shell脚本编程示例

#!/usr/bin/expect
spawn scp /etc/fstab 192.168.8.100:/app
expect {
“yes/no” { send “yes\n”;exp_continue }
“password” { send “magedu\n” }
}
expect eof

#!/usr/bin/expect
spawn ssh 192.168.8.100
expect {
“yes/no” { send “yes\n”;exp_continue }
“password” { send “magedu\n” }
}
interact
#expect eof

变量

#!/usr/bin/expect
set ip 192.168.8.100
set user root
set password magedu
set timeout 10
spawn ssh $user@$ip
expect {
“yes/no” { send “yes\n”;exp_continue }
“password” { send “$password\n” }
}
interact

位置参数

#!/usr/bin/expect
set ip [lindex $argv 0]
set user [lindex $argv 1]
set password [lindex $argv 2]
spawn ssh $user@$ip
expect {
“yes/no” { send “yes\n”;exp_continue }
“password” { send “$password\n” }
}
interact
#./ssh3.exp 192.168.8.100 root magedu

执行多个命令

#!/usr/bin/expect
set ip [lindex $argv 0]
set user [lindex $argv 1]
set password [lindex $argv 2]
set timeout 10
spawn ssh $user@$ip
expect {
“yes/no” { send “yes\n”;exp_continue }
“password” { send “$password\n” }
}
expect “]#” { send “useradd haha\n” }
expect “]#” { send “echo magedu |passwd –stdin haha\n” }
send “exit\n”
expect eof
#./ssh4.exp 192.168.8.100 root magedu

shell脚本调用expect

#!/bin/bash
ip=$1
user=$2
password=$3
expect <<EOF
set timeout 10
spawn ssh $user@$ip
expect {
“yes/no” { send “yes\n”;exp_continue }
“password” { send “$password\n” }
}
expect “]#” { send “useradd hehe\n” }
expect “]#” { send “echo magedu |passwd –stdin hehe\n” }
expect “]#” { send “exit\n” }
expect eof
EOF
#./ssh5.sh 192.168.8.100 root magedu

创建函数文件

cat functions.main
#!/bin/bash
#functions.main
findit()
{
if [ $# -lt 1 ] ; then
echo “Usage:findit file”
return 1
fi
find / -name $1 –print
}

在脚本中定义及使用函数

示例：
cat func1
#!/bin/bash
# func1
hello()
{
echo “Hello there today’s date is `date +%F`”
}
echo “now going to the function hello”
hello
echo “back from the function”

trap示例
#!/bin/bash
trap ‘echo “signal:SIGINT”‘ int
trap -p
for((i=0;i<=10;i++))
do
 sleep 1
 echo $i
done
trap ” int
trap -p
for((i=11;i<=20;i++))
do
 sleep 1
 echo $i
done
trap ‘-‘ int
trap -p
for((i=21;i<=30;i++))
do
 sleep 1
 echo $i
done

select循环于菜单

select variable in list
do
循环体命令
done

创建无线循环

while true; do
循环体
done
until false; do
循环体
Done

示例：shift.sh
#!/bin/bash
#step through all the positional parameters
until [ -z “$1” ]
do
echo “$1”
shift
done
echo

示例：doit.sh
#!/bin/bash
# Name: doit.sh
# Purpose: shift through command line arguments
# Usage: doit.sh [args]
while [ $# -gt 0 ] # or (( $# > 0 ))
do
echo $*
shift
done

循环控制语句break
用于循环体中
break [N]：提前结束第N层循环，最内层为第1层
while CONDTIITON1; do
CMD1
…
if CONDITION2; then
break
fi
CMDn
…
done

循环控制语句continue
用于循环体中
continue [N]：提前结束第N层的本轮循环，而直接进入下一轮判断；最内层为第1层
while CONDTIITON1; do
CMD1
…
if CONDITION2; then
continue
fi
CMDn
…
done