零碎知识点
- 开启一个脚本相当于开启一个子进程，变量不会继承
- 注意（）里面也会开启子进程，变量不会继承，如果想要作为一个整体要用{}。
- 但是注意exit的返回值即使在（）里面，但如果它是最后一个命令执行过后产生的，没有再赋予新值，则它在当前的shell中仍然可以继承判断。就如同之前的 echo $name;(echo $name;) ,只要小括号内没有赋值，则两个name显示的结果一样，小括号和直接输入bash开启子进程仍然略有不同。
.vimrc设置，它要放在 ~/内
~/.vimrc
set ignorecase
set cursorline
set autoindent
autocmd BufNewFile *.sh exec ":call SetTitle()"
func SetTitle()
if expand("%:e") == 'sh'
call setline(1,"#!/bin/bash")
call setline(2,"#")
call setline(3,"#********************************************************************")
call setline(4,"#Author: ZhangYinsheng")
call setline(5,"#QQ: 744004845")
call setline(6,"#Date: ".strftime("%Y-%m-%d"))
call setline(7,"#FileName： ".expand("%"))
call setline(8,"#URL: https://blog.51cto.com/14228129.")
call setline(9,"#Description： The test script")
call setline(10,"#Copyright (C): ".strftime("%Y")." All rights reserved")
call setline(11,"#********************************************************************")
call setline(12,"")
endif
endfunc
autocmd BufNewFile * normal G判断centos版本
IDCentos_release_version.sh
#!/bin/bash
case "`cat /etc/redhat-release |grep -Eo " [0-9]{1,2}"|tr -d " " `" in
4)
echo "Centos version is 4" ;;
5)
echo "Centos version is 5" ;;
6)
echo "Centos version is 6" ;;
7)
echo "Centos version is 7" ;;
8)
echo "Centos version is 8" ;;
9)
echo "Centos version is 9" ;;
10)
echo "Centos version is 10" ;;
esac
- 去掉数字前方一个或者多个空格有一个简单的方法，就是让一个变量等于它，然后输出的时候不加上引号，就可以了，空格也算在格式里面了。
- 比如把上面的case后面的长式子赋值给一个变量之后再判断，就不需要用tr命令去除空格了。
- 但如果是字符中间的多个空格用这种方法会变成一个，不会全部去掉要注意。
报警磁盘和inode编号用量：
#!/bin/bash
Perscent=10 #警告阈值
Usedisk="`df | grep "/dev/sd"|grep -E " [0-9]+%" -o| tr -d "%" |sort -nr |head -1 `";
InodeUsedisk="`df -i | grep "/dev/sd"|grep -E " [0-9]+%" -o| tr -d "%" |sort -nr |head -1 `";
[ $Usedisk -ge $Perscent ] && echo Warning! Useddisk is ${Usedisk}% ;
[ $InodeUsedisk -ge $Perscent ] && echo Warning! InodeUseddisk is ${InodeUsedisk}% ;
[ $Usedisk -lt $Perscent ] && [ $InodeUsedisk -lt $Perscent ] && echo Disk Using Condition is Good!;
脚本参数引用以及$*,$@,shift判断
agr1.sh agr1 arg2...
#!/bin/bash
echo "1st arg is $1"
echo "2st arg is $2"
echo "2st arg is $3"
echo "10st arg is ${10}"
echo "all args are $*"
echo "all args are $@"
echo "args sumnumber is $#"
echo "scriptname is `basename $0`"
echo -e "\e[1;33marg2 use \$* begins test:\e[0m"
arg2.sh "$*" #use $*
echo -e "\e[1;33marg3 use \$@ begins test:\e[0m"
arg3.sh "$@" #use $@
echo -e "\e[1;32mShift once test:\e[0m"
shift
echo "1st arg is $1"
echo "2st arg is $2"
echo "2st arg is $3"
echo "10st arg is ${10}"
echo -e "\e[1;32mShift twice test:\e[0m"
shift
echo "1st arg is $1"
echo "2st arg is $2"
echo "2st arg is $3"
echo "10st arg is ${10}" arg2.sh同arg3.sh:
#!/bin/bash
echo "1st arg is $1"
echo "2st arg is $2"
echo "2st arg is $3"
echo "10st arg is ${10}"
echo "all args are "$*""
echo "all args are "$@""
echo "args sumnumber is $#"
echo "scriptname is `basename $0`"测试环境变量脚本中传递
father.sh
#!/bin/bash
export name=farther
echo "start farther.sh"
echo "name=$name"
echo "farther pid is $BASHPID"
son.shson.sh
#!/bin/bash
echo "starting son.sh "
echo "son.sh pid is $BASHPID"
echo "name=$name"
sleep 100网络拷贝文件到另一台主机（简单版本）
scpfile.sh arg1 arg2....
#!/bin/bash
scp $* [email protected]:/data/scripttest查看主机的各种信息，包括主机名，IPv4地址，操作系统版本，内核版本， CPU型号，内存⼤⼩，硬盘⼤⼩
SysteminfoCheck.sh
#!/bin/bash
备份文件（手动版本）
backup.sh
#! /bin/bash
#SOURCE="/data/script36"
DEST="/data/backup/backupfile_`date "+%F_%T"`" #Destination cp directory
BEGINCOLOR="\e[1;35m"
ENDCOLOR="\e[0m"
NOPASS=0 #Used to determine whether All filename are correct and exist, 0 is yes ,1is no.
#ARGNUM=$#
set -u
#variable is not exist ,then exit
#set -e
if [ $# -eq 0 ]; then
echo -e "\e[1;31mPlease input one or more filename[directory]correctly!!!\e[0m"
echo -e "\e[1;31mFor example :\e[0m\n\e[1;32mbackup.sh\e[0m /home/zhang/ /dev/zero ..."
exit
else
echo -e "\e[1;36mCheck input filename whether exists or not...\e[0m"
for n in $*;do
if [[ ! -a "$n" ]];then
echo -e "\e[1;31mThere is no file[Dir]\e[0m\e[1;5;41m$n\e[0m";
NOPASS=1;
#Judge if file exist;
fi
done
#exit;
if [ $NOPASS -eq 1 ] ;then
echo -e "\e[1;5;31mCheck Not Pass ,Please check your input filename and redo!!!\e[0m"
exit
fi
echo -e "\e[1;32mFilename check done,All file exists\e[0m"
fi
#sleep 50
echo -e "\e[1;33mGet Ready For Backup After 10 Seconds...\e[0m"
sleep 0.5
echo -e "\e[1;5;31mYou can press down key \e[0m\e[1;5;34m\"ctrl + c\"\e[0m\e[1;5;31m to stop backup now!\e[0m"
sleep 0.5
echo "Counting down:"
for i in {1000..1};do #10seconds to stop backup
x=$[i/100];
y=$[i%100];
if [ $y -lt 10 ]; then
y="0$y"
fi
let Rdmcolor=$RANDOM%7+31
echo -ne "\e[1;${Rdmcolor}m\e[K${x}.${y}\e[0m\r";
sleep 0.01
done
if [[ ! -d "$DEST" ]]; then
mkdir -p "$DEST";
echo -e "\e[1;32mMaking Backup_Destination_Directory Successfully!!!\e[0m";
fi
#sleep 0.1
echo -e "${BEGINCOLOR}Starting backup....$ENDCOLOR"
#sleep 0.1
cp -a -v -u --backup=numbered $* $DEST
echo -e "${BEGINCOLOR}Backup is finished~$ENDCOLOR"
echo -e "\e[1;32mFile backup to Directory '$DEST'\e[0m"
# unset SOURCE DEST BEGINCOLOR ENDCOLOR
每日定时备份文件（自动版本）
- 可以用软链接指向backup.sh并判断来进行设置，也可重新在写一个脚本
查看当前远程连接到此电脑的主机数的IP地址和个数，并按照从大到小顺序排列。
linkcheck.sh
#!/bin/bash
echo "The Sumnumber and IPAdress Connecting Now:"
netstat -tan | tr -s " " ":" |cut -d: -f6 |grep -Eo "(([1-9][0-9]?|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([1-9][0-9]?|1[0-9]{2}|2[0-4][0-9]|25[0-5])"|sort|uniq -c
- 附加用法：可以这样写来加入路径
PATH=/###/###:$PATH
echo $PATH >> /etc/profile.d/evn.sh
新装linux环境设置（初版）
- 变量修改要包含PATH ，HISTCONTROL ,HISTFORMAT,HISTSIZE,PS1
- 要改别名
- 要改登陆提示信息issue,motd
- 要改umask控制新建文件的权限等
- 要配置~/.vimrc
#! /bin/bash