#!/bin/bash -
#echo do you have exetuate this project \n
printf "please input your passwd"
stty -echo
read pass < /dev/tty
printf "please agein input your passwd"
read pass2 < /dev/tty
stty echo
#tr -s > 1.txt | sort > 2.txt
#echo "1 6 8 1 4 9" > 1.txt | sort 1.txt | tail 1.txt
#cat /dev/null
#!/bin/bash
#cat /bin/liupeng | grep a | wc
#$1
#read $x
#echo $x
#set -x #跟踪
#echo firset echo
#set +x #取消跟踪
#echo second echo
#locale -a | grep "^L" #环境变量
#LC_ALL=da locale ck LC_TIME
######------------------------------grep+正则表达式-----------------------------#
#who | grep -F u1 #判断登录用户
#cat 1.txt | grep ^a | grep b$
#cat 1.txt | grep Aa.Aa #[Aa]d #含有Aa的字符
#cat 1.txt | grep ^Aa #以Aa开头的字符
#cat 1.txt | grep Aa$ #以Aa结尾的字符
#cat 1.txt | grep [[:digit:]] | grep ^2 #匹配含有数字的行列
#cat 1.txt | grep [[:alnum:]]
#cat 1.txt | grep \digit
#cat 1.txt | grep ab*c #匹配含有一个a额字符
#cat 1.txt | grep [[:upper:]]\{3\}$ #匹配后三位为大写的字符
#cat 1.txt | grep ab?c #匹配ab和abc
#cat 1.txt | grep ab+c
#----------------------------------sed+正则表达式_______________________________
#sed ‘s/:.*//‘ /root/1.txt
#find /root -type d -print
#mkdir -p /home/1
#sed ‘s;/home/1;/home/2;‘
# cat /root/1.txt | sed ‘s/a/B/g‘ #替换字符
#n
#printf "hello world"
#sed -n ‘/c/p‘ *.txt
#sed -n ‘$p‘ "$1"
#sed -n ‘2,5p‘ /root/1.txt #匹配打印的行数
echo "hello world" | sed ‘s/world/shell/‘ #替换指定的字符【shell脚本学习-2】
原文：https://www.cnblogs.com/activecode/p/9526393.html
