Question

我有一个csv文件中的计算机列表，每周日上午9点进行系统映像备份。

hostname    macaddr            comments
TOTO-01     842B2BB728C1       Server Room
KOKO-14     842B2BB7420F       Server Room
FOFO-25     001AA0485902       Server Room

我正在尝试创建一个powershell脚本，打开列表中的所有计算机，并进行一些检查以查看备份是否成功。

我遇到的问题是，如果任何一项检查失败，我希望脚本移动到列表中的下一台计算机。

我的守则如下：

param 
(
    [Io.FileInfo]$csvFile = 'C:\Scripts\VipBackUp.csv',
    [Io.FileInfo]$WolCmdExe = 'C:\mgmt\tools\WolCmd.exe'
)

######Get the current date - 20 hours.
$GetCurrentDate = (get-date) - (new-timespan -days 6)
$GetCurrentDate

#####Turn on PC
function TurnOnPc
{
    $TurnOn = invoke-expression "$WolCmdExe $macaddr 192.168.1.0 255.255.255.255"
    write-host ""
    write-host "Turning on $hostname.."
    if($TurnOn)
    {
        write-host "$comp has been turned on"
        write-host ""
    }
    else
    {
        $global:PCTurnOnError = "Yes"
    }
}

#####Test PC connectivity
function PingPC
{
    Start-Sleep  3
    $ping = test-connection -Computername $hostname -count 5 -quiet
    write-host "Checking connection for $hostname"
    if($ping)
    {
        write-host "Connection Found for $hostname"
        write-host ""
    }
    else                          
    {
        $global:PCPingError = "Yes"
        Write-Host "$hostname unreachable"
        write-host ""
    }   
}

#####Check backup files to see if they have been written to.
function CheckWritePC
{
    $global:OriginalWrite = Get-ChildItem "C:\Powershell Testing\$hostname.txt"
    $global:OriginaSize = (Get-ChildItem "C:\Powershell Testing\$hostname.txt").length
    write-host ""
    write-host "Checking the following PC if it has been writen to: $hostname"
    start-sleep 15
    $global:NewWrite = Get-ChildItem "C:\Powershell Testing\$hostname.txt"
    $global:Newsize = (Get-ChildItem "C:\Powershell Testing\$hostname.txt").length
    $compareWrite = compare-object $OriginalWrite $NewWrite -property Name, lastwritetime | where-object {$_.SideIndicator -eq "=>"}
    if($compareWrite)
    {
        write-host "$hostname has been modified"
        $global:HasBeenModified = "Yes"
        write-host ""
    }
    else
    {
        write-host "$hostname has not been modified"
        $global:HasBeenModified = "No"
        write-host ""
    }
}

#####Check to see if an error log has been recorded.
function CheckEventLog
{
    write-host "Checking the following PC for error logs: $hostname"
    $hostname | out-null; get-winevent -providername 'Microsoft-Windows-Backup' -computername $hostname | where {$_.id -eq "8" -and $_.timecreated -ge $GetCurrentDate}
    $hostname | out-null; if(get-winevent -providername 'Microsoft-Windows-Backup' -computername $hostname | where {$_.id -eq "8" -and $_.timecreated -ge $GetCurrentDate})
    { 
        write-host "$comp received the following eventlog ID: 8"
        $global:EventError = "Yes"
        write-host ""
    }
}

#####Check to see that the size has increased or decreased more than 5%.
function CalculatePercentageDifference
{
    $range = 5..-5
    write-host "Checking the size difference for $hostname."
    $b = $global:Newsize - $global:OriginaSize
    $c = $b/$global:OriginaSize * 100
    $RoundedNumber = [system.Math]::Round($c, 0)
    #write-host $RoundedNumber "%"
    if($range -contains $RoundedNumber)
    {
        write-host "$RoundedNumber%: There has not been a big enough change in the file size"
        $global:SizeIsTooSmall = "Yes"
        write-host ""
    }
    else
    {
        write-host "$RoundedNumber% falls within normal parameters."
        write-host ""
    }
}

#####################END FUNCTIONS###################################################

Import-Csv $csvFile.FullName | %  {
    $hostname = $_.hostname
    $macaddr = $_.macaddr

    Foreach ($_.hostname in $file) {
        if ($ErrorMessage){
            $foreach.moveNext()

            TurnOnPC
            if($global:PCTurnOnError -eq 'Yes')
            {
                #write-host "$hostname did not turn on"
                $ErrorMessage = "$hostname Did not turn on"
                write-host ""
                #email
                continue
            }

            PingPC
            if($global:PCPingError -eq 'Yes')
            {
                $ErrorMessage =  "$hostname is unreachable"
                write-host ""
                #email
                continue
            }

            CheckWritePC
            if($HasBeenModified -eq 'No')
            {
                #Write-host "No write"
                $ErrorMessage = "  Backup file has not been written to" 
                #email
                continue
            }

            CheckEventLog
            if($EventError -eq 'Yes')
            {
                $ErrorMessage = "  Received an '8' winlog message"
                #email
                continue
            }
            else
            {
                write-host "No event errors recorded"
                write-host ""
            }

            CalculatePercentageDifference
            if($SizeIsTooSmall -eq 'Yes')
            {
                $ErrorMessage = "  The file size has not changed enough"
                #email
                continue
            }
        }
    }
}

Answer 1

您没有进行任何错误处理。如果您在PowerShell中遇到终止错误，则需要使用trap或使用try/catch来捕获它。您还可以在使用cmdlet时使用-ErrorAction SilentlyContinue参数。

终止错误将停止所有执行。因此，您需要确定发生终止错误的位置并添加错误处理代码。

例如：

try {
    1/$null
} catch {
    Write-Host ("The error was: " + $_)
}
Write-Host "Continuing..."

此try / catch构造将显示错误消息，但允许继续执行。

另一个例子：

trap {
    Write-Host ("The error was: " + $_)
}
1/$null
Write-Host "Continuing..."

Answer 2

这是continue语句的演示：

foreach ($i in 1..5) { 
  if ($i -eq 3) { # "error"
    continue 
  } 

  $i 
}

# output
1
2
4
5

如果错误，Powershell foreach将转移到下一个

2 个答案: