Parsing INI files in Powershell using regex - regex

Question

I'm trying to improve on the original solution (INI file parsing in PowerShell) so I can parse an INI file with entries like the example below.
[proxy]
; IP address and port number
server = 192.168.0.253
port = 8080
logfile=session.log ; log session
[user]
; default username and settings
name=J. Doe ;name
address="377 Sunrise Way;Santa Monica;CA" ; address
[program files]
root="C:\Program Files\Windows " ; path name
path="C:\Program Files\Windows;%windir" ; path name
;
[program]
root=C:\Program Files\Windows ; path name
path=C:\Program Files\Windows;%windir ; path name
I'm using the following powershell code to populate a nested hash table (if that is the right description) containing the name/value pairs for each section.
I have no problem dealing with the first section where I have lines ending in a comment, or with the value in the second section which contains spaces, but things go wrong when I try to mix quoted strings and comments.
Given that a string begins and ends with a double quote I think it should be possible to get the results I want but I am obviously missing something somewhere (I am a little new to this).
function Parse-INI-File() {
Param ([parameter()][string]$_file = '')
# Don't prompt to continue if '-Debug' is specified.
If ($DebugPreference -eq "Inquire") {$DebugPreference = "Continue"}
$_settings=#{}
switch -Regex -file $_file {
'(?:^ ?\[\s*(?<section>[^\s]+[^#;\r\n\[\]]+)\s*\])' {
$_section = $Matches.section.trim()
$_settings[$_section] = #{}
}
'(?:^\s*?(?<name>[^\[\]\r\n=#;]+))(?: ?=\s*"?(?<value>[^;#\\\r\n]*(?:\\.[^"#\\\r\n]*)*))' {
$_name, $_value = $Matches.name.trim(), $matches.value.trim()
$_settings[$_section][$_name] = $_value
Write-Debug "/$_section/ /$_name//$_value/" # Debug
}
}
$_settings
}
$_file='./ini-example.ini'
$_output=Parse-INI-File -Debug ($_file)
What I'd like is for the parsing of the sample ini file to result in the following name/value pairs:
DEBUG: /proxy/ /server//192.168.0.253/
DEBUG: /proxy/ /port//8080/
DEBUG: /proxy/ /logfile//session.log/
DEBUG: /user/ /name//J. Doe/
DEBUG: /user/ /address//377 Sunrise Way;Santa Monica;CA/
DEBUG: /program files/ /root//C:\Program Files\Windows/
DEBUG: /program files/ /path//C:\Program Files\Windows;%windir/
DEBUG: /program/ /root//C:\Program Files\Windows/
DEBUG: /program/ /path//C:\Program Files\Windows/
I don't mind if quoted strings include the original quotes or not.
Thank you.
Updated 10 Sep 19 - I have tried the Get-IniContent function in the psini module, but it doesn't ignore comments at the end of a line.
PS C:\> $_output = Get-IniContent (".\ini-example.ini")
PS C:\> $_output["program files"]
Name Value
---- -----
root "C:\Program Files\Windows "' ; path name
path "C:\Program Files\Windows;;%windir" ; path name
Comment1 ;
PS C:\>

Answer 1

Think I've solved it, there is probably a better solution but I solved the problem by using a separate regex for quoted strings - this complicates the logic a bit but seems to solve the problem reliably.
function Parse-INI-File() {
Param ([parameter()][string]$_file = '')
# Don't prompt to continue if '-Debug' is specified.
If ($DebugPreference -eq "Inquire") {$DebugPreference = "Continue"}
$_settings=#{}
switch -Regex -file $_file {
'(?:^ ?\[\s*(?<section>[^\s]+[^\r\n\[\]]+)\s*\])' {
$_section = $Matches.section.trim()
$_settings[$_section] = #{}
#Write-Debug "1/$_section/" # Debug
}
'(?:^\s*?(?<name>[^\[\]\r\n]+))(?: ?=\s*(?<value>[^";#\\\r\n]*(?:\\.[^";#\\\r\n]*)*))' {
If ($matches.value -ne '' ) {
$_name, $_value = $Matches.name.trim(), $matches.value.trim()
$_settings[$_section][$_name] = $_value
Write-Debug "2/$_section//$_name//$_value/" # Debug
}
}
'(?:^\s*?(?<name>[^\[\]\r\n]+))(?: ?=\s*(?<value>\"+[^\"\r\n]*\")*)' {
#If ($matches.value -ne $null ) {
If (-not [string]::IsNullOrEmpty($matches.value)) {
$_name, $_value = $Matches.name.trim(), $matches.value.trim()
$_settings[$_section][$_name] = $_value
Write-Debug "3/$_section//$_name//$_value/" # Debug
}
}
}
$_settings
}
This seems to produces the results I'd expect
PS C:\> $_output = Parse-INI-File -Debug (".\ini-example.ini")
DEBUG: 2/proxy//server//192.168.0.253/
DEBUG: 2/proxy//port//8080/
DEBUG: 2/proxy//logfile//session.log/
DEBUG: 2/user//name//J. Doe/
DEBUG: 3/user//address//"377 Sunrise Way;Santa Monica;CA"/
DEBUG: 3/program files//root//"C:\Program Files\Windows "/
DEBUG: 3/program files//path//"C:\Program Files\Windows;%windir"/
DEBUG: 2/program//root//C:\Program Files\Windows/
DEBUG: 2/program//path//C:\Program Files\Windows/
PS C:\> $_output["user"]
Name Value
---- -----
name J. Doe
address "377 Sunrise Way;Santa Monica;CA"
PS C:\>
Note that if there are multiple values with the same name in a section then only the last value is returned (try parsing system.ini to see what I mean)