First time trying to use powershell, so I accept that this might be beyond a beginners level.
Objective: Create a CSV from data collected by snmpget.exe (syntax "snmpget.exe -IPAddress -OID"). CSV should be organized by 3 columns that represent 3 different pieces of data collected by snmpget.exe (the 3 OIDs) and rows by IP addresses.
So I've got my list of IPs and I've got my OIDs. I need to run a foreach IP against all 3 OID values in the executable.
$AddressList=#("192.168.0.1","192.168.0.2","192.168.0.3")
$OID1 = ForEach ($Address in AddressList) {snmpget.exe -r:"$Address" -o:1}
$OID2 = ForEach ($Address in AddressList) {snmpget.exe -r:"$Address" -o:2}
$OID3 = ForEach ($Address in AddressList) {snmpget.exe -r:"$Address" -o:3}
My first issue was attempting to export just $OID1.
$OID1 | Export-CSV
Doesn't exactly work because the only string property is length, so I don't actually get the value I want. I then tried Out-File. That works, but I'm not sure how I combine $OID1, $OID2, and $OID3 into a single CSV file with headers.
I mean, if you just want to know how to nest loops, you can do something like this:
$AddressList = "192.168.0.1","192.168.0.2","192.168.0.3";
$OIDList = '1','2','3';
$AddressList | ForEach-Object ($Address in $AddressList) {
$Address = $_;
$OIDList | ForEach-Object {
snmpget.exe -r:"$Address" -o:"$_"
}
} | Export-Csv -NoTypeInformation -Path C:\Export.csv
However, that's going to be super useless since snmpget.exe is not outputting any objects that Export-Csv is looking for. I expect Export-Csv to complain that it doesn't have a header. You could just write out a text file with Set-Content -Path C:\Export.txt or Out-File -FilePath C:\Export.txt instead of Export-Csv, but that's just dumping the output to a text file.
I don't have any SNMP enabled devices on my network, so I have no idea what the output from that snmpget.exe command looks like. Your question is mostly unanswerable without knowing the output of snmpget.exe.
You may want to try the Get-SNMP command from this module or something similar from one of the other SNMP modules in the Gallery. That will output objects instead of plain strings, which will be easier to manipulate.
Related
I have a Commands.csv file like:
| Command |
| -----------------------------------------------|
|(Get-FileHash C:\Users\UserA\Desktop\File1).Hash|
|(Get-FileHash C:\Users\UserA\Desktop\File2).Hash|
|(Get-FileHash C:\Users\UserA\Desktop\File3).Hash|
Header name is "Command"
My idea is to:
Use ForEach ($line in Get-Content C:\Users\UserA\Desktop\Commands.csv ) {echo $line}
Execute $line one by one via powershell.exe, then output a result to a new .csv file - "result.csv"
Can you give me some directions and suggestions to implement this idea? Thanks!
Important:
Only use the technique below with input files you either fully control or implicitly trust to not contain malicious commands.
To execute arbitrary PowerShell statements stored in strings, you can use Invoke-Expression, but note that it should typically be avoided, as there are usually better alternatives - see this answer.
There are advanced techniques that let you analyze the statements before executing them and/or let you use a separate runspace with a restrictive language mode that limits what kinds of statements are allowed to execute, but that is beyond the scope of this answer.
Given that your input file is a .csv file with a Commands column, import it with Import-Csv and access the .Commands property on the resulting objects.
Use Get-Content only if your input file is a plain-text file without a header row, in which case the extension should really be .txt. (If it has a header row but there's only one column, you could get away with Get-Content Commands.csv | Select-Object -Skip 1 | ...). If that is the case, use $_ instead of $_.Commands below.
To also use the CSV format for the output file, all commands must produce objects of the same type or at least with the same set of properties. The sample commands in your question output strings (the value of the .Hash property), which cannot meaningfully be passed to Export-Csv directly, so a [pscustomobject] wrapper with a Result property is used, which will result in a CSV file with a single column named Result.
Import-Csv Commands.csv |
ForEach-Object {
[pscustomobject] #{
# !! SEE CAVEAT AT THE TOP.
Result = Invoke-Expression $_.Commands
}
} |
Export-Csv -NoTypeInformation Results.csv
I'm far away from being an expert in PowerShell, so I'll be my best to explain here.
I was able to add a column, but now I want to add stuff in a column (already there) using a separate script.
For example, the following CSV file:
WhenToBuyThings,ThingsToBuy
BuyNow ,Bed
BuyNow ,Desk
BuyNow ,Computer
BuyNow ,Food
BuyLater ,
BuyLater ,
BuyLater ,
I have the array:
$BuyStuffLater = "Books","Toys","ShinnyStuff"
So the end result of the file should look like this
BuyNow ,Bed
BuyNow ,Desk
BuyNow ,Computer
BuyNow ,Food
BuyLater ,Books
BuyLater ,Toys
BuyLater ,ShinnyStuff
Any help with how to do this in code would be much appreciated. Also, we can't use delimiter ",". Because in the real script some values will have commas.
I got it after a few hours of fiddling...
$myArray = "Books","Toys","ShinnyStuff"
$i = 0
Import-Csv "C:\Temp\test.csv" |
ForEach-Object {if($_.WhenToBuyThings -eq "BuyLater"){$_.ThingsToBuy = $myArray[$i];$i++}return $_} |
Export-Csv C:\Temp\testtemp.csv -NoTypeInformation
All is well now...
I am new to powershell, too. Here's what I found. This searches and returns all lines that fit. I'm not sure it can pipe.
$BuyStuffLater = "Books","Toys","ShinnyStuff"
$x = 0
Get-Content -Path .\mydata.txt | select-string -pattern "BuyLater" #searches and displays
# Im not sure about this piping. (| foreach {$_ + $BuyStuffLater[$x];$x++} | Set-Content .\outputfile.csv)
This filter will work, though I still have to work on the piping. The other answer might be better.
I don't see a point to iterating through each object to see if it is a WhenToBuyThings is "BuyLater". If anything what you are doing could be harmful if you run multiple passes adding to the list. It could remove previous things you wanted to by. If "Kidney Dialysis Machine" was listed as a "BuyLater" under WhenToBuyThings then you would overwrite it with dire consequences.
What we can do is build two lists and merge into new csv file. First list is your original file minus any entry where a "BuyLater" has a blank ThingsToBuy. The second list is an object array built from your $BuyStuffLater. Add these lists together and export.
Also there is zero need to worry about using a comma delimiter when using Export-CSV. The data is quoted so commas in data do not affect the data structure. If this was still a concern you could use -Delimiter ";". I noticed in your answer that you did not attempt to account for commas either (not that it matters based on what I just said).
$path = "C:\Temp\test.csv"
$ListOfItemsToBuy = "Books","Toys","ShinnyStuff: Big, ShinyStuff"
$BuyStuffLater = $ListOfItemsToBuy | ForEach-Object{
[pscustomobject]#{
WhenToBuyThings = "BuyLater"
ThingsToBuy = $_
}
}
$CurrentList = Import-Csv $path | Where-Object{$_.WhenToBuyThings -ne "BuyLater" -and ![string]::IsNullOrWhiteSpace($_.ThingsToBuy)}
$CurrentList + $BuyStuffLater | Export-Csv $path -NoTypeInformation
Since you have 3.0 we can use [pscustomobject]#{} to build the new object very easily. Combine both arrays simply by adding them together and export back to the original file.
You should notice I used slightly different input data. One includes a comma. I did that so you can see what the output file looks like.
"BuyLater","Books"
"BuyLater","Toys"
"BuyLater","ShinnyStuff: Big, ShinyStuff"
I have a .csv file and I want to import it into powershell then iterate through the file changing certain values. I then want the output to append to the original .csv file, so that the values have been updated.
My issue is that the .csv file has headers which aren't unique, and can't be changed as then it won't work in another program. Originally I defined my own headers in the powershell to get around this but then the output file has these new headers when it needs to have the old ones.
I have also tried ConvertFrom-Csv which means I can no longer access the columns I need to, so lots of runtime errors.
What would be ideal is to be able to use the defined column headers and then convert back to the original column headers. My current code is below:
$csvfile = Import-Csv C:\test.csv| Where-Object {$_.'3' -eq $classID} | ConvertFrom-Csv
foreach($record in $csvfile){
*do something*}
$csvfile | Export-Csv -path C:\test.csv -NoTypeInformation -Append
I've searched the web now for some hours and tried everything I've come across, to no avail.
Thanks in advance.
This is a somewhat hackish implementation but should work.
Remove all the headers as a single line and save it somewhere
Parse the new result-set (with the headers removed)
Add the line at the top when you are finished
A CSV is a comma delimited file, you don't have to treat it like structured data. Feel free to splice and dice as you want.
Since you know beforehand how many columns are in the input CSV file, you can import without the header and process internally. Example:
$columns = 78
Import-Csv "inputfile.csv" -Header (0..$($columns - 1)) | Select-Object -Skip 1 | ForEach-Object {
$row = $_
$outputObject = New-Object PSObject
0..$($columns- 1) | ForEach-Object {
$outputObject | Add-Member NoteProperty "Col$_" $row.$_
}
$outputObject
} | Export-Csv "outputfile.csv" -NoTypeInformation
This example generates new PSObjects and then outputs a new CSV file with generic column names (Col0, Col1, etc.).
Question
How do I reformat an unknown CSV column name according to a formula or subroutine (e.g. rename column " Arbitrary Column Name " to "Arbitrary Column Name" by running a trim or regex or something) while maintaining data?
Goal
I'm trying to more or less sanitize columns (the names) in a hand-produced (or at least hand-edited) csv file that needs to be processed by an existing PowerShell script. In this specific case, the columns have spaces that would be removed by a call to [String]::Trim(), or which could be ignored with an appropriate regex, but I can't figure a way to call or use those techniques when importing or processing a CSV.
Short Background
Most files and columns have historically been entered into the CSV properly, but recently a few columns were being dropped during processing; I determined it was because the files contained a space (e.g., Select-Object was being told to get "RFC", but Import-CSV retrieved "RFC ", so no matchy-matchy). Telling the customer to enter it correctly by hand (though preferred and much simpler) is not an option in this case.
Options considered
I could manually process the text of the file, but that is a messy and error prone way to re-invent the wheel. I wonder if there's a syntax with Select-Object that would allow a softer match for column names, but I can't find that info.
The closest I have come conceptually is using a calculated property in the call to Select-Object to rename the column, but I can only find ways to rename a known column to another known column. So, this would require enumerating the columns and matching them exactly (preferred) or a softer match (like comparing after trimming or matching via regex as a fallback) with expected column names, then creating a collection of name mappings to use in constructing calculated properties from that information to select into a new object.
That seems like it would work, but more it's work than I'd prefer, and I can't help but hope that there's a simpler way I haven't been able to find via Google. Maybe I should try Bing?
Sample File
Let's say you have a file.csv like this:
" RFC "
"1"
"2"
"3"
Code
Now try to run the following:
$CSV = Get-Content file.csv -First 2 | ConvertFrom-Csv
$FixedHeaders = $CSV.PSObject.Properties.Name.Trim(' ')
Import-Csv file.csv -Header $FixedHeaders |
Select-Object -Skip 1 -Property RFC
Output
You will get this output:
RFC
---
1
2
3
Explanation
First we use Get-Content with parameter -First 2 to get the first two lines. Piping to ConvertFrom-Csv will allow us to access the headers with PSObject.Properties.Name. Use Import-Csv with the -Header parameter to use the trimmed headers. Pipe to Select-Object and use -Skip 1 to skip the original headers.
I'm not sure about comparisons in terms of efficiency, but I think this is a little more hardened, and imports the CSV only once. You might be able to use #lahell's approach and Get-Content -raw, but this was done and it works, so I'm gonna leave it to the community to determine which is better...
#import the CSV
$rawCSV = Import-Csv $Path
#get actual header names and map to their reformatted versions
$CSVColumns = #{}
$rawCSV |
Get-Member |
Where-Object {$_.MemberType -eq "NoteProperty"} |
Select-Object -ExpandProperty Name |
Foreach-Object {
#add a mapping to the original from a trimmed and whitespace-reduced version of the original
$CSVColumns.Add(($_.Trim() -replace '(\s)\s+', '$1'), "$_")
}
#Create the array of names and calculated properties to pass to Select-Object
$SelectColumns = #()
$CSVColumns.GetEnumerator() |
Foreach-Object {
$SelectColumns += {
if ($CSVColumns.values -contains $_.key) {$_.key}
else { #{Name = $_.key; Expression = $CSVColumns[$_.key]} }
}
}
$FormattedCSV = $rawCSV |
Select-Object $SelectColumns
This was hand-copied to a computer where I don't have the rights to run it, so there might be an error - I tried to copy it correctly
You can use gocsv https://github.com/DataFoxCo/gocsv to see the headers of the csv, you can then rename the headers, behead the file, swap columns, join, merge, any number of transformations you want
I have a pipe-delimited text file with a header row. (I said CSV in the question to make it a a bit more immediately understandable ... I imagine most solutions would be applicable to either format.)
The file looks like this:
COLUMN1|COLUMN2|COLUMN3|COLUMN4|...|
Field1|Field2|Field3|Field4|...|
...
I need to obscure the data in (for example) columns 3 and 9, without affecting any of the other entries in the file.
I want to do this using a hashing algorithm like SHA1 or MD5, so that the same strings will resove to the same hash values anywhere they are encountered.
EDIT - Why I want to do this
I need to send some data to a third party, and certain columns contain sensitive information (e.g. customer names). I need the file to be complete, and where a string is replaced, I need it to be done in the same way every time it is encountered (so that any mapping or grouping remains). It does not need military encryption, just to be difficult to reverse. As I need to to this intermittently, a scripted solution would be ideal.
/EDIT
What is the easiest way to achieve this using a command line tool or script?
By preference, I would like a batch script or PowerShell script, since that does not require any additional software to achieve...
Try
(Import-Csv .\my.csv -delimiter '|' ) | ForEach-Object{
$_.column3 = $_.column3.gethashcode()
$_.column4 = $_.column4.gethashcode()
$_
} | Export-Csv .\myobfuscated.csv -NoTypeInformation -delimiter '|'
$md5 = new-object -TypeName Security.Cryptography.MD5CryptoServiceProvider
$utf8 = new-object -TypeName Text.UTF8Encoding
import-csv original.csv -delimiter '|' |
foreach {
$_.Column3 = [BitConverter]::ToString($md5.ComputeHash($utf8.GetBytes($_.Column3)))
$_.Column9 = [BitConverter]::ToString($md5.ComputeHash($utf8.GetBytes($_.Column9)))
$_
} |
export-csv encrypted.csv -delimiter '|' -noTypeInformation