文章內容

bash編程入門

發布時間: 2012/9/15 18:03:46

1. ping 主機

#!/bin/bash

HOSTNAME=$1 #注意位置參數的使用 if ping -c2 $HOSTNAME;then

echo "The $HOSTNAME is online."

else

echo "The $HOSTNAME is down."

==================================================================

2.找文件—》找到就備份—》沒找到就顯示其他信息

#!/bin/bash

DIR=$1

BACKUP=$2

#destination of the backup.

if [ ! -d $2 ] ;then

echo "The directory does not exist!"

elif [ $# -eq 2 ];then

echo "$DIR is backuped to $BACKUP... "

else

echo -e "Usage: $0 dir backupfile\n for example:$0 /etc/passwd /tmp/bash"

==================================================================

3.找用戶—>并統計行數—>

#!/bin/bash

USERNAME=$1

RES=$(cat /etc/passwd | grep $USERNAME | wc -l)

if [ "$RES" == "1" ] ;then

echo "The user you want to find is $USERNAME."

elif [ $RES -eq 0 ];then

echo "The user you want to find doesnot exist."

else

echo "Some other errors happen"

==================================================================

4.查看文件是否存在并且可寫

#!/bin/bash

if [ -f $1 -a -w $1 ];then

echo "The file is writable."

else

echo "This a directory."

==================================================================

5.簡單的if-else嵌套

#!/bin/bash

HOST=$1

if ping -c2 $HOST &> /dev/null ;then

echo "$HOST is online. "

else

echo "$HOST is down."

==================================================================

6.第5個程序可改寫如下：

#!/bin/bash

HOST=$1

ping -c2 $HOST &> /dev/null && echo "$HOST is online " || echo "$HOST is down"

==================================================================

7.查看文件夾是否可寫可執行

#!/bin/bash

DIR=$1

[ -r $DIR ] && echo "The file is readable" || echo "The directory is not readable"

[ -w $DIR ] && echo "The file is writable" || echo "The file is not writable"

[ -x $DIR ] && echo "The file is excutable" || echo "The file is not excutable"

==================================================================

8．簡單的菜單選項設置

#!/bin/bash

echo "======================="

echo -e "\t\t1.Linux"

echo -e "\t\t2.Unix"

echo -e "\t\t3.Windows"

echo "======================="

read NUMBER

if [ $NUMBER -eq 1 ];then

echo "You have chosen RedHad Linux 6.0"

elif [ $NUMBER -eq 2 ];then

echo "You have chosen IBM AIX"

elif [ $NUMBER -eq 3 ];then

echo "You have chosen Windows!"

else

echo "You have chosen a wrong number!"

==================================================================

9．簡單退出值的設定

#!/bin/bash

FILENAME=$1

if [ -d $FILENAME ];then

echo "this is a directory!"

exit 10

elif [ ! -w $FILENAME ];then

exit 20

else

exit 1

==================================================================

10．case的用法（模擬服務的啟動）

把寫好的腳本加入到 /etc/rc.d/init.d并注意加上著色幾行，并用命令

Chkconfig —add SERVICENAME

#!/bin/bash

# chkconfig: 235 90 12

# description:

if [ $# -lt 1 ];then

echo "Usages: services $1 {start|stop|restart|status}"

else

case "$2" in

start)

echo "The service $1 is starting"

;;

stop)

echo "The service $1 is stopping"

;;

restart)

echo -e "The servie $1 is stopping\nThe service is starting"

;;

status)

echo "The service $1's status is..."

;;

esac

==================================================================

11.用source和bash調用程序的時候，返回值不同。

○ 1

#!/bin/bash

bash ./b.sh

RES=$?

echo "The $0 pid is $$"

case "$RES" in

10)

echo "Network problem"

;;

20)

echo "Directory does not exist"

;;

esac

○ 2

#!/bin/bash

echo " The $0 pid is $$"

exit 10

==================================================================

12.for循環中的變量字符集

#!/bin/bash

for HOST in 172.24.254.254 172.24.254.200 172.24.123.123

ping -c2 $HOST &> /dev/null && echo "$HOST is online" \

|| echo "$HOST is down"

done

==================================================================

13.for循環變量字符集

#!/bin/bash

for HOST in 172.24.0.{1..10}

ping -c2 $HOST &> /dev/null && echo "$HOST is online" \

|| echo "$HOST is down"

Done

==================================================================

14.for循環變量文件集

#!/bin/bash

for FILE in /etc/*.conf

cp $FILE /tmp/tmp

done

#!/bin/bash

DEST=/var/tmp

for FILENAME in /lib64/*.* /etc/*.conf

cp $FILENAME $DEST &> /dev/null

logger "backup $FILENAME now..."

echo "Backup $FILENAME TO $DEST" >> ~/backup.log

done

==================================================================

15.for循環指令集

#!/bin/bash

for USERINFO in $(cat /etc/passwd | grep bash$ | cut -d: \

-f1,3)

_USENAME=$(echo $USERINFO | cut -d: -f 1)

_UID=$(echo $USERINFO | cut -d: -f 2)

if [ $_UID -lt 500 -a $_UID -ne 0 ];then

logger "$_USERNAME is a system user ,but can \

log now"

done

==================================================================

16.輸出9*9乘法表

#!/bin/bash

for NUM1 in {1..9}

for NUM2 in {1..9}

RES=$((NUM1 * NUM2))

echo -en "$NUM1 * $NUM2 = $RES\t"

done

echo

done

==================================================================

17.輸出9*9乘法表

#!/bin/bash

for ((i=1;i<10;i++))

for ((p=1;p<=i;p++))

RES=$(($p * $i))

echo -en "$p * $i = $RES\t"

done

echo

done

echo

==================================================================

18.輸出黑白象棋

#!/bin/bash

for HANG in {1..9}

for LIE in {1..9}

RES=$((HANG + LIE))

if [ $(($RES % 2)) -eq 0 ];then

echo -en "\033[47m \033[0m"

else

echo -en "\033[40m \033[0m"

done

echo

done

==================================================================

19.輸出黑白象棋

#!/bin/bash

for HANG in {1..9}

for LIE in {1..9}

RES=$((HANG + LIE))

if ((($RES % 2) == 0)) ;then

echo -en "\033[47m \033[0m"

else

echo -en "\033[40m \033[0m"

done

echo

done

==================================================================

20.輸出數字形狀

#!/bin/bash

echo "Please type your number:"

read a

for ((i=1;i<=a;i++))

for ((p=1;p<=i;p++))

echo -n "$p"

done

echo

done

echo

==================================================================

21.計算器（加減乘除）

echo "..............x"

echo "............../"

echo "..............q"

echo "Please type your word:(e.g.1 + 2)"

read a b c

case $b in

+) echo " $a + $c =" `expr $a + $c`;;

-) echo " $a - $c =" `expr $a - $c`;;

x) echo " $a x $c =" `expr $a \* $c`;;

/) echo " $a / $c =" `expr $a \/ $c`;;

esac

case $a in

q) break ;;

esac

done

==================================================================

22.輸出直角三角形

#!/bin/bash

echo "Please type a number:"

read num

for ((i=1;i<num;i++))

for ((j=0;j<num-i;j++))

echo -n ""

done

for ((j=0;j<2*i-1;j++))

echo -n "*"

done

==================================================================

23.輸出翻轉三角形

#!/bin/bash

echo "Please type a number:"

read num

for ((i=1;i<num;i++))

for ((j=0;j<num-i;j++))

echo -n ""

done

for ((j=0;j<2*i-1;j++))

echo -n "*"

done

echo ""

done

for ((i=1;i<=num;i++))

for ((j=0;j<i;j++))

echo -n ""

done

for ((j=0;j<2*(num-i)-1;j++))

echo -n "*"

done

echo ""

done

==================================================================

24.菜單的設定

!/bin/bash

while [[ "$CHOOSE" != "q" && "$CHOOSE" != "Q" ]]

clear

echo "1.Linux"

echo "2.Unix"

echo "q.quit"

read CHOOSE

case $CHOOSE in

echo "You have chosen Linux"

exit 10

;;

echo "You have chosen Uinx"

exit 20

;;

esac

done

==================================================================

25.簡單函數，函數可接受位置參數，此函數名字為24.sh

#!/bin/bash

clean_tmp_file()

{

echo "clean $1..."

}

#$1 is a dabase name and $2 is a folder

backup_database()

{

echo "backup database $1 to $2"

}

check_file_md5()

{

echo "check $1 sum md5 value"

}

clean_tmp_file /tmp/empty

==================================================================

26.調用函數庫中的函數

#!/bin/bash

source ./24.sh

clean_tmp_file /etc/passwd

check_file_md5 /etc/group

backup_database /mys

==================================================================

27.路徑的設置

#!/bin/bash

setPath ()

{

PATH=/bin:/usr/bin

if [ $UID -eq 0 ];then #如果是root用戶

PATH=$PATH:/usr/bin/sbin:/sbin #路徑追加sbin的目錄

if (($2 == "after"));then #根據位置參數2，決定如何添加新路徑

PATH=$PATH:$1 #在原PATH后面追加

else

PATH=$1:$PATH #在原PATH之前添加

}

本文出自：億恩科技【www.endtimedelusion.com】

服務器租用/服務器托管中國五強！虛擬主機域名注冊頂級提供商！15年品質保障！--億恩科技[ENKJ.COM]

服務器租用

服務器托管

機柜批發

云服務器

建站俠

空間/域名

安全保姆

幫助類別

幫助中心

文章內容

bash編程入門

同類文章

億恩公告

在線客服