How delete a line having a word quickly in multiple large files using powershell

问题

How delete a line having a word quickly in multiple large files using PowerShell

i am using the below code but it take long time

   $files = Get-ChildItem "D:\mjautomation\v19.0\filesdd\"

foreach ($file in $files) {
   $c = Get-Content $file.fullname | where { $_ -notmatch "deletethisline" }
   $c | Set-Content $file.fullname

回答1:

The following should be reasonably fast due to use of switch -File, but note that it requires reading each file into memory as a whole (minus the excluded lines):

foreach ($file in Get-ChildItem -File D:\mjautomation\v19.0\filesdd) {
  Set-Content $file.FullName -Value $(
    switch -Regex -File $file.FullName {
      'deletethisline' {} # ignore
      default { $_ } # pass line through
    }
  )
}

If you don't want to read each file into memory in (almost) full, use a [System.IO.StreamWriter] instance, as shown in this answer instead of Set-Content to write to a temporary file, and then replace the original file.

Doing so has the added advantage of avoiding the small risk of data loss that writing back to the original file via in-memory operations bears.

If you want to make do with the - slower - Get-Content cmdlet, use the following; the same caveats as above apply:

foreach ($file in Get-ChildItem -File D:\mjautomation\v19.0\filesdd) {
  Set-Content $file.FullName -Value (
    @(Get-Content $file.FullName) -notmatch 'deletethisline'
  )
}

Note that as an alternative to the foreach loop you can use a single pipeline with the ForEach-Object cmdlet - Get-ChildItem ... | ForEach-Object { <# work with $_ #> } - but doing so is slower (though in many cases that won't matter).

来源：https://stackoverflow.com/questions/59758144/how-delete-a-line-having-a-word-quickly-in-multiple-large-files-using-powershell

标签

powershell