貓寧~~~
建議全程在centos7中進行，我在kali linux中有些命令無法執行。
1~家目錄下建立bin檔案，test.sh檔案在bin目錄
下面的shell程式碼列印Hello World!
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "Hello China! \a \n" exit 0
2~輸入名稱，變數前空格一定要嚴格空出來哦
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH read -p "Please input your first name:" firstname read -p "Please input your last name:" lastname echo -e "\nYour full name is:${firstname} ${lastname}"
sh test.sh
echo ${firstname} ${lastname}，空
source test.sh
echo ${firstname} ${lastname}，不空
3~批量建立檔案，自定義名稱之後新增時間，設定大量變數
不定義檔名字首，預設是filename，直接回車即可
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "I will use 'touch' command to create 3 files." read -p "Please input your filename:" fileuser filename=${fileuser:-"filename"} date1=$(date --date="2 days ago" +%Y%m%d) date2=$(date --date="1 days ago" +%Y%m%d) date3=$(date +%Y%m%d) file1=${filename}${date1} file2=${filename}${date2} file3=${filename}${date3} touch "${file1}" touch "${file2}" touch "${file3}"
4~兩個數相乘運算
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "You should input 2 numbers,I will multiplying them! \n" read -p "first number:" firstnu read -p "second number:" secnu total=$((${firstnu}*${secnu})) echo "\nThe result of ${firstnu}*${secnu} is ==> ${total}"
echo $((120*120)) 乘積，整數計算
echo $((13%3)) 取餘
echo "1.2*1.2" | bc 小數計算，新增bc，bc在centos7上可以用，但是在kali linux上不可以
5~計算π的值，4*a(1)是bc提供的計算π的函式
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "This program will calculate pi value. \n" echo -e "You should input a float number to calculate pi value. \n" read -p "The scale number (10~10000):" checking num=${checking:-"10"} echo "Starting calcuate pi value. Be patient." time echo "scale=${num}; 4*a(1)" | bc -lq
6~test判斷
目錄是否存在
在/root下建立test目錄
test -e /test && echo "exist" || echo "Not exist"
列印exist
test -e /root/test && echo "exist" || echo "Not exist"
列印Not exist
-e 檔案或目錄
-f 針對檔案存在與否
-d 針對目錄存在與否
檔案許可權相關
test -s /root/test.html && echo "exist" || echo "Not exist"
-r 可讀
-w 可寫
-x 可執行
-s 檔案是否為空
檔案比較
test1.html更新，列印exist
test test1.html -nt test.html && echo "exist" || echo "Not exist"
-nt 更新
-ot 更舊
-ef 是否為同一個檔案
整數間判定
test 1 -eq 1 && echo "exist" || echo "Not exist" 列印exist
-eq 相等
-ne 不等
-gt 前者大於後者
-lt 前者小於後者
-ge 前者大於等於後者
-le 前者小於等於後者
字串判定
test -z 111 && echo "exist" || echo "Not exist" 列印Not exist
-z 字串為空顯示exist，其他顯示Not exist
-n 字串為空顯示Not exist，其他顯示exist
test 111 == 111 && echo "exist" || echo "Not exist"
111 == 111 相等，列印exist，不相等，列印Not exist
111 != 111 相等，列印Not exist，不相等，列印exsit
多重條件判定
-rw-r--r--. 1 root root 5556 Oct 11 20:49 test.html
test -r test.html -a -x test.html && echo "exist" || echo "Not exist" 列印Not exist
test ! -x test.html && echo "exist" || echo "Not exist" 沒有執行許可權，列印exist
-a and關係
-o or關係
! 相反
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "Please input a filename,I wiil check the filename's type and permission. \n\n" read -p "Input a filename:" filename test -z ${filename} && echo "You must input a filename." && exit 0 test ! -e ${filename} && echo "The filename '${filename}' DO NOT exist" && exit 0 test -f ${filename} && filetype="regulare file" test -d ${filename} && filetype="directory" test -r ${filename} && perm="readable" test -w ${filename} && perm="${perm} writable" test -x ${filename} && perm="${perm} executable" echo "The filename:${filename} is a ${filetype}" echo "And the permissions for you are:${perm}"
檔名為空顯示
You must input a filename.
目錄
Input a filename:test
The filename:test is a directory
And the permissions for you are:readable writable executable
檔案不存在
Input a filename:120
The filename '120' DO NOT exist
檔案存在
Input a filename:test.html
The filename:test.html is a regulare file
And the permissions for you are:readable writable
7~判斷符號
[ "abcd" == "abcd" ] ; echo $? 列印0
[ "abcd" == "abc" ] ; echo $? 列印1
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH read -p "Please input (Y/N):" yn [ "${yn}" == "Y" -o "${yn}" == "y" ] && echo "OK,continue" && exit 0 [ "${yn}" == "N" -o "${yn}" == "n" ] && echo "Oh,interrupt" && exit 0 echo "I don't know what your choice is" && exit 0
8~預設變數
[root@pjzhang ~]# file /etc/init.d/network
/etc/init.d/network: Bourne-Again shell script, ASCII text executable
檔案是可執行指令碼
/etc/init.d/network stop，start，status
$0 指令碼檔名
$# 後接引數個數
$@ 引數全部內容，加雙引號
${1} 第一個引數
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo "The script name is ==>${0}" echo "Total parameter number is ==>$#" [ "$#" -lt 2 ] && echo "The number of parameter is less than 2. Stop here." && exit 0 echo "Your whole parameter is ==>'$@'" echo "The 1st parameter ==>${1}" echo "The 2st parameter ==>${2}"
第一次偏移掉1個，第二次在第一次基礎上偏移掉3個，從前向後
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo "Total parameter number is ==>$#" echo "Your whole parameter is ==>'$@'" shift echo "Total parameter number is ==>$#" echo "Your whole parameter is ==>'$@'" shift 3 echo "Total parameter number is ==>$#" echo "Your whole parameter is ==>'$@'"
over~~~