你可以尝试这样做:

$path = "C:\testFile.txt"
$word = "searchword"
$replacement = "ReplacementText"
$text = get-content $path 
$newText = $text -replace $word,$replacement
$newText > $path

对Set-Content命令的小修正。如果没有找到搜索的字符串，Set-Content命令将清空目标文件。

您可以首先验证要查找的字符串是否存在。否则，它将无法取代任何东西。

If (select-string -path "c:\Windows\System32\drivers\etc\hosts" -pattern "String to look for") `
    {(Get-Content c:\Windows\System32\drivers\etc\hosts).replace('String to look for', 'String to replace with') | Set-Content c:\Windows\System32\drivers\etc\hosts}
    Else{"Nothing happened"}

有点旧和不同，因为我需要在特定文件名的所有实例中更改某一行。

此外，Set-Content没有返回一致的结果，所以我不得不求助于Out-File。

下面的代码:

$FileName =''
$OldLine = ''
$NewLine = ''
$Drives = Get-PSDrive -PSProvider FileSystem
foreach ($Drive in $Drives) {
    Push-Location $Drive.Root
        Get-ChildItem -Filter "$FileName" -Recurse | ForEach { 
            (Get-Content $_.FullName).Replace($OldLine, $NewLine) | Out-File $_.FullName
        }
    Pop-Location
}

这是最适合我的PowerShell版本:

Major.Minor.Build.Revision 5.1.16299.98

(Get-Content file.txt) | 
Foreach-Object {$_ -replace '\[MYID\]','MyValue'}  | 
Out-File file.txt

注意(Get-Content file.txt)周围的括号是必需的:

Without the parenthesis the content is read, one line at a time, and flows down the pipeline until it reaches out-file or set-content, which tries to write to the same file, but it's already open by get-content and you get an error. The parenthesis causes the operation of content reading to be performed once (open, read and close). Only then when all lines have been read, they are piped one at a time and when they reach the last command in the pipeline they can be written to the file. It's the same as $content=content; $content | where ...

你可以尝试这样做:

$path = "C:\testFile.txt"
$word = "searchword"
$replacement = "ReplacementText"
$text = get-content $path 
$newText = $text -replace $word,$replacement
$newText > $path

如果需要替换多个文件中的字符串:

值得注意的是，这里发布的不同方法在完成所需时间方面可能有很大不同。对我来说，我经常有大量的小文件。为了测试哪个性能最好，我在40,693个单独的文件中提取了5.52 GB(5,933,604,999字节)的XML，并运行了我在这里找到的三个答案:

## 5.52 GB (5,933,604,999 bytes) of XML files (40,693 files) 
$xmls = (Get-ChildItem -Path "I:\TestseT\All_XML" -Recurse -Filter *.xml).FullName

#### Test 1 - Plain Replace
$start = Get-Date
foreach ($xml in $xmls) {
    (Get-Content $xml).replace("'", " ") | Set-Content $xml
}
$end = Get-Date
New-TimeSpan –Start $Start –End $End
# TotalMinutes: 103.725113128333

#### Test 2 - Replace with -Raw
$start = Get-Date
foreach ($xml in $xmls) {
    (Get-Content $xml -Raw).replace("'", " ") | Set-Content $xml
}
$end = Get-Date
New-TimeSpan –Start $Start –End $End
# TotalMinutes: 10.1600227983333

#### Test 3 - .NET, System.IO
$start = Get-Date
foreach ($xml in $xmls) {
    $txt = [System.IO.File]::ReadAllText("$xml").Replace("'"," ") 
    [System.IO.File]::WriteAllText("$xml", $txt)
}
$end = Get-Date
New-TimeSpan –Start $Start –End $End
# TotalMinutes: 5.83619516833333