Powershell - How to get data within delimiters and manipulate the data - regex

Question

I'm using Powershell to write a script which based on an input file splits each section and manipulates the underlying data.
In practical terms, i have a TXT file which is formatted like so:
-------Group_Name_1-------
member: Name:Host1 Handle:123
member: Name:Host2 Handle:213
member: Name:Host3 Handle:321
-------Group_Name_2-------
member: Name:Host10 Handle:1230
member: Name:Host20 Handle:2130
Group (member of): Firewall subnet
etc...
So far, I've come up with the following script:
$filepath = 'C:\test.txt'
$getfile = Get-Content $filepath -Raw
$regex_group_name = '.*-------'
foreach($object in $splitfile){
$lines = $object.Split([Environment]::NewLine)
$data_group_name = #($lines) -match $regex_group_name
$data_group_value = $data_group_name -replace '-------' , ''
Write-Host $data_group_value
}
I'm trying to achieve the following output for each group (for example):
add group name Group_Name_1 members.1 "Host1" members.2 "Host2" members.3 "Host3" groups.1 "Firewall Subnet"
And I'm stuck in 2 parts:
1) The script above, obviously won't work, because the "split" function will basically remove the group name: how can I approach this problem in order to get the desired output?
2) I have no idea on how to change the output in order to reflect the effective number of members (if the members are 2, it will only output members.1 and members.2; alternatively members.1, members.2, members.3 etc...).
Thanks in advance for your help.

Answer 1

I would solve this in two steps.
First, parse the file into a data structure (in this case, an array of PSCustomObjects)
Then, convert those into the command strings.
Assuming this $fileContent
$fileContent = "-------Group_Name_1-------
member: Name:Host1 Handle:123
member: Name:Host2 Handle:213
member: Name:Host3 Handle:321
-------Group_Name_2-------
member: Name:Host10 Handle:1230
member: Name:Host20 Handle:2130
Group (member of): Firewall subnet
etc..."
We can build step 1 like this:
$sections = $fileContent -split "(?m)^-------"
$groups = foreach ($section in $sections) {
$group = [pscustomobject]#{
Name = ([regex]"(.*)-------").Match($section).Groups[1].Value
Members = #(([regex]"member: Name:(\S+)").Matches($section) | ForEach-Object {
$_.Groups[1].Value
})
MemberOf = #(([regex]"Group \(member of\): (.+)").Matches($section) | ForEach-Object {
$_.Groups[1].Value
})
}
if ($group.Name) {
$group
}
}
# intermediate results (parsed group structure)
$groups
This prints
Name Members MemberOf
---- ------- --------
Group_Name_1 {Host1, Host2, Host3} {}
Group_Name_2 {Host10, Host20} {Firewall subnet}
Now it's easy to turn this into a different format:
$commands = foreach ($group in $groups) {
$str = "add group "
$str += "name `"$( $group.Name )`" "
$i = 1
foreach ($member in $group.Members) {
$str += "members.$i `"$member`" "
$i++
}
$i = 1
foreach ($memberOf in $group.MemberOf) {
$str += "groups.$i `"$memberOf`" "
$i++
}
$str.Trim()
}
# final results (command strings)
$commands
Which prints:
add group name "Group_Name_1" members.1 "Host1" members.2 "Host2" members.3 "Host3"
add group name "Group_Name_2" members.1 "Host10" members.2 "Host20" groups.1 "Firewall subnet"