• linux之shell脚本练习

    以下脚本已经是在ubuntu下测试的

    demo持续更新中。。。

    1、for 循环测试，，，Ping 局域网

    1. #!/bin/bash
    2.  
    3. i=1
    4. for i in {1..254}
    5. do
    6.     # 每隔0.3s Ping 一次，每次超时时间3s，Ping的结果直接废弃
    7. 	ping-w 3 -i 0.3 192.168.110.$i > /dev/null
    8. 	if [ $? -eq 0  ];then
    9. 		echo "192.168.120.$i is rechable"
    10. 	else
    11. 		echo "192.168.120.$i is unrechable"
    12. 	fi
    13. 	#let i++
    14. done

    2、批量添加用户

    1. #!/bin/bash
    2.  
    3. user=$(cat /opt/user.txt)
    4.  
    5. for i in $user
    6. do
    7. 	echo "$i"
    8. 	useradd "$i"
    9. 	echo $i:$i | chpasswd
    10. 	#echo "1234" | passwd --stdin $i
    11. done

    注意点：

    • ubuntu 不支持--stdin，要用echo 和 chpasswd结合使用
    • 在ubuntu 上要使用$(cat /opt/user.txt)，而不是$`cat /opt/user.txt`, 否则通过for 循环遍历时，第一个数据老是给加上$，比如user.txt第一行的数据是user1,它会变成$user1, 

    有批量添加，就有批量删除

    1. #!/bin/bash
    2.  
    3. user=$(cat /opt/user.txt)
    4.  
    5. for i in $user 
    6. do
    7. 	userdel -f $i
    8. done

    3、将1-100中的奇数放入数组

    1. #!/bin/bash
    2.  
    3. for((i=0;i<=100;i++))
    4. do
    5. 	if [ $[i%2] -eq 1 ];then
    6. 		array[$[$[$i-1]/2]]=$i
    7. 	fi
    8. done
    9. #echo ${array[0]}
    10. echo ${array[*]}

    运行结果

    1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99

    知识点： 

    • $[] 是用来进行数学运算的，支持+、-、*、%、/。效果同$(())
    • $[] 中括号里引用的变量可以不用加$符号，比如上面的 $[i%2]
    • $[i%2]等同于$((i%2))
    • array[*] 表示获取数组中的所有数据

    4、创建任意数字及长度的数组，自定义元素

    1. #!/bin/bash
    2.  
    3. i=0
    4.  
    5. while true
    6. do
    7. 	read -p  "input? yes or no:" operate
    8. 	if [ $operate = no ];then
    9. 		break
    10. 	fi
    11. 	read -p "input the value：" value
    12. 	array[$i]=$value
    13. 	let i++
    14. done
    15.  
    16. echo ${array[*]}

    知识点：

    • [ $doing = no ] 等价于[ $doing = "no" ] , = 是判断字符串的，对于纯字符串所以加不加引号都可

    5、将数组中的数小于60的变成60，高于60的不操作

    1. #!/bin/bash
    2.  
    3. array=(61 62 63 50 59 64)
    4. count=${#array[*]}
    5.  
    6. echo before:${array[*]}
    7. for((i=0;i<$count;i++))
    8. do
    9. if [ ${array[$i]} -lt 60 ] ; then
    10. 	array[$i]=60
    11. fi
    12. done
    13.  
    14. echo after:${array[*]}

    知识点：

    • 数组的定义中的元素之间用空格分开，不要用逗号（,）
    • 数组的长度用 ${#array[*]} 或 ${#array[@]} 获取
    • 数组元素的获取用 ${array[0]} , 赋值的时候不用加$ {}

    6、判断数组中最大的数

    1. #!/bin/bash
    2.  
    3. max=0
    4. array=(1 2 5 3 7 9)
    5. count=${#array[*]}
    6.  
    7. for((i=0;i<$count;i++))
    8. do
    9. 	if [ ${array[$i]} -gt $max ];then
    10. 		max=${array[$i]}
    11. 	fi
    12. done
    13.  
    14. echo "the max num of array is ${max}"

    知识点：

    •  在取变量的时候需要加$，比如：$max, ${array[0]}，再给变量赋值的时候不需要加$比如：max=1, array[0]=1

    7、猜数字

    1. #!/bin/bash
    2.  
    3. seed=(0 1 2 3 4 5 6 7 8 9)
    4. len=${#seed[*]}
    5. random=$[RANDOM%$len]
    6. guess=${seed[$random]}
    7.  
    8. while :
    9. do
    10. 	read -p "0-9?  you guess which one? " doing
    11. 	if [ $doing -eq $guess  ]; then
    12. 		echo "bingo"
    13.         exit 0
    14. 	elif [ $doing -gt $guess  ]; then
    15. 		echo "oops, too big"
    16. 	else 
    17. 		echo "oops, too small"
    18. 	fi
    19. 	
    20. done
    21.

    知识点

    • $RANDOM 的范围是 [0, 32767] 
    • ：空语句相当于true，即 while : 相当于 while true

    8、删除数组中小于60的元素（unset）

    1. #!/bin/bash
    2.  
    3. num=(58 59 60 61 62)
    4.  
    5. i=0
    6. for p in ${num[*]}
    7. do
    8. 	if [ $p -lt 60 ]; then
    9. 		unset num[$i]
    10. 	fi
    11. 	let i++
    12. done
    13.  
    14. echo the final result is ${num[*]}
    15. exit 0

    知识点：

    • unset 为 shell 内建指令，用于删除定义的可读可写的shell变量（包括环境变量）和shell函数。不能对只读操作。
    1. tt=1
    2. echo $tt
    3. unset tt
    4. echo $tt

    9、求1...100的和

    1. #!/bin/bash
    2.  
    3. sum=0
    4. for i in {1..100} 
    5. do
    6. 	sum=$[$sum+$i]
    7. done
    8.  
    9. echo the result is ${sum}
    10. exit 0

    10、求1...50的和（until）

    1. #!/bin/bash
    2.  
    3. sum=0
    4. i=0
    5.  
    6. until [ $i -gt 50 ]
    7. do
    8. 	#sum=$[$sum+$i]
    9. 	let sum+=$i
    10. 	let i++
    11. done
    12.  
    13. echo the result is ${sum}

    知识点：

    • let 命令是 BASH 中用于计算的工具，用于执行一个或多个表达式，变量计算中不需要加上 $ 来表示变量。如果表达式中包含了空格或其他特殊字符，则必须引起来。

    11、石头,剪刀,布

    1. #!/bin/bash
    2.  
    3. game=(rock paper sissor)
    4. random=$[$RANDOM%3]
    5. scriptResult=${game[$random]}
    6.  
    7. echo $scriptResult
    8.  
    9. echo "choose your result:"
    10. echo "1.rock"
    11. echo "2.paper"
    12. echo "3.sissor"
    13.  
    14. read -p "choose 1, 2 or 3: " choice
    15.  
    16. case $choice in
    17.  
    18. 	1)
    19. 		if [ $[$random+1] -eq 1 ]; then
    20. 			echo "equal"
    21. 		elif [ $[$random+1] -eq 2 ]; then
    22. 			echo "you lose"
    23. 		else
    24. 			echo "you win"
    25. 		fi
    26. 		;;
    27. 	2)
    28.  
    29. 		if [ $[$random+1] -eq 1 ]; then
    30. 			echo "you win"
    31. 		elif [ $[$random+1] -eq 2 ]; then
    32. 			echo "equal"
    33. 		else
    34. 			echo "you lose"
    35. 		fi
    36. 		;;
    37. 	3)
    38. 		if [ $[$random+1] -eq 1 ]; then
    39. 			echo "you lose"
    40. 		elif [ $[$random+1] -eq 2 ]; then
    41. 			echo "you win"
    42. 		else
    43. 			echo "equal"
    44. 		fi
    45. 		;;
    46. 	*)
    47. 		echo "wrong number"
    48. 		;;
    49.  
    50. esac
    51.  
    52.  
    53. exit 0

    12、成绩计算（小于60 不及格 85以上优秀）

    1. #!/bin/bash
    2.  
    3. while :
    4. do
    5. 	read -p "input score: " score
    6. 	if [ $score -le 100 ] && [ $score -gt 85 ]
    7. 	then
    8. 		echo "great"
    9. 	elif [[ $score -lt 85 &&  $score -ge 60 ]]; then
    10. 		echo "normal"
    11. 	else
    12. 		echo "failed"
    13. 	fi
    14. done
    15.  
    16. exit 0

    知识点：

    • [ $score -le 100 ] && [ $score -gt 85 ] 等价于 [[ $score -le 100  &&  $score -gt 85 ]] ,双中括号之间不要有空格，[[ ]] 是shell中的关键字，不是命令，单中括号[]，是test命令

    • [[ ]] 不需要注意某些细枝末节，比[]功能强大

    • [[ ]] 支持逻辑运算

    • [[ ]] 支持正则表达式

    • [[]] 关键字

    13、计算当前的内存使用百分比

    1. #!/bin/bash
    2.  
    3. mem_line=$(free -m | grep "Mem")
    4. memory_total=$(echo $mem_line | awk '{print $2}')
    5. memory_used=$(echo $mem_line | awk '{print $3}')
    6.  
    7. echo "total memory: $memory_total MiB"
    8. echo "used memory: $memory_used MiB"
    9. #echo "usage rate: $[$memory_used/$memory_total * 100]%"
    10. echo "usage rate:" $(echo $mem_line | awk '{printf("%0.2f%", $3 / $2 * 100)}')
    11.  
    12. exit 0

     知识点：

    1、free -m 命令以MiB为单位打印

    1 MiB = 1024KiB,   1MB=1000KiB

    1. man free
    2.  
    3. -m, --mebi Display the amount of memory in mebibytes.
    1.               total        used        free      shared  buff/cache   available
    2. Mem:           3876        1182        1518           3        1175        2428
    3. Swap:           923           0         923

    grep "Mem" 会将第二行（Mem开头的那行）抽取出来

    2、awk 会进行文本处理, 利用printf函数处理小数

    awk '{printf("%0.2f%", $3 / $2 * 100)}'

    14、过滤出本机ether网卡的MAC地址

    1. #!/bin/bash
    2.  
    3. eth=$(ifconfig | grep "ether" | awk '{print $2}')
    4.  
    5. echo $eth
    6.  
    7. exit 0

    思路也简单，通过ifconfig 获取ether所在行，通过awk获取对应行的第二个参数$2

    ens37: flags=4163  mtu 1500
            inet6 fe80::5e0a:f1cf:cbf8:4c2d  prefixlen 64  scopeid 0x20
            ether 00:0c:29:f6:b6:99  txqueuelen 1000  (Ethernet)
            RX packets 87  bytes 10378 (10.3 KB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 3992  bytes 720667 (720.6 KB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

    lo: flags=73  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 68614  bytes 4911600 (4.9 MB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 68614  bytes 4911600 (4.9 MB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

    15、统计/var/log有多少个文件，并显示这些文件名

    1. #!/bin/bash
    2.  
    3. count=0
    4.  
    5. for file in $(ls /var/log)
    6. do
    7. 	echo $file
    8. 	if [ -f "/var/log/${file}" ]
    9. 	then
    10. 		let count++
    11. 		echo "file name: $file"
    12. 	else
    13. 		echo "no file"
    14. 	fi
    15. done
    16.  
    17. echo "the count of files is: ${count}"
    18.  
    19. echo "the count of files is:" `find /var/log -maxdepth 1 -type f |wc -l`
    20.  
    21. exit 0

    知识点：

    •  如果上述脚本中写成 if [ -f  $file ],就算是文件也会判断失败， file要写成路径的形式，单纯一个名字都会失败，其它文档中写的没有路径，这个注意下

    16、打印字母数小于8的单词

    1. for e in `cat ./nowcoder.txt`
    2. do
    3. 	if [ ${#e} -lt 8 ];then
    4. 		echo ${e}
    5. 	fi
    6. done
    7.  
    8. exit 0

    知识点

    • ${#} 用于获取字符串或数组的长度，${#var}：字符串长度, ${#array[*]}：数组长度

    17、统计所有进程占用内存百分比的和

    统计所有进程占用内存百分比的和_牛客题霸_牛客网 (nowcoder.com)

    1. #!/bin/bash
    2.  
    3. sum=0
    4. i=0
    5. for m in `awk '{print $4}' ./nowcoder.txt`
    6. do
    7.     if [ $i -eq 0 ];then
    8.         let i++
    9.         continue
    10.     fi
    11.     r=$(echo $m | bc)
    12.     sum=$(echo $r + $sum | bc)
    13. done
    14. echo $sum | bc
    15.  
    16. exit 0

    知识点：

    • 利用bc处理小数，这里是利用的+，，$(echo $r + $sum | bc)

    18、统计每个单词出现的个数

    打印无顺序（利用字典）

    1. #!/bin/bash
    2.  
    3. declare -A dic
    4.  
    5. for word in `cat nowcoder.txt`
    6. do
    7.     if [ $word = "" ];then
    8.         continue
    9.     fi
    10.     if [ -v dic[$word] ]; then
    11.         r=${dic[$word]}
    12.         dic[$word]=`expr $r + 1`
    13.     else
    14.         dic[$word]=1
    15.     fi
    16. done
    17.  
    18. for key in `echo ${!dic[*]}`
    19. do
    20.     echo "$key ${dic[$key]}"
    21. done
    22.  
    23. exit 0
    24.  
    25.

    利用文件处理顺序

    1. #!/bin/bash
    2.  
    3. declare -A dic
    4.  
    5. for word in `cat nowcoder.txt`
    6. do
    7. 	if [ $word = "" ];then
    8. 		continue
    9. 	fi
    10. 	if [ -v dic[$word] ]; then
    11. 		r=${dic[$word]}
    12. 		dic[$word]=`expr $r + 1`
    13. 	else
    14. 		dic[$word]=1
    15. 	fi
    16. done
    17.  
    18. rm tmp.txt
    19. touch tmp.txt
    20.  
    21. for key in `echo ${!dic[*]}`
    22. do
    23. 	echo "${dic[$key]} $key" >> tmp.txt
    24. done
    25.  
    26. cat tmp.txt | sort -n |awk  '{print $2,$1}'
    27. exit 0

    知识点：

    1、字典声明用declare -A dic

    2、字典赋值dic[key]=value

    3、获取所有key , ${!dic[*]}

    4、获取所有value, ${dic[*]}

    linux 程序设计 第四版 shell 脚本

    已调试，大致没问题，想学习的复制拿去

    1. #!/bin/sh
    2.  
    3. menu_choice=""
    4. current_cd=""
    5. title_file="title.cdb"
    6. tracks_file="tracks.cdb"
    7. temp_file=/tmp/cdb.$$
    8. trap 'rm -f $temp_file' EXIT
    9.  
    10. get_return() {
    11. 	echo "Please return \c"
    12. 	read x
    13. 	return 0
    14. }
    15.  
    16. get_confirm() {
    17. 	echo -e "Are you sure? \c"
    18. 	while true
    19. 	do
    20. 		read x
    21. 		case "$x" in
    22. 			y | yes|Y|Yes|YES) return 0;;
    23. 			n | no|N|No|NO) 
    24. 				echo
    25. 				echo "Cancelled"
    26. 				return 1;;
    27. 			*) echo "Please enter yes or no";;
    28. 		esac
    29. 	done
    30.  
    31. }
    32.  
    33. set_menu_choice() {
    34. 	clear
    35. 	echo "Options : -"
    36. 	echo
    37. 	echo "   a) Add new CD"
    38. 	echo "   f) Find CD"
    39. 	echo "   c) Cont the CDs and tracks in the catalog"
    40. 	if [ "$cdcatnum" != "" ]; then
    41. 		echo "   l) List track on $cdtitle"
    42. 		echo "   r) Remove $cdtitle"
    43. 		echo "   u) Update track information for $cdtitle"
    44. 	fi
    45. 	echo "   q) Quit"
    46. 	echo 
    47. 	echo  "Please enter choice then press return \c"
    48. 	read menu_choice
    49. 	return
    50. }
    51.  
    52. insert_title() {
    53. 	echo $* >> $title_file
    54. 	return
    55. }
    56.  
    57. insert_track() {
    58. 	echo $* >> $tracks_file
    59. 	return
    60. }
    61.  
    62. add_record_tracks() {
    63. 	echo "Enter track information for this CD"
    64. 	echo "When no more tracks enter q"
    65. 	cdtrack=1
    66. 	cdtitle=""
    67. 	while [ "$cdtitle" != "q" ] 
    68. 	do
    69. 		echo "Track $cdtrack, track title? \c"
    70. 		read tmp
    71. 		cdtitle=${tmp%%, *}
    72. 		echo ${tmp}======
    73. 		echo ${cdtitle}-------
    74. 		if [ "$tmp" != "$cdtitle" ]; then
    75. 			echo "Sorry, no commas allowed"
    76. 			continue
    77. 		fi
    78.  
    79. 		if [ -n "$cdtitle" ]; then
    80. 			echo enter
    81. 			echo ${cdtitle}-------
    82. 			if [ "${cdtitle}" != "q" ]; then
    83. 				echo enter1
    84. 				insert_track $cdcatnum, $cdtrack, $cdtitle
    85. 			fi
    86. 		else
    87. 			cdtrack=$((cdtrack-1))
    88. 		fi
    89. 	  cdtrack=$((cdtrack+1))
    90. 	done
    91. }
    92.  
    93. add_records() {
    94. 	echo "Enter catalog name \c"
    95. 	read tmp;
    96. 	cdcatnum=${tmp%%, *}
    97. 	echo "Enter title \c"
    98. 	read tmp
    99. 	cdtitle=${tmp%%, *}
    100. 	
    101. 	echo "Enter type \c"
    102. 	read tmp
    103. 	cdtype=${tmp%%, *}
    104. 	
    105. 	echo "Enter artist/composer \c"
    106. 	read tmp
    107. 	cdac=${tmp%%, *}
    108.  
    109. 	echo About to add new entry
    110. 	echo "$cdcatnum $cdtitle $cdtype $cdac"
    111. 	
    112. 	if get_confirm; then
    113. 		insert_title $cdcatnum, $cdtitle, $cdtype, $cdac
    114. 		add_record_tracks
    115. 	else
    116. 		remove_records
    117. 	fi
    118. 	return
    119. }
    120.  
    121. find_cd() {
    122. 	if [ "$1" = "n" ] ; then 
    123. 		asklist=n
    124. 	else
    125. 		asklist=y
    126. 	fi
    127. 	cdcatnu=""
    128. 	echo -e "Enter a string to search for in the CD titles \c"
    129. 	read searchstr
    130.  
    131. 	if [ "$searchstr" = "" ] ; then
    132. 		return 0
    133. 	fi
    134. 	
    135. 	grep "$searchstr" $title_file > $temp_file
    136. 	
    137. 	set $(wc -l $temp_file)
    138. 	linesfound=$1
    139. 	
    140. 	case "$linesfound" in
    141.  
    142. 	0)   echo "Sorry, nothing found"
    143. 		get_return
    144. 		return 0;;
    145. 	1)  ;;
    146. 	2)  echo "Sorry, not unique"
    147. 		echo "Found the following"
    148. 		cat $temp_file
    149. 		get_return
    150. 		return 0
    151. 	esac
    152.  
    153. 	IFS=","
    154. 	read cdcatnum cdtitle cdtype cdac < $temp_file
    155. 	IFS=" "
    156.  
    157. 	if [ -z "$cdcatnum" ]; then
    158. 		echo "Sorry, cound not extract catalog field from $temp_file"
    159. 		get_return
    160. 		return 0
    161. 	fi
    162. 	
    163. 	echo
    164.  
    165. 	echo Catalog num: $cdcatnum
    166. 	echo Title: $cdtitle
    167. 	echo TYPe: $cdtype
    168. 	echo Artist: $cdac
    169. 	echo
    170. 	get_return
    171. 	if [ "$asklist" = "y" ]; then
    172. 		echo -e "View tracks for this CD? \c"
    173. 		if [ "$x" = "y" ]; then
    174. 			echo
    175. 			list_tracks
    176. 			echo
    177. 		fi	
    178. 	fi
    179. 	return 1
    180. }
    181.  
    182.  
    183. update_cd() {
    184.  
    185. 	if [ -z "$cdcatnum" ]; then
    186. 		echo "You must select a CD first"
    187. 		find_cd n
    188. 	fi
    189.  
    190. 	if [ -n "$cdcatnum" ]; then 
    191. 		echo "Current tracks are: -"
    192. 		list_tracks
    193. 		echo
    194. 		echo "This will re_enter the tracks for $cdtitle"
    195. 		get_confirm && {
    196. 			grep -v "^${cdcatnum}," $tracks_file > $temp_file
    197. 			mv $temp_file $tracks_file
    198. 			echo
    199. 			add_record_tracks
    200. 		}
    201. 	fi
    202. 	return
    203. }
    204.  
    205. count_cds() {
    206. 	set $(wc -l $title_file)
    207. 	num_titles=$1
    208. 	set $(wc -l $tracks_file)
    209. 	num_tracks=$1
    210. 	echo found $num_title CDs, with a total of $num_tracks tracks
    211. 	get_return
    212. 	return
    213. }
    214.  
    215. remove_records() {
    216. 	if [ -z "$cdcatnum" ]; then
    217. 		echo You must select a CD first
    218. 		find_cd n
    219. 	fi
    220.  
    221. 	if [ -n "$cdcatnum" ]; then
    222. 		echo "You are about to delete $cdtitle"
    223. 		get_confirm && {
    224. 			grep -v "^${cdcatnum}," $title_file > $temp_file
    225. 			mv $temp_file $title_file
    226. 			grep -v "^${cdcatnum}," $tracks_file > $temp_file
    227. 			mv $temp_file $tracks_file
    228. 			cdcatnum=""
    229. 			echo Entry removed
    230. 		}
    231. 		get_return
    232. 	fi
    233.  
    234. 	return
    235. }
    236.  
    237.  
    238. list_tracks() {
    239. 	if [ "$cdcatnum" = "" ]; then
    240. 		echo no CD selected yet
    241. 		return
    242. 	else
    243. 		grep "^${cdcatnum}," $tracks_file > $temp_file
    244. 		num_tracks=$(wc -l $temp_file)
    245. 		if [ "$num_tracks" = "0" ]; then
    246. 			echo no tracks found for $cdtitle
    247. 		else {
    248. 			echo
    249. 			echo "$cdtitle :-"
    250. 			echo 
    251. 			cut -f 2- -d, $temp_file
    252. 		} | ${PAGER:-more}
    253. 		fi
    254. 	fi
    255. 	get_return
    256. 	return
    257. }
    258.  
    259. rm -f $temp_file
    260.  
    261. if [ ! -f $title_file ];then
    262. 	touch $title_file
    263. fi
    264.  
    265. if [ ! -f $title_file ]; then
    266. 	touch $tracks_file
    267. fi
    268.  
    269. clear
    270. echo
    271. echo
    272. echo "Mini CD manager"
    273. sleep 1
    274.  
    275. quit=n
    276. while [ "$quit" != "y" ];
    277. do
    278. 	set_menu_choice
    279. 	case "$menu_choice" in
    280. 		a)  add_records;;
    281. 		r)  remove_records;;
    282. 		f)  find_cd y;;
    283. 		u)  update_cd;;
    284. 		c)  count_cds;;
    285. 		l)  list_tracks;;
    286. 		b)  
    287. 			echo
    288. 			more $title_file
    289. 			echo
    290. 			get_return
    291. 			;;	
    292. 		q|Q) quit=y;;
    293. 		*) echo "Sorry, choice not recognized";;
    294. 	esac
    295. done
    296.  
    297. rm -f $temp_file
    298. echo "Finished"
    299. exit 0
    300.

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  • 原文地址：https://blog.csdn.net/TSC1235/article/details/133847735