Could regex be used in this PowerShell script? - regex

Question

I have the following code, used to remove spaces and other characters from a string $m, and replace them with periods ('.'):
Function CleanupMessage([string]$m) {
$m = $m.Replace(' ', ".") # spaces to dot
$m = $m.Replace(",", ".") # commas to dot
$m = $m.Replace([char]10, ".") # linefeeds to dot
while ($m.Contains("..")) {
$m = $m.Replace("..",".") # multiple dots to dot
}
return $m
}
It works OK, but it seems like a lot of code and can be simplified. I've read that regex can work with patterns, but am not clear if that would work in this case. Any hints?

Answer 1

Use a regex character class:
Function CleanupMessage([string]$m) {
return $m -replace '[ ,.\n]+', '.'
}
EXPLANATION
--------------------------------------------------------------------------------
[ ,.\n]+ any character of: ' ', ',', '.', '\n' (newline)
(1 or more times (matching the most amount
possible))

Answer 2

Solution for this case:
cls
$str = "qwe asd,zxc`nufc..omg"
Function CleanupMessage([String]$m)
{
$m -replace "( |,|`n|\.\.)", '.'
}
CleanupMessage $str
# qwe.asd.zxc.ufc.omg
Universal solution. Just enum in $toReplace what do you want to replace:
cls
$str = "qwe asd,zxc`nufc..omg+kfc*fox"
Function CleanupMessage([String]$m)
{
$toReplace = " ", ",", "`n", "..", "+", "fox"
.{
$d = New-Guid
$regex = [Regex]::Escape($toReplace-join$d).replace($d,"|")
$m -replace $regex, '.'
}
}
CleanupMessage $str
# qwe.asd.zxc.ufc.omg.kfc*.