PowerShell, parsing, problem using a specific string with -match/-like and -split - string

I have a variable that is filled with several lines of text and I am trying to parse the data from it. Now around the middle of the text is a specific string "Reference(s) :" and I need to get everything from above this specific string. However every way I have tried has failed.
I tried making it a delimiter
$Var.split("Reference(s) :")
I tried the below 2 options just to try to capture that one line (because if I can do this, then I know I can pull everything before it).
$Var.split("`n") | Where-Object {$_ -match "Reference(s) :"}
and
$Var.split("`n") | Where-Object {$_ -like "*Reference(s) :*"}
and I've tried some if statements (Where $_ is a single line of text)
If ($_ -like "*Reference(s) :*") {some logic}
I cannot just match "Reference" because that word appears elsewhere in the text....and I am needing this to process several instances of this text.
I think the problem has to do with the parenthesis, the space, and the colon (special characters). I did try preceding each special character with a ` but that did not seem to work.
Anyone have any ideas? There has to be a way to match special characters, I just haven't found it yet.

If $var is truly a single string, you can use -split at your reference point and then retrieve the first split string ([0]). This will retrieve everything from the start of the string until the split point.
($Var -split 'Reference\(s\) :')[0]
Since -split uses regex matching, you must backslash escape regex special characters to match them literally. Here ( and ) are special.
In the future, you can just process your match string using [regex]::Escape('String'), and it will do all the escaping for you.
If you want the line just before the reference point, you can convert your string into an array. Then return the line above the matching line.
foreach ($line in ($Var -split '\r?\n')) {
if ($line -match 'Reference\(s\) :') {
$lastLine
} else {
$lastLine = $line
}
}

Apologies I know this is very similar to AdminOfThings good answer. I was already testing it so figured I'd post.
$text =
#"
Line1
Line2
Line3
Line4
Line5
Reference(s) :
Line5
Line7
Line8
Line9
Line10
"#
($text -Split "Reference\(s\) :")[0]
This also works, but for various reasons it's recommended to stay with the PowerShell native split operator:
$text.Split([String[]]"Reference(s) :", [StringSplitOptions]::None )[0]

Here it is using the where method. You can just use -eq instead of -match if that's the whole line.
get-content file
before1
before2
before3
Reference(s) :
after1
after2
after3
(get-content file).where({$_ -match [regex]::escape('Reference(s) :')},'Until')
before1
before2
before3

Related

Powershell multiple string replacement using while cycle

I am trying to solve a somewhat weird problem: I need to replace strings within a raw content by strings from the same content that meet a certain matching criteria. The input data look like this:
apple-beta
apple-alpha_orange-beta
apple-alpha_orange-alpha_cherry-beta
apple-alpha_orange-alpha_kiwi-beta
apple-alpha_orange-alpha_mango-beta
abcd-alpha_efgh-beta
abcd-alpha_efgh-alpha_ijkl-beta
abcd-alpha_efgh-alpha_mnop-beta
The replacment should work as follows: look for all "-beta" strings in the content and delete all according "-alpha" strings (eg because there is "orange-beta" already => all "orange-alpha" should be deleted, because there is "apple-beta" already => all "apple-alpha" should be deleted etc.). The result would look like this:
apple-beta
_orange-beta
__cherry-beta
__kiwi-beta
__mango-beta
abcd-alpha_efgh-beta
abcd-alpha__ijkl-beta
abcd-alpha__mnop-beta
I have tried to achieve this with a number of awkward single replacements and temporary file storages as well as with a while-construction that doesn't work at all:
$whileinput = get-content -raw C:\content-input.txt
while ($whileinput -match "\w+-beta") {
$fullval = $whileinput -match "\w+-beta" -replace "-beta","-alpha"
$whileinput = $whileinput -replace '$fullval',''
}
Any help is very appreciated!
Daniel
I would find all your beta items. Then replace the corresponding alpha items.
$data = Get-Content C:\content-input.txt
$betas = ([regex]::Matches($data,'[^_]*?(?=-beta)').Value -ne '' | Foreach-Object {
[regex]::Escape($_)} ) -join '|'
$data -replace "($betas)-alpha"
Explanation:
[regex]::Matches().Value returns only the matched texts.
[^_]*? lazily matches consecutive characters that are not _. (?=-beta) is a positive lookahead for the text -beta but doesn't include the text in the match.
-ne '' is to filter out blank output.
[regex]::Escape() is not necessarily needed in this case. But it is good practice when your text may have special regex characters that you want to match literally.
$betas contains | delimited items because | is the regex OR. Using () to surround the $betas string allows one of those words to be fully matched before matching -alpha in the replacement.
Get-Content gets the entire contents of a file into a variable, so if anything in your file matches that pattern, it'll loop infinitely (because the contents of the file always match your pattern).
PowerShell is heavily based around the concept of the "pipeline" which you can use in conjunction with the Foreach-Object cmdlet to iterate over each line in a file.
I'm not quite clear on what you want the regexes to do, but I don't think the ones you have will do what you want. Try this.
Get-Content -raw C:\content-input.txt | Foreach-Object {
if($_ -match 'beta$') {
$out+=$_ -replace '\w+-alpha',''
}
}
$out | Out-File .\path-to-output.txt
$_ is the default "pipeline variable" aka the current item in the iteration - in this case the current line. Now at least your loop is working!

-replace (value) with an escape char?

I need to pull first and last names from accounts that were very poorly named from the previous IT administrator and recreate them in the same source OU.
There are characters in the account name I that I cant seem to get past. I need to pull First,Last and the remaining DN so I can recreate the account in the same OU structure without. For testing I'm only using one user in one OU, but there will be many different OU structures. "\" and "(Vendor)" are causing
My end goal is to feed the script a list of Accounts DN and recreate the account without the undesired "\" and "(vendor)" and do first.last or some variation of that.
$source = "CN=last\, first (Vendor),OU=vendors,DC=somecompany,DC=com"
$arg = "(vendor)"
($source -split ',*..=')[1].Remove($arg)
I've also tried
($source -split ',*..=')[1] -replace "`(Vendor)'", ""
The brackets and \ seem to cause everything I've tried to fail. I've searched and there doesnt seem to be a simple escape char like ^ for Batch files.
The backtick is the escape character usually for just powershell code. In the regex though, you will want to double your backslashes.
$source = "CN=last\, first (Vendor),OU=vendors,DC=somecompany,DC=com","CN=last\, first (Vendor),OU=vendors,DC=somecompany,DC=com"
$r = ($source[0] -split ',*..=|\\,').Replace("(Vendor)","").Where({ $_ -ne ''})
$r
For .remove() the argument is supposed to be a number, the number or characters to display of a string (and removing every character after the number of characters you give specify). Feeding it a string when it's expecting an int will just error so I used .replace() instead.
.remove() takes a number as an argument:
($source -split ',*..=')[1].Remove
OverloadDefinitions
-------------------
string Remove(int startIndex, int count)
string Remove(int startIndex)
Using backslashes to escape regex characters:
($source -split ',*..=')[1] -replace "\(Vendor\)", ""
last\, first
Confirmed by
[regex]::escape("(Vendor)")
\(Vendor\)
Thanks for all of the help.
$source = "CN=Doe\, John (Vendor),OU=vendors,DC=somecompany,DC=com"
$r = ($source -split ',*..=|\\,').Replace("(Vendor)","").Where({ $_ -ne ''})
$first = $r[1].replace(" ","")
$last = $r[0].replace(" ","")
$DN = ($source -split "OU=",2)[1]
$DN = "OU=" + $DN
$first
$last
$DN

How to parse string in powershell

I have a Powershell command that outputs multiple lines.
I want to output only one line that contains the name of a .zip file.
Currently, all lines are returned when substring .zip is found:
$p.Start() | Out-Null
$p.WaitForExit()
$output = $p.StandardOutput.ReadToEnd()
$output += $p.StandardError.ReadToEnd()
foreach($line in $output)
{
if($line.Contains(".zip"))
{
$line
}
}
Since you're using .ReadToEnd(), $output receives a single, multi-line string, not an array of lines.
You must therefore split that string into individual lines yourself, using the -split operator.
You can then apply a string-comparison operator such as -match or -like directly to the array of lines to extract matching lines:
# Sample multi-line string.
$output = #'
line 1
foo.zip
another line
'#
$output -split '\r?\n' -match '\.zip' # -> 'foo.zip'
-split is regex-based, and regex \r?\n matches newlines (line breaks) of either variety (CRLF, as typical on Windows, as well as LF, as typical on Unix-like platforms).
-match is also regex-based, which is why the . in \.zip is \-escaped, given that . is a regex metacharacter (it matches any character other than LF by default).
Note that -match, like PowerShell in general, is case-insensitive by default, so both foo.zip and foo.ZIP would match, for instance;
if you do want case-sensitivity, use -cmatch.
As an aside:
I wonder why you're running your command via a [System.Diagnostics.Process] instance, given that you seem to be invoking synchronously while capturing its standard streams.
PowerShell allows you to do that much more simply by direct invocation, optionally with redirection:
$output = ... 2>&1

Multi-Line String to Single-Line String conversion in PowerShell

I have a text file that has multiple 'chunks' of text. These chunks have multiple lines and are separated with a blank line, e.g.:
This is an example line
This is an example line
This is an example line
This is another example line
This is another example line
This is another example line
I need these chunks to be in single-line format e.g.
This is an example lineThis is an example lineThis is an example line
This is another example lineThis is another example lineThis is another example line
I have researched this thoroughly and have only found ways of making whole text files single-line. I need a way (preferably in a loop) of making an array of string chunks single-line. Is there any way of achieving this?
EDIT:
I have edited the example content to make it a little clearer.
# create a temp file that looks like your content
# add the A,B,C,etc to each line so we can see them being joined later
"Axxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Cxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Dxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Exxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Fxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Gxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Ixxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" | Set-Content -Path "$($env:TEMP)\JoinChunks.txt"
# read the file content as one big chunk of text (rather than an array of lines
$textChunk = Get-Content -Path "$($env:TEMP)\JoinChunks.txt" -Raw
# split the text into an array of lines
# the regex "(\r*\n){2,}" means 'split the whole text into an array where there are two or more linefeeds
$chunksToJoin = $textChunk -split "(\r*\n){2,}"
# remove linefeeds for each section and output the contents
$chunksToJoin -replace '\r*\n', ''
# one line equivalent of above
((Get-Content -Path "$($env:TEMP)\JoinChunks.txt" -Raw) -split "(\r*\n){2,}") -replace '\r*\n', ''
A bit of a fudge:
[String] $strText = [System.IO.File]::ReadAllText( "c:\temp\test.txt" );
[String[]] $arrLines = ($strText -split "`r`n`r`n").replace("`r`n", "" );
This relies on the file having Windows CRLFs.
There a several ways to approach a task like that. One is to use a regular expression replacement with a negative lookahead assertion:
(Get-Content 'C:\path\to\input.txt' | Out-String) -replace "`r?`n(?!`r?`n)" |
Set-Content 'C:\path\to\output.txt'
You could also work with a StreamReader and StreamWriter:
$reader = New-Object IO.StreamReader 'C:\path\to\input.txt'
$writer = New-Object IO.StreamWriter 'C:\path\to\output.txt'
while ($reader.Peek() -gt 0) {
$line = $reader.ReadLine()
if ($line.Trim() -ne '') {
$writer.Write($line)
} else {
$writer.WriteLine()
}
}

PowerShell to remove text from a string

What is the best way to remove all text in a string after a specific character? In my case "=" and after another character in my case a ,, but keep the text between?
Sample input
=keep this,
Another way to do this is with operator -replace.
$TestString = "test=keep this, but not this."
$NewString = $TestString -replace ".*=" -replace ",.*"
.*= means any number of characters up to and including an equals sign.
,.* means a comma followed by any number of characters.
Since you are basically deleting those two parts of the string, you don't have to specify an empty string with which to replace them. You can use multiple -replaces, but just remember that the order is left-to-right.
$a="some text =keep this,but not this"
$a.split('=')[1].split(',')[0]
returns
keep this
This should do what you want:
C:\PS> if ('=keep this,' -match '=([^,]*)') { $matches[1] }
keep this
This is really old, but I wanted to add my slight variation for anyone else who may stumble across this. Regular expressions are powerful things.
To keep the text which falls between the equal sign and the comma:
-replace "^.*?=(.*?),.*?$",'$1'
This regular expression starts at the beginning of the line, wipes all characters until the first equal sign, captures every character until the next comma, then wipes every character until the end of the line. It then replaces the entire line with the capture group (anything within the parentheses). It will match any line that contains at least one equal sign followed by at least one comma. It is similar to the suggestion by Trix, but unlike that suggestion, this will not match lines which only contain either an equal sign or a comma, it must have both in order.
I referenced #benjamin-hubbard 's answer above to parse the output of dnscmd for A records, and generate a PHP "dictionary"/key-value pairs of IPs and Hostnames. I strung multiple -replace args together to replace text with nothing or tab to format the data for the PHP file.
$DnsDataClean = $DnsData `
-match "^[a-zA-Z0-9].+\sA\s.+" `
-replace "172\.30\.","`$P." `
-replace "\[.*\] " `
-replace "\s[0-9]+\sA\s","`t"
$DnsDataTable = ( $DnsDataClean | `
ForEach-Object {
$HostName = ($_ -split "\t")[0] ;
$IpAddress = ($_ -split "\t")[1] ;
"`t`"$IpAddress`"`t=>`t'$HostName', `n" ;
} | sort ) + "`t`"`$P.255.255`"`t=>`t'None'"
"<?php
`$P = '10.213';
`$IpHostArr = [`n`n$DnsDataTable`n];
?>" | Out-File -Encoding ASCII -FilePath IpHostLookups.php
Get-Content IpHostLookups.php

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