几个不错的Shell脚本

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

#!/bin/bash read -p Enter a number or string here: input case $input in [0⑼]) echo -e Good job,Your input is a numberic! ;; [a-zA-Z]) echo -e Good job,Your input is a character! ;; *) echo -e Your input is wrong,input again! ;; esac

【例子:002】求平均数

#!/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 [0⑴00%] ('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

[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

# 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】批量测试文件是不是存在

[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.

】用指定大小文件填充硬盘

[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 date= $(date) fi mkdir -p /tmp/temp cat < testfile > /tmp/temp/myfile.$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

[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】简单正则表达式利用

[root@host ~]# cat regex.sh #!/bin/env sh #Filename: regex.sh regex=[A-Za-z0⑼]{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($1,/^-?[0⑼]+$/);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