Linux shell 脚本实例

1. 写一个脚本，利用循环计算10的阶乘#!/bin/sh

factorial=1
for a in `seq 1 10`
do
factorial=`expr $factorial \* $a`
done
echo "10! = $factorial"

2. 写一个脚本，执行后，打印一行提示“Please input a number:"，要求用户输入数值，然后打印出该数值，然后再次要求用户输入数值。直到用户输入"end"停止。

[root@localhost bak]# cat 11.sh
#!/bin/bash
while true
do
read -p "please input a number and input key {end} to exit: " var
if [  $var = "end"  ];then
exit
fi
echo "your input number is $var"
done
[root@localhost bak]# bash 11.sh
please input a number and input key {end} to exit: 11
your input number is 11
please input a number and input key {end} to exit: 22
your input number is 22
please input a number and input key {end} to exit: end

3. 写一个脚本，利用循环和continue关键字，计算100以内能被3整除的数之和

#!/bin/bash
sum=0
for i in `seq 1 100`
do
a=$(($i%3))
if [ $a -eq 0 ];then
sum=`expr $sum + $i`
fi
continue
done
echo "100以内能被3整除的数之和: "$sum

4．一个函数，利用shift计算所有参数乘积，假设参数均为整数

[root@localhost bak]# cat 13.sh
#! /bin/sh
result=1
while [ $# -gt 0 ]
do
result=`expr $result \* $1`
shift
done
echo $result
[root@localhost bak]# bash 13.sh 2 3 5 20
600

5．写一个脚本，可以根据参数文件名，以正确的参数调用tar来解压缩tar.gz或tar.bz2文件。

#!/bin/sh
case ${1##*.tar} in
bz2)
tar jxvf $1
;;
gz)
tar zxvf $1
;;
*)
echo "wrong file type"
esac

6．写一个脚本以方便用户查询rpm的相关信息。这个脚本首先提示用户选择查询依据，比如文件名，包名，全部等。然后提示用户选择查询信息，比如包名，包里所包含的所有文件，包的信息等。然后询问是否继续查询，是则循环刚才的过程，否则退出。

#!/bin/bash
# favourite OS. samli 2004.4.19
echo "What is your favourite OS?"
select var in "Linux" "UNIX" "Windows" "Other"; do
echo "You have selected $var."
#break
done

# !/bin/bash
# list a content summary of a number of RPM packages samli 2004.4.19
# USAGE: showrpm rpmfile1 rpmfile2 ...
# EXAMPLE: showrpm /cdrom/Thizlinux/RPMS/*.rpmfor rpmpackage in $*;
do
if [ -r "$rpmpackage" ];
then
echo "=============== $rpmpackage =============="
/bin/rpm -qip $rpmpackage
else
echo "ERROR: cannot read file $rpmpackage"
fi
done#!/bin/bash
if [ $# -le 0 ]
then
echo "Not enough parameters"
exit 1
fi
#string="2 3 4 5 6"
#set string
sum=0
while [ $# -gt 0 ]
do
sum=`expr $sum + $1`
shift
done
echo $sum#! /bin/bash
echo "*******************************"
echo "Please select your operation:"
echo " 1 Copy"
echo " 2 Delete"
echo " 3 Backup"
echo "*******************************"
read op
case $op in
C)
echo "your selection is Copy"
;;
D)
echo "your selection is Delete"
;;
B)
echo "your selection is Backup"
;;
*)
echo "invalid selection"
esac
#! /bin/sh
while true
do
echo "*******************************"
echo "Please select your operation:"
echo " 1 Copy"
echo " 2 Delete"
echo " 3 Backup"
echo " 4 Quit"
echo "*******************************"
read op
case $op in
C)
echo "your selection is Copy"
;;
D)
echo "your selection is Delete"
;;
B)
echo "your selection is Backup"
;;
Q)
echo "Exit ..."
break
;;
*)
echo "invalid selection,please try again"
esac
done
#! /bin/sh
a=10
b=20
c=30
value1=`expr $a + $b + $c`
echo "The value of value1 is $value1"
value2=`expr $c / $b`
echo "The value of value2 is $value2"
value3=`expr $c * $b`
echo "The value of value3 is $value3"
value4=`expr $a + $c / $b`
echo "The value of value4 is $value4"
var4=`expr $value4 - $value2`
echo $var4
#! /bin/sh
sum=0
for i in $*
do
sum=`expr $sum + $i`
done
echo $sum
abc=123
echo $abc
###定义函数example1(){abc=456}###调用函数example1echo $abcabc=234234example1echo $abc###定义函数，使用参数example2(){echo $1echo $2}
###调用函数,向它传递参数example2 abc bbbexample2 dksdfsdfsfaa bbb#!/bin/bash
echo "please input a file name:"
read file_name
if [ -d $file_name ]
then
echo "$file_name is a directory"
elif [ -f $file_name ]
then
echo "$file_name is a regular file"
elif [ -c $file_name -o -b $file_name ]
then
echo "$file_name is a device file"
else
echo "$file_name is an unkonwn file"
fi
#! /bin/sh
read first second third
echo "the first parameter is $first"
echo "the second parameter is $second"
echo "the third parameter is $third"
#! /bin/sh
if [ $# -ne 2 ]; then
echo "Not enough parameters"
exit 0
fiif [ $1 -eq $2 ]; then
echo "$1 equals $2"
elif [ $1 -lt $2 ]; then
echo "$1 less than $2"
elif [ $1 -gt $2 ]; then
echo "$1 greater than $2"
fi#clear
#:trap "" 2 18 20 24
＃e cho "***********************************************************************"
＃e cho " HI! You changed my root password"
＃e cho " This is a little punishment for you then you can use the shell"
＃e cho " You must answer my three questions and type "yes" or "no" to answer"
#
#answer="no"
#
＃e cho "***********************************************************************"
＃e cho "Please press "Enter" key to continue"
#read
#while [ $answer = "no" ]
#do
# echo
# echo "1.Are you a boy ? (yes/no)"
# read answer
#done
#
#answer="no"
#
#until [ $answer = "yes" ]
#do
# echo
# echo "2.Are you foolish ? (yes/no)"
# read answer
#done
#
#answer="no"
#
#until [ $answer = "yes" ]
#do
# echo
# echo "3.Do you love me ? (yes/no)"
# read answer
#done
#
＃e cho "***********************************************************************"
＃e cho
＃e cho "Now ! I know you are a foolish girl and you love me."
#e cho
＃e cho "So you can continue"
＃e cho
＃e cho "**************************************************************"
＃e cho
#sleep 3
＃e cho " (haha ! It is just a joke)"
i=1
echo "this time i is not equal to 4"
while [ $i -le 8 ]
do
((i=i+1))
if [ $i -eq 4 ]
then
echo "this time i is equal to 4"
continue
fi
echo "this time i is not equal to 4"
done
echo "The command is $0"
echo "The first argument is $1, the second argument is $2"
echo "The entire command is $0 $1 $2"
echo "And there are $# arguments"
echo "The end of testing"
#! /bin/sh
if [ $# -gt 1 ]
then
echo "Too many parameters"
exit 1
fiif [ $# -eq 0 ]
then
echo "Too few parameters"
exit 100
fiif [ ! -d $1 ]
then
echo "Usage : $0 directory"
exit 1
fi#for i in $1/*
#do
# if [ -x $i -a ! -d $i ]
# then
# ls $i
# fi
#done
#!/bin/shRPM=/bin/rpmoption="-q"
while truedo echo "what to query?" select var in "All" "file" "package name" do case $var in All) option=$option"a" break ;; file) echo -n "please input file name: " option=$option"f" read argument break ;; package\ name) echo -n "please input package name: " read argument break ;; *) echo "please choose between 1-3" ;; esac done
echo "what do you want to know?" select var in "location" "info" "package name" do case $var in location) option=$option"l" break ;; info) option=$option"i" break ;; package\ name) break ;; *) echo "please choose between 1-3" ;; esac done
${RPM} $option $argument
echo "continue? [yes/no]" read answer
if [ answer = "no" ] then break fidone
#!/bin/sh
sum=0
for a in `seq 1 100`
do
if [ `expr $a % 3` -ne 0 ]
then
continue
fi
echo $a
sum=`expr $sum + $a`
done
echo "sum = $sum"
#!/bin/bash
ftype=`file "$1"`
case "$ftype" in
"$1: Zip archive"*)
/usr/bin/unzip "$1" ;;
"$1: gzip compressed"*)
/bin/gunzip "$1" ;;
"$1: bzip2 compressed"*)
/usr/bin/bunzip2 "$1" ;;
*)
echo "Sorry, file $1 can not be uncompressed with smartzip." ;;
esac

注：上面有一行，for a in `seq 1 10`,其中seq 1 10 , 即列出现1到10之间所有的数字，这一行也可改为：for a in "1 2 3 4 5 6 7 8 9 10", 在用 expr 进行乘法运算时，为了避免 * 被看成匹配符，需要对其进行转义， 用 \*自动备份数据库脚本两个！MySQL：Linux下自动备份数据库的shell脚本 Linux 服务器上的程序每天都在更新 MySQL 数据库，于是就想起写一个 shell 脚本，结合 crontab，定时备份数据库。其实非常简单，主要就是使用 MySQL 自带的 mysqldump 命令。

脚本内容如下：
#!/bin/sh
# File: /home/mysql/backup.sh
# Database info
DB_NAME="test"
DB_USER="username"
DB_PASS="password"

# Others vars
BIN_DIR="/usr/local/mysql/bin"
BCK_DIR="/home/mysql/backup"
DATE=`date +%F`

# TODO
$BIN_DIR/mysqldump --opt -u$DB_USER -p$DB_PASS $DB_NAME | gzip > $BCK_DIR/db_$DATE.gz

然后使用将此脚本加到 /etc/crontab 定时任务中：

01 5 * * 0 mysql /home/mysql/backup.sh

好了，每周日凌晨 5:01 系统就会自动运行 backup.sh 文件备份 MySQL 数据库了。

/home/www/inc/back
第二个！！！！#!/bin/sh

# File: /home/mysql/backup.sh

# Database info bakupmysql

DB_USER="user"

DB_PASS="password"

# Others vars

DATE=`date +%Y-%m-%d`

mkdir /home/mysqlbak/$DATE

BIN_DIR="/usr/local/mysql/bin"

BCK_DIR="/home/mysqlbak/$DATE"

# TODO

$BIN_DIR/mysqldump --opt -u$DB_USER -p$DB_PASS discuz > $BCK_DIR/discuz.sql

$BIN_DIR/mysqldump --opt -u$DB_USER -p$DB_PASS zjblog > $BCK_DIR/zjblog.sql

$BIN_DIR/mysqldump --opt -u$DB_USER -p$DB_PASS openads > $BCK_DIR/openads.sql

写脚本实现，可以用shell、perl等。在目录/tmp下找到100个以abc开头的文件，然后把这些文件的第一行保存到文件new中。参考答案1：#!/bin/sh
for filename in `find /tmp -type f -name "abc*"|head -n 100`
do
sed -n '1p' $filename>>new
done
解析：第一，用到了find命令，其中-type f表示选取普通文件，-name用于设定文件名；第二，head -n 100命令用于取出前100项。第三，sed -n ’1p’用于取出文件的第一行内容。第四，>>new表示追加到文件new中。参考答案2：

find /tmp -type f -name “abc*” | head -n 100 | xargs head -q -n 1 >> new

方法二：

2）写脚本实现，可以用shell、perl等。把文件b中有的，但是文件a中没有的所有行，保存为文件c，并统计c的行数。

参考答案：

grep -vxFf a b | tee c | wc -l

解析：grep选取-v表示不选择匹配的行，-F表示匹配的模式按行分割，-f a表示匹配模式来自文件a，最后表示目标文件b。即grep命令从b中选取a中不存在的行。 tee c命令创建文件c，wc -l命令统计行数。