
a b c d e
b c d e
c d e
d e
e
【例子:004】在文件中添加前缀
复制代码 代码如下:
# 人名列表
# cat namelist
jame
bob
tom
jerry
sherry
alice
john
# 脚本程序
# cat namelist.sh
#!/bin/bash
for name in $(cat namelist)
do
echo "name= " $name
done
echo "the name is out of namelist file"
# 输出结果
# ./namelist.sh
name= jame
name= bob
name= tom
name= jerry
name= sherry
name= alice
name= john
【例子:005】批量测试文件是否存在
复制代码 代码如下:
[root@host ~]# cat testfile.sh
#!/bin/bash
for file in test*.sh
do
if [ -f $file ];then
echo "$file existed."
fi
done
[root@host ~]# ./testfile.sh
test.sh existed.
test1.sh existed.
test2.sh existed.
test3.sh existed.
test4.sh existed.
test5.sh existed.
test78.sh existed.
test_dev_null.sh existed.
testfile.sh existed.
【例子:005】用指定大小文件填充硬盘
复制代码 代码如下:
[root@host ~]# df -ih /tmp
filesystem inodes iused ifree iuse% mounted on
/dev/mapper/vg00-lvol5
1000k 3.8k 997k 1% /tmp
[root@host ~]# cat cover_disk.sh
#!/bin/env bash
counter=0
max=3800
remainder=0
while true
do
((counter=counter+1))
if [ ${#counter} -gt $max ];then
break
fi
((remainder=counter%1000))
if [ $remainder -eq 0 ];then
echo -e "counter=$counter\tdate=" $(date)
fi
mkdir -p /tmp/temp
cat < testfile > "/tmp/temp/myfile.$counter"
if [ $? -ne 0 ];then
echo "failed to write file to disk."
exit 1
fi
done
echo "done!"
[root@host ~]# ./cover_disk.sh
counter=1000 date= wed sep 10 09:20:39 hkt 2014
counter=2000 date= wed sep 10 09:20:48 hkt 2014
counter=3000 date= wed sep 10 09:20:56 hkt 2014
cat: write error: no space left on device
failed to write file to disk.
dd if=/dev/zero of=testfile bs=1m count=1
【例子:006】通过遍历的方法读取配置文件
复制代码 代码如下:
[root@host ~]# cat hosts.allow
127.0.0.1
127.0.0.2
127.0.0.3
127.0.0.4
127.0.0.5
127.0.0.6
127.0.0.7
127.0.0.8
127.0.0.9
[root@host ~]# cat readlines.sh
#!/bin/env bash
i=0
while read line;do
hosts_allow[$i]=$line
((i++))
done < hosts.allow
for ((i=1;i<=${#hosts_allow[@]};i++)); do
echo ${hosts_allow[$i]}
done
echo "done"
[root@host ~]# ./readlines.sh
127.0.0.2
127.0.0.3
127.0.0.4
127.0.0.5
127.0.0.6
127.0.0.7
127.0.0.8
127.0.0.9
done
【例子:007】简单正则表达式应用
复制代码 代码如下:
[root@host ~]# cat regex.sh
#!/bin/env sh
#filename: regex.sh
regex="[a-za-z0-9]{6}"
if [[ $1 =~ $regex ]]
then
num=$1
echo $num
else
echo "invalid entry"
exit 1
fi
[root@host ~]# ./regex.sh 123abc
123abc
#!/bin/env bash
#filename: validint.sh
validint(){
ret=`echo $1 | awk '{start = match($1,/^-?[0-9]+$/);if (start == 0) print "1";else print "0"}'`
return $ret
}
validint $1
if [ $? -ne 0 ]; then
echo "wrong entry"
exit 1
else
echo "ok! input number is:" $1
fi
【例子:008】简单的按日期备份文件
复制代码 代码如下:
#!/bin/bash
now=$(date +"%m-%d-%y") # 当前日期
file="backup.$now.tar.gz" # 备份文件
echo "backing up data to /tmp/backup.$now.tar.gz file, please wait..." #打印信息
tar xcvf /tmp/backup.$now.tar.gz /home/ /etc/ /var # 同时备份多个文件到指定的tar压缩文件中
echo "done..."