10. Poweshell - 循环语句

• PowerShell 循环语句

1. 介绍

   for (初值;表达式;赋值语句) {代码}      用变量值控制执行次数

   foreach (成员变量 in数组) {代码}   利用迭代执行代码

   foreach-object                                                 对一组输入的每个对象执行运算

   while(表达式) {代码}                            表达式为真时循环执行代码

   do {代码} while(表达式)                       类似于while，            只是先执行代码，再判断表达式真假

   do {代码} until(表达式) 执行代码，     直至表达式为假

 2. 实际应用

例一：使用foreach 查询硬件信息（disk）

$DiskDrive=get-wmiobject-class Win32_DiskDrive -namespace root\CIMV2

foreach($item in $DiskDrive)

{

write-host"Description:" $item.Description

write-host"Device ID:" $item.DeviceID

write-host"Interface Type:" $item.InterfaceType

write-host"Media Type:" $item.MediaType

write-host"Model:" $item.Model

write-host"Partitions:" $item.Partitions

write-host"Size:" $item.Size

write-host"Status:" $item.Status

}

结果1：

Description: Disk drive

Device ID: \\.\PHYSICALDRIVE0

Interface Type: IDE

Media Type: Fixed hard disk media

Model: ST3320413AS

Partitions: 1

Size: 320070320640

Status: OK

Description: Disk drive

Device ID: \\.\PHYSICALDRIVE1

Interface Type: IDE

Media Type: Fixed hard disk media

Model: ST3320413AS

Partitions: 3

Size: 320070320640

Status: OK

例二：使用foreach 查询硬件信息（CPU）

$Processor=get-wmiobject-class Win32_Processor -namespace root\CIMV2

foreach($item in $Processor)

{

write-host"Caption:" $item.Caption

write-host"CPU Status:" $item.CpuStatus

write-host"Current Clock Speed:" $item.CurrentClockSpeed

write-host"Device ID:" $item.DeviceID

write-host"L2 Cache Size:" $item.L2CacheSize

write-host"L2 Cache Speed:" $item.L2CacheSpeed

write-host"Name:" $item.Name

}

结果2：

Caption: Intel64 Family 6 Model 42 Stepping7

CPU Status: 1

Current Clock Speed: 3101

Device ID: CPU0

L2 Cache Size: 1024

L2 Cache Speed:

Name: Intel(R) Core(TM) i5-2400 CPU @3.10GHz

例三：使用while;do…while监视进程状态

Notepad

            While(get-process-name notepad | select -Property Responding){}

$time =get-date

Write-Host"The Notepad failed to respond on:$time"

在此例下，若进程notepad出现未响应，则会产生屏幕输出。

使用do while表达：

notepad

do{}

While(get-process-name notepad | select -Property Responding)

$time =get-date

Write-Host"The Notepad failed to respond on:$time"

例四：利用do until进行交互

do

{

"Quit Now? (Y/N)"

$input=Read-Host

}

until($input-eq "Y")

运行结果：

PSC:\> do

>>{

>>     "Quit Now? (Y/N)"

>>     $input=Read-Host

>>}

>>until($input -eq "Y")

>>

QuitNow? (Y/N)

y

PSC:\>         

参考：http://marui.blog.51cto.com/1034148/294113