Powershell regex replacement expressions - regex

Question

I've followed the excellent solution in this article:
PowerShell multiple string replacement efficiency
to try and normalize telephone numbers imported from Active Directory. Here is an example:
$telephoneNumbers = #(
'[phone]',
'04 2356 3713'
'[phone]'
'61 (0) 3 9635 7899'
'[phone]'
)
# Build hashtable of search and replace values.
$replacements = #{
' ' = ''
'(0)' = ''
'+61' = '0'
'(02)' = '02'
'+65' = '001165'
'61 (0)' = '0'
}
# Join all (escaped) keys from the hashtable into one regular expression.
[regex]$r = #($replacements.Keys | foreach { [regex]::Escape( $_ ) }) -join '|'
[scriptblock]$matchEval = { param( [Text.RegularExpressions.Match]$matchInfo )
# Return replacement value for each matched value.
$matchedValue = $matchInfo.Groups[0].Value
$replacements[$matchedValue]
}
# Perform replace over every line in the file and append to log.
$telephoneNumbers |
foreach {$r.Replace($_,$matchEval)}
I'm having problems with the formatting of the match expressions in the $replacements hashtable. For example, I would like to match all +61 numbers and replace with 0, and match all other + numbers and replace with 0011.
I've tried the following regular expressions but they don't seem to match:
'^+61'
'^+[^61]'
What am I doing wrong? I've tried using \ as an escape character.

Answer 1

I've done some re-arrangement of this, I'm not sure if it works for your whole situation but it gives the right results for the example.
I think the key is not to try and create one big regex from the hashtable, but rather to loop over it and check the values in it against the telephone numbers.
The only other change I made was moving the ' ','' replacement from the hash into the code that prints the replacement phone number, as you want this to run in every scenario.
Code is below:
$telephoneNumbers = #(
'[phone]',
'04 2356 3713'
'[phone]'
'61 (0) 3 9635 7899'
'[phone]'
)
$replacements = #{
'(0)' = ''
'+61' = '0'
'(02)' = '02'
'+65' = '001165'
}
foreach ($t in $telephoneNumbers) {
$m = $false
foreach($r in $replacements.getEnumerator()) {
if ( $t -match [regex]::Escape($r.key) ) {
$m = $true
$t -replace [regex]::Escape($r.key), $r.value -replace ' ', '' | write-output
}
}
if (!$m) { $t -replace ' ', '' | write-output }
}
Gives:
0290237534
0423563713
0242757954
61396357899
00116565351943