CODEWITHSUNDEEP
windowspowershellhosts
Herysia
Herysia

Reputation: 21

Adding/Removing hosts file entry using powershell corrupts the file

I'm trying to add or remove a specific entry in Windows hosts file using powershell, but when I do this, it works for some time, and after a while it gets edited again (when Windows reads it, I guess), and it becomes corrupted (displays chinese characters).

I've tried using parts of a code i found here. It allows me to edit the file properly and the entry is effective, until it gets corrupted.

I'm doing this to add the entry:

If ((Get-Content "$($env:windir)\system32\Drivers\etc\hosts" ) -notcontains "111.111.111.111 example.com")  
 {ac -Encoding UTF8  "$($env:windir)\system32\Drivers\etc\hosts" "111.111.111.111 example.com" }

Here is what the file looks like after it gets corrupted:

Thanks for your help.

Solved: Remove -Encoding UTF8

Upvotes: 2

Views: 6810

Answers (1)

Theo
Theo

Reputation: 61013

Because as it states in the comment of the hosts file, "The IP address and the host name should be separated by at least one space.", trying to find a string with exactly one space character in between could return false.

I think it would be better to use Regex for this as it allows matching on more than one space character to separate the IP from the host name. However, this does require the usage of [Regex]::Escape() on both parts of the entry as they contain regex special characters (the dot).

Something like this:

$hostsFile  = "$($env:windir)\system32\Drivers\etc\hosts"
$hostsEntry = '111.111.111.111 example.com'

# split the entry into separate variables
$ipAddress, $hostName = $hostsEntry -split '\s+',2
# prepare the regex
$re = '(?m)^{0}[ ]+{1}' -f [Regex]::Escape($ipAddress), [Regex]::Escape($hostName)

If ((Get-Content $hostsFile -Raw) -notmatch $re) {
    Add-Content -Path $hostsFile -Value $hostsEntry
}

Upvotes: 3

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