shell-条件判断
菜单 case select从/etc/init.d/httpd里拷的一段
case "$1" in
start)
start
;;
stop)
stop
;;
status)
status -p ${pidfile} $httpd
RETVAL=$?
;;
restart)
stop
start
;;
*)
echo $"Usage: $prog {start|stop|restart|condrestart|reload|status|fullstatus|graceful|help|configtest}"
exit 1
esac
case"chioce" in
"var1" )
command
;;
"var2" )
command
;;
"var3" )
command
;;
* )
command
exit 1
esac
例一：输入一个键，判断是大写字母还是小写字母，还是数字，还是其它
while true
do
read -n 1 -p "请输入一个键值:" key
echo
case "$key" in
[[:upper:]] )
echo "你输入的是一个大写字母"
;;
[[:lower:]] )
echo "你输入的是一个小写字母"
;;
[[:digit:]] )
echo "你输入的是一个数字"
;;
[[:punct:]] )
echo "你输入的是一个标点符号"
;;
* )
echo "你输入的是其它"
;;
esac
done
使用read让用户输入它的名字，性别（对性别进行判断），年龄（判断是否有18岁成年)
#!/bin/bash
read -p "请输入你的姓名:" name
read -n 1 -p "请输入你的性别(M和W或m和w):" sex
echo
read -p "请输入你的年龄:" age
[ $age -ge 18 ] && a=1 || a=0
case "$sex" in
M | m)
case "$a" in
1 ) echo "$name先生" ;;
0 ) echo "$name小子" ;;
esac
;;
W | w)
case "$a" in
1 ) echo "$name女士" ;;
0 ) echo "$name小姐" ;;
esac
;;
* )
echo "性别有误,请重新运行"
exit 1
;;
esac
交互输入一个人名，选择性别，或者姓名，显示相应的人的资料
#!/bin/bash
echo -e"your sex?\nale\nemale"
read sex
case "$sex" in
M|m )
echo "先生好!"
;;
F|f )
echo "女士好!"
;;
* )
echo "选择错误!请重选"
sh $0
esac
=========================================================
echo "=================================="
echo " choose your sex "
echo " 1-male "
echo " 2-female "
echo " 0-exit "
echo "=================================="
echo -e "please enter your choice(0-2):\c "
read choice
case "$choice" in
1 )
clear
echo "you are male"
;;
2 )
clear
echo "you are female"
;;
0 )
exit 1
clear
;;
* )
echo "invalid choice! please choose (0-2);"
clear
esac
改写上一个题目，在case里面再嵌套case菜单，使之选项更丰富
while true
do
echo "=================================="
echo " choose your sex "
echo " 1-male "
echo " 2-female "
echo " 0-exit "
echo "=================================="
echo -e "please enter your choice(0-2):\c "
read choice
case "$choice" in
1 )
clear
echo "you are male"
read -n 1 -p "are you a gay? y/n :" answer1
case "$answer1" in
Y|y) echo && echo 'oh,gosh';;
N|n) echo &&echo 'congratulations!';;
*)echo &&echo 'what is your problem';;
esac
;;
2 )
clear
echo "you are female"
read -n 1 -p "are you a lesbian? y/n :" answer2
case "$answer2" in
Y|y) echo && echo 'what a pity!';;
N|n) echo && echo 'Can i have your number';;
*)echo && echo 'what is your problem';;
esac
;;
0 )
exit 1
clear
;;
* )
echo "invalid choice! please choose (0-2);"
clear
esac
done
------------------------------------------------------------------
select建立菜单选项的另一种工具，它是从ksh引进的
PS3＝""
select var inchoice1 choice2 choice3 ...
do
echo "................."
done
例五：用select做一个选择菜单
PS3="please choose what operation system you are using:" --PS3是select命令用来加入提示字符串的符号，（默认会使用#?)
echo
select os inxp vista windows7 linux unix
do
echo
echo "your operation system is $os"
echo
break --这里不加break的话，就会一直循环让你选择
done
=========================================================
函数
function_name () {
command
command
}
function function_name () {
command
command
}
模拟用函数写一个服务启动，关闭，重启的脚本 （要求有start,stop,restart,status,支持chkconfig等功能) --提示:使用随机数来做pid文件
vim 5.sh
#!/bin/bash
# chkconfig: - 85 15
# description: This is a test program.
start () {
[ -e /var/run/testd.pid ] && echo "already startd" && exit 1
echo -n "starting testd:"
for i in `seq 5`
do
echo -n "."
sleep 1
done
echo -n " "
echo
echo $RANDOM > /var/run/testd.pid
}
stop () {
echo -n "stopping testd:"
for i in `seq 5`
do
echo -n "."
sleep 1
done
echo -n " "
echo
[ -e /var/run/testd.pid ] && rm -rf /var/run/testd.pid
}
status () {
[ -e /var/run/testd.pid ] && echo "testd (pid `cat /var/run/testd.pid`) is running..." || echo "testd is stopped"
}
case "$1" in
start )
start ;;
stop )
stop ;;
restart )
stop
start ;;
status )
status ;;
* )
echo "USAGE:start|stop|restart|status"
exit 1
esac
cp 5.sh /etc/init.d/testd
chmod 755 /etc/init.d/testd
chkconfig --add testd
chkconfig testd on --level 2345
read输入一个目录，找出目录下包括子目录下为死链接的文件。（要求不使用find，使用函数进行递归查找子目录里的文件)
#!/bin/bash
ckdeadlink () {
for i in $1/*
do
[ -h $i -a ! -e $i ] && echo "$i为死链接"
[ -d $i ] && ckdeadlink $i
done
}
read -p "输入一个目录:" dir
echo
ckdeadlink $dir
结合函数和case菜单功能，写一下关于usb挂载的脚本，（要实现的功能有挂载，卸载，列出挂载后内容，usb拷贝文件到系统，系统拷贝文件到usb，退出等六个功能）
#!/bin/bash
mountusb () {
clear
fdisk -l |grep sd
echo -n "请选择你的挂载的设备(写全名，如/dev/sdb1): "
read dev
mount $dev /mnt
}
umountusb () {
clear
cd /
umount /mnt
echo "卸载完成"
}
display () {
clear
ls -l /mnt
}
usbtosystem () {
clear
echo -n "选择你要拷的文件(写相对路径): "
read file1
echo -n "选择你要拷到哪个路径(写绝对路径): "
read path1
cd /mnt
cp $file1 $path1/
}
systemtousb () {
clear
echo -n "选择你要拷的系统文件(写绝对路径): "
read file2
echo -n "选择你要拷到usb哪个路径(写绝对路径): "
read path2
cp $file2 $path2/
}
quit () {
clear
echo "##############"
echo " 谢谢使用@_@ "
echo "##############"
exit 1
}
while true
do
echo "##################################"
echo " usb mount program by li "
echo "##################################"
echo " "
echo " 1-挂载 "
echo " 2-卸载 "
echo " 3-列出内容 "
echo " 4-拷文件到系统 "
echo " 5-拷文件到usb "
echo " 0-退出程序 "
echo " "
echo "##################################"
echo -n "请选择(0-5): "
read choice
case "$choice" in
1 ) mountusb ;;
2 ) umountusb ;;
3 ) display ;;
4 ) usbtosystem ;;
5 ) systemtousb ;;
0 ) quit ;;
* ) echo "只能选择0-5,请重新选择!";;
esac
done
=============================================
正则表达式
. 一个字符
.. 两个字符
^# 以#号开头
#$ 以#号结束
包含a或b或c的都匹配
[^abc] 只要出现了abc这三个字母以外的字符就都匹配 --重点
a+ 匹配至少一个或多个a
a* 匹配0或多个a
a? 匹配0或1个a
大写 [[:upper:]]
小写 [[:lower:]]
字母 [[:alpha:]]
字母数字 [[:alnum:]]
空格或者制表符 [[:blank:]]
纯数字 [[:digit:]]
标点符号 [[:punct:]]
========================================================
显示查出的行在原文件的行号加n参数 grep -n root /etc/passwd
反向查找加v参数grep -v bin /etc/passwd
大小写不敏感加i参数grep -ni root grep.txt
查找出有rot或者是rat的行 grep -n rt grep.txt --注意的是，［ ］括号内不论几个字符，都是选一个
查找一个非r字符加oot连在一起的行 grep'[^r]oot' grep.txt
查找不以小写字母开头grep'[^a-z]oo' grep.txt
--记住： [] 里的^为取反 ，外面的为以它开头
# grep'^oot' grep.txt
root
boot
# grep'[^a-z]oot' grep.txt --表示有一个非小写字符连着oot的就会被找出来
Root
Boot
# cat test
root
Root
rot
boot
Rot
# grep '[^A-Z]o' test --查找不以大写字母的一个字符连着一个o
root
Root
rot
boot
# grep '[^A-Z]oo' test--查找不以大写字母的一个字符连着两个o
root
boot
# grep '^[^A-Z]' test --这等同于不以大写字母开头（但可以以小写，数字，或空格等开头)
root
rot
boot
查找不以大写字母开头 grep '[^[:upper:]]' grep.txt
grep'^[^A-Z]' grep.txt
查找有数字的号 grep '' grep.txt
或者 grep [[:digit:]] grep.txt
查找一个数字和一个字母连起来的行
grep '' grep.txt
行首^ 行尾$
查找不以r开头的 grep -v ^r grep.txt
查找以数字开头的 grep ^grep.txt
grep ^[[:digit:]] grep.txt
查找以大写字母开头的 grep ^ grep.txt 或者 grep ^[[:upper:]] grep.txt
查找以小写字母开头的 grep ^ grep.txt 或者 grep ^[[:lower:]] grep.txt
查找以点结束的 grep "\."$ grep.txt--注意要引起来，而且要转义
去掉空格行 catgrep.txt|grep -v ^$ --以^$表示空格行
查找完全匹配abc的grep^abc$ grep.txt
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
.点号代表一个任意字符
*代表零个或者多个前字符
.*代表0个或多个任意字符
# cat grep.txt
ggle
gogle
gooogle
gagle
gaagle
gaaagle
abcgef
abcdef
比较：
grep 'g.g' grep.txt--只要两个g字母中间有一个任意字符就可以
grep 'g*g' grep.txt --只要有一个g字母就可以。等同于grep g grep.txt
grep 'go*g' grep.txt --只要两个g字母中间有零个o或多个o就可以
grep 'g.*g' grep.txt --只要两个g字母中间有零个或任意个字符就可以
grep 'go.*g' grep.txt--只要go与g字母中间有零个或任意个字符就可以
==================================================================
expect 自动应答TCL语言
yum install expect -y
Summary : A program-script interaction and testing utility
Description :
Expect is a tcl application for automating and testing
interactive applications such as telnet, ftp, passwd, fsck,
rlogin, tip, etc. Expect makes it easy for a script to
control another program and interact with it.
This package contains expect and some scripts that use it.
例一：使用自动应答修改用户密码
#!/bin/bash
expect &1
spawn passwd $1--产生passwd $1这个命令
expect "rd:"--当停在rd:结尾这个标识符时
send "456\r"--我就把456传给它
expect "rd:"--当再次停在rd:结尾这个标识符时
send "456\r"--我就再次把456传给它
expect eof--表示expect结束
EOF
# sh 8.sh user2 --执行方法，因为脚本里写的是$1，所以后面接你要修改密码的用户名
－－－－－－－－－－－－－－－－－－－－－
#!/bin/bash
sed -i "/^2.2.2.95/d" /root/.ssh/known_hosts
expect/dev/null 2>&1
spawn ssh 2.2.2.95
expect "no)?"
send "yes\r"
expect "password:"
send "123456\r"
expect "]#"
send "mkdir /root/Desktop/test\n"
send "touch /root/Desktop/test/{1..10}\n"
send "exit\n"
expect eof
EOF
# sh 9.sh--执行方法
-----------------------------
#!/usr/bin/expect
set host
set user
set passwd
spawn ssh $user@$host
expect "password:"
send "$passwd\r"
expect "]#"
send "touch /root/Desktop/abc\n"
send "exit\n"
# sh 10.sh 2.2.2.95 root 123456 --这样执行是错误的。因为sh命令就是直接调用bash去解释，不管你脚本开头定义的#!/usr/bin/expect
# chmod 755 10.sh
# ./10.sh 2.2.2.95 root 123456 --正确执行方法
====================================================
题目：
用read输入一个文件，然后把行数倒序输出（上下倒序)，保存到一个新文件
#!/bin/bash
read -p "input a filename:" file
[ -e /tmp/reserve.txt ] && rm -rf /tmp/reserve.txt
line=`cat $file | wc -l`
for (( i=$line;i>0;i-- ))
do
echo `head -$i $file | tail -1` >> /tmp/reserve.txt
done
使用read输入一个整数，把数字中的所有数字转换成英文单词
如:2345转换为 two three four five
提示：需要计算输入的整数的长度，然后进行循环，截取整数中的单一字符(man cut)，对截取的单一字符使用case菜单分类，最后打印
#!/bin/bash
read -p "输入一个整数:" num
length=`echo $num |wc -c`
length=$[$length-1]
for (( i=1;i"
send "mirror shell /root\n"
send "quit\n"
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