猫宁~~~
建议全程在centos7中进行，我在kali linux中有些命令无法执行。
1~家目录下创建bin文件，test.sh文件在bin目录
下面的shell代码打印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 " exit 0
2~输入名称，变量前空格一定要严格空出来哦
#!/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 " Your full name is:${firstname} ${lastname}"
sh test.sh
echo ${firstname} ${lastname}，空
source test.sh
echo ${firstname} ${lastname}，不空
3~批量创建文件，自定义名称之后添加时间，设置大量变量
不定义文件名前缀，默认是filename，直接回车即可
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "I will use 'touch' command to create 3 files." read -p "Please input your filename:" fileuser filename=${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}"
4~两个数相乘运算
#!/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! " read -p "first number:" firstnu read -p "second number:" secnu total=$((${firstnu}*${secnu})) echo " The result of ${firstnu}*${secnu} is ==> ${total}"
echo $((120*120)) 乘积，整数计算
echo $((13%3)) 取余
echo "1.2*1.2" | bc 小数计算，添加bc，bc在centos7上可以用，但是在kali linux上不可以
5~计算π的值，4*a(1)是bc提供的计算π的函数
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo -e "This program will calculate pi value. " echo -e "You should input a float number to calculate pi value. " read -p "The scale number (10~10000):" checking num=${checking:-"10"} echo "Starting calcuate pi value. Be patient." time echo "scale=${num}; 4*a(1)" | bc -lq
6~test判断
目录是否存在
在/root下创建test目录
test -e /test && echo "exist" || echo "Not exist"
打印exist
test -e /root/test && echo "exist" || echo "Not exist"
打印Not exist
-e 文件或目录
-f 针对文件存在与否
-d 针对目录存在与否
文件权限相关
test -s /root/test.html && echo "exist" || echo "Not exist"
-r 可读
-w 可写
-x 可执行
-s 文件是否为空
文件比较
test1.html更新，打印exist
test test1.html -nt test.html && echo "exist" || echo "Not exist"
-nt 更新
-ot 更旧
-ef 是否为同一个文件
整数间判定
test 1 -eq 1 && echo "exist" || echo "Not exist" 打印exist
-eq 相等
-ne 不等
-gt 前者大于后者
-lt 前者小于后者
-ge 前者大于等于后者
-le 前者小于等于后者
字符串判定
test -z 111 && echo "exist" || echo "Not exist" 打印Not exist
-z 字符串为空显示exist，其他显示Not exist
-n 字符串为空显示Not exist，其他显示exist
test 111 == 111 && echo "exist" || echo "Not exist"
111 == 111 相等，打印exist，不相等，打印Not exist
111 != 111 相等，打印Not exist，不相等，打印exsit
多重条件判定
-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" 打印Not exist
test ! -x test.html && echo "exist" || echo "Not exist" 没有执行权限，打印exist
-a and关系
-o or关系
! 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. " 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}"
文件名为空显示
You must input a filename.
目录
Input a filename:test
The filename:test is a directory
And the permissions for you are:readable writable executable
文件不存在
Input a filename:120
The filename '120' DO NOT exist
文件存在
Input a filename:test.html
The filename:test.html is a regulare file
And the permissions for you are:readable writable
7~判断符号
[ "abcd" == "abcd" ] ; echo $? 打印0
[ "abcd" == "abc" ] ; echo $? 打印1
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH read -p "Please input (Y/N):" yn [ "${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~默认变量
[root@pjzhang ~]# file /etc/init.d/network
/etc/init.d/network: Bourne-Again shell script, ASCII text executable
文件是可执行脚本
/etc/init.d/network stop，start，status
$0 脚本文件名
$# 后接参数个数
$@ 参数全部内容，加双引号
${1} 第一个参数
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo "The script name is ==>${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 ==>${2}"
第一次偏移掉1个，第二次在第一次基础上偏移掉3个，从前向后
#!/bin/bash PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo "Total parameter number is ==>$#" 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~~~