[问题求助] 使用powershell 修改host文件

5i365

以前一直使用cmd批处理修改host文件, 刚刚在一段ps代码中添加修改host的代码, 就搜索了一下资源, 找到如下代码, 但是测试了一下, 不稳, 问题如下, 请高手指点, 感谢!
问题1. -enc ascii 这个参数居然会把原文件编码格式改为UTF8, 真是怪了
问题2.在已经有记录的情况下,仍然会追加记录
问题3.追加完后,用notepad2打开文件,提示换行符不一致

$IP_URL = "127.0.0.1 www.bing.com"

if ((Get-Content $env:windir\System32\drivers\etc\hosts | ?{ $_ -match "/s$IP_URL" }) -eq $null)
{
	"`n$IP_URL" | Out-File "$env:windir\System32\drivers\etc\hosts" -Append -enc ascii
	echo "已添加！"
}
else
{
	echo "已存在"
}
复制代码

5i365

回复 19# idwma


  嗯, 偶尔改手动更方便些, 改多台电脑时, 用批处理改不用到电脑旁边, 不用远程就改, 非常方便

idwma

这么绕的吗,直接用记事本打开不好吗

5i365

回复 15# idwma

分享老外写的, 用PS对话框的形式来改HOST, 里面有控件的位置, 尺寸之类的, 感觉应该可以去掉, 应该可以精简, 以前看到过有类似的, 才几行代码就行!

Add-Type -AssemblyName System.Windows.Forms
Add-Type -AssemblyName System.Drawing

$hostsfilelocation = "$env:windir\System32\drivers\etc\hosts"
$readhostsfile = Get-Content $hostsfilelocation

$form = New-Object System.Windows.Forms.Form
$form.Text = 'Update HOSTS File'
$form.Size = New-Object System.Drawing.Size(300, 200)
$form.StartPosition = 'CenterScreen'

$AddHosts = New-Object System.Windows.Forms.Button
$AddHosts.Location = New-Object System.Drawing.Point(55, 120)
$AddHosts.Size = New-Object System.Drawing.Size(90, 25)
$AddHosts.Text = 'Add Record'
$AddHosts.DialogResult = [System.Windows.Forms.DialogResult]::OK
$form.AcceptButton = $AddHosts
$form.Controls.Add($AddHosts)

$CancelButton = New-Object System.Windows.Forms.Button
$CancelButton.Location = New-Object System.Drawing.Point(170, 120)
$CancelButton.Size = New-Object System.Drawing.Size(75, 25)
$CancelButton.Text = 'Cancel'
$CancelButton.DialogResult = [System.Windows.Forms.DialogResult]::Cancel
$form.CancelButton = $CancelButton
$form.Controls.Add($CancelButton)

$Hostslabel = New-Object System.Windows.Forms.Label
$Hostslabel.Location = New-Object System.Drawing.Point(10, 20)
$Hostslabel.Size = New-Object System.Drawing.Size(280, 20)
$Hostslabel.Text = 'Enter New HOSTNAME/FQDN:'
$form.Controls.Add($Hostslabel)

$HoststextBox = New-Object System.Windows.Forms.TextBox
$HoststextBox.Location = New-Object System.Drawing.Point(10, 40)
$HoststextBox.Size = New-Object System.Drawing.Size(260, 20)
$form.Controls.Add($HoststextBox)

$IPlabel = New-Object System.Windows.Forms.Label
$IPlabel.Location = New-Object System.Drawing.Point(10, 60)
$IPlabel.Size = New-Object System.Drawing.Size(280, 20)
$IPlabel.Text = 'Enter IP:'
$form.Controls.Add($IPlabel)

$IPtextBox = New-Object System.Windows.Forms.TextBox
$IPtextBox.Location = New-Object System.Drawing.Point(10, 80)
$IPtextBox.Size = New-Object System.Drawing.Size(260, 20)
$form.Controls.Add($IPtextBox)

$form.Topmost = $true

$form.Add_Shown({ ($HoststextBox, $IPtextbox).Select() })

$result = $form.ShowDialog()

if ($result -eq [System.Windows.Forms.DialogResult]::OK)
{
	$inputhosts = $HoststextBox.Text
	$inputip = $IPtextBox.Text
	$newrecord = "$inputip $inputhosts"
	Add-Content -Path $hostsfilelocation -Value $newrecord
}
复制代码

5i365

回复 15# idwma


    搞定了, 把if移到上面去就行了

$Hosts = "$env:windir\System32\drivers\etc\hosts"
$a = gc $Hosts
if ($a[-1] -ne '') { ac $hosts '' }
$urls = @(
	"www.baidu.com"
	"www.bing.com"
) |
foreach{
	if ((gc $Hosts | Select-String $_) -eq $null)
	{
		ac $hosts "127.0.0.1 $_"
	}
}
复制代码

5i365

回复 15# idwma


    还是不行, 多了两个空行

idwma

回复 14# 5i365

$Hosts = "$env:windir\System32\drivers\etc\hosts"
$a=gc $Hosts
$urls = @(
	"www.baidu.com"
	"www.bing.com"
) |
foreach{
if($a[-1] -ne ''){ac $hosts ''}elseif ((gc $Hosts | Select-String $_) -eq $null)
	{
		ac $hosts "127.0.0.1 $_"
	}
}
复制代码

5i365

回复 13# idwma


    大侠, 使用ac和out-file都有这个问题, 最后一行没有空行, 就会追加到最后一行的末尾

idwma

$IP_URL = @(
        "127.0.0.1 www.bing.com"
        "127.0.0.1 www.sina.com"
)
$a=(Get-Content "$env:windir\System32\drivers\etc\hosts" | ?{ $_ -match "$($IP_URL -join '|')"}) -join '|'
if ($a -eq '')
{
	$IP_URL | ac "$env:windir\System32\drivers\etc\hosts"
	echo "已添加！"
}
else
{
	$IP_URL -notmatch "$a" | ac "$env:windir\System32\drivers\etc\hosts"
	echo "已存在"
}
复制代码

5i365

回复 9# idwma


    自己想了个办法, 但是如果host最后一行不是空行, 则第一行网址会跑到前一行的后面
测试了一下, add-content 确实有这个问题, 文件中最后一行没有空行, 就追加到最后一行的末尾了

$Hosts = "$env:windir\System32\drivers\etc\hosts"

$urls = @(
	"www.baidu.com"
	"www.bing.com"
) |
foreach{
	if ((gc $Hosts | Select-String $_) -eq $null)
	{
		ac $hosts "127.0.0.1 $_"
	}
}
复制代码

5i365

回复 9# idwma


    老外的代码参考:

# Uncomment lines with localhost on them:
$hostsPath = "$env:windir\System32\drivers\etc\hosts"
$hosts = get-content $hostsPath
$hosts = $hosts | Foreach {if ($_ -match '^\s*#\s*(.*?\d{1,3}.*?localhost.*)')
                           {$matches[1]} else {$_}}
$hosts | Out-File $hostsPath -enc ascii

# Comment lines with localhost on them:
$hosts = get-content $hostsPath
$hosts | Foreach {if ($_ -match '^\s*([^#].*?\d{1,3}.*?localhost.*)') 
                  {"# " + $matches[1]} else {$_}} |
         Out-File $hostsPath -enc ascii
复制代码

-----------------------------------------------------------------------------------------------

function setHostEntries([hashtable] $entries) {
    $hostsFile = "$env:windir\System32\drivers\etc\hosts"
    $newLines = @()

    $c = Get-Content -Path $hostsFile
    foreach ($line in $c) {
        $bits = [regex]::Split($line, "\s+")
        if ($bits.count -eq 2) {
            $match = $NULL
            ForEach($entry in $entries.GetEnumerator()) {
                if($bits[1] -eq $entry.Key) {
                    $newLines += ($entry.Value + '     ' + $entry.Key)
                    Write-Host Replacing HOSTS entry for $entry.Key
                    $match = $entry.Key
                    break
                }
            }
            if($match -eq $NULL) {
                $newLines += $line
            } else {
                $entries.Remove($match)
            }
        } else {
            $newLines += $line
        }
    }

    foreach($entry in $entries.GetEnumerator()) {
        Write-Host Adding HOSTS entry for $entry.Key
        $newLines += $entry.Value + '     ' + $entry.Key
    }

    Write-Host Saving $hostsFile
    Clear-Content $hostsFile
    foreach ($line in $newLines) {
        $line | Out-File -encoding ASCII -append $hostsFile
    }
}

$entries = @{
    'aaa.foo.local' = "127.0.0.1"
    'bbb.foo.local' = "127.0.0.1"
    'ccc.foo.local' = "127.0.0.1"
};
setHostEntries($entries)
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--------------------------------------------------------------

$domainName = "www.abc.com"
$rplaceStr = ""
$rHost = "C:\Windows\System32\drivers\etc\hosts"
$items = Get-Content $rHost | Select-String $domainName
Write-host $items
foreach( $item in $items)
{
(Get-Content $rHost) -replace $item, $rplaceStr| Set-Content $rHost
}
复制代码

5i365

回复 9# idwma


    刚试了下, 没有生效

idwma

$IP_URL = @(
        "127.0.0.1 www.bing.com"
        "127.0.0.1 www.sina.com"
)

$IP_URL -notmatch "$((Get-Content $env:windir\System32\drivers\etc\hosts | ?{ $_ -match "$($IP_URL -join '|')"}) -join '|')"|ac "$env:windir\System32\drivers\etc\hosts"
复制代码

5i365

回复 6# idwma


    大侠, 如果是一次添加多行条目, 应该怎么改, 例如:
$IP_URL = @(
        "127.0.0.1 www.bing.com"
        "127.0.0.1 www.sina.com"
)

5i365

回复 6# idwma


    感谢指点, 确实感觉多余了, 不加怎么可以? 我试了不行, 返回false