I'm trying to replace some specific parts of a selected string but am only returning the length property. Here's my code:
Get-ChildItem "StartPath/Something/Files" -Recurse -File | Select "FullName | Foreach {$_.FullName -replace "StartPath",""} | Export-Csv "ResultPath.csv"
If I omit the foreach bit, this works in that it spits out the full path. I'd like to trim the full path as I'm iterating over tons of files. I'm trying to replace a bit of the path in the beginning of the string but my code above just spits out a CSV file with just string lengths.
Looks like:
"123"
"12"
"52"
and so forth.
The intended result would be a csv file with instead of:
StartPath/Something/Files1
StartPath/Something/Files2
I'd have
Something/Files1
Something/Files2
I've tried a number of things and can't seem to figure it out. Any help is appreciated.
If you pass a string to select / Select-Object (to its positionally implied -Property parameter), it must be a property name.[1]
If you want to perform open-ended operations and/or produce open-ended output for each input object, you must use the ForEach-Object cmdlet:
Get-ChildItem "StartPath/Something/Files" -Recurse -File |
ForEach-Object {
[pscustomobject] #{ FullName = $_.FullName -replace 'StartPath' }
} |
Export-Csv "ResultPath.csv"
Note the use of a [pscustomobject] wrapper that defines a FullName property, so that Export-Csv creates a CSV with that property as its (only) column.
If you pipe [string] instances directly to Export-Csv, their properties are serialized to the output file - and a [string]'s only (public) property is its length (.Length), which is what you saw.
[1] There's also a way to create properties dynamically, using so-called calculated properties, which are defined via hash tables.
Related
I have a script that periodically generates a list of all files in a directory, and then writes a text file of the results to a different directory.
I'd like to change this so it checks the newest text file in the output directory, and only makes a new one if there's differences. It seemed simple enough.
Here's what I tried:
First I get the most recent file in the directory, grab the hash, and write my variable values to the console:
$lastFile = gci C:\ReportOutputDir | sort LastWriteTime | select -last 1 | Select-Object -ExpandProperty FullName
$oldHash = Get-FileHash $lastFile | Select-Object Hash
Write-Host 'lastFile = '$lastFile
Write-Host 'oldHash = '$oldHash
Output:
lastFile = C:\ReportOutputDir\test1.txt
oldHash = #{Hash=E7787C54F5BAE236100A24A6F453A5FDF6E6C7333B60ED8624610EAFADF45521}
Then I do the exact same gci on the FileList dir, and create a new file (new_test.txt), then grab the hash of this file:
gci -Path C:\FileLists -File -Recurse -Name -Depth 2 | Sort-Object | out-file C:\ReportOutputDir\new_test.txt
$newFile = gci C:\ReportOutputDir | sort LastWriteTime | select -last 1 | Select-Object -ExpandProperty FullName
$newHash = Get-FileHash $newFile | Select-Object Hash
Write-Host 'newFile = '$newFile
Write-Host 'newHash = '$newHash
Output:
newFile = C:\ReportOutputDir\new_test.txt
newHash = #{Hash=E7787C54F5BAE236100A24A6F453A5FDF6E6C7333B60ED8624610EAFADF45521}
Finally, I attempt my -eq operator where I'd usually simply remove the newFile if it's equal. For now, I'm just doing a simple :
if ($newHash -eq $oldHash){
'files are equal'
}
else {'files are not equal'}
And somehow, I'm getting
files are not equal
What gives? Also, for the record I was originally trying to save the gci output to a variable and comparing the contents of the last file to the gci output, but was also having trouble with the -eq operator. Fairly new to powershell stuff so I'm sure I'm doing something wrong here.
Select-Object Hash creates an object with a .Hash property and it is that property that contains the hash string.
The object returned is of type [pscustomobject], and two instances of this type never compare as equal - even if all their property names and values are equal:
The reason is that reference equality is tested, because [pscustomobject] is a .NET reference type that doesn't define custom equality-testing logic.
Testing reference equality means that only two references to the very same instance compare as equal.
A quick example:
PS> [pscustomobject] #{ foo = 1 } -eq [pscustomobject] #{ foo = 1 }
False # !! Two distinct instances aren't equal, no matter what they contain.
You have two options:
Compare the .Hash property values, not the objects as a whole:
if ($newHash.Hash -eq $oldHash.Hash) { # ...
If you don't need a [pscustomobject] wrapper for the hash strings, use Select-Object's -ExpandProperty parameter instead of the (possibly positionally implied) -Property parameter:
Select-Object -ExpandProperty Hash
As for why the Write-Host output matched:
When you force objects to be converted to string representations - essentially, Write-Host calls .ToString() on its arguments - the string representations of distinct [pscustomobject] instances that have the same properties and values will be the same:
PS> "$([pscustomobject] #{ foo = 1 })" -eq "$([pscustomobject] #{ foo = 1 })"
True # Same as: '#{foo=1}' -eq '#{foo=1}'
However, you should not rely on these hashtable-like string representations to determine equality of [pscustomobject]s as a whole, because of the inherent limitations of these representations, which can easily yield false positives.
This answer shows how to compare [pscustomobject] instances as a whole, by comparing all of their property values, by passing all property names to Compare-Object -Property - but note that this assumes that all property values are either strings or instances of .NET value types or corresponding properties must again either reference the very same instance of a .NET reference type or be of a type that implements custom equality-comparison logic.
How to find the count of unique numbers in a CSV file? When I use the following command in PowerShell ISE
1,2,3,4,2 | Sort-Object | Get-Unique
I can get the unique numbers but I'm not able to get this to work with CSV files. If for example I use
$A = Import-Csv C:\test.csv | Sort-Object | Get-Unique
$A.Count
it returns 0. I would like to count unique numbers for all the files in a given folder.
My data looks similar to this:
Col1,Col2,Col3,Col4
5,,7,4
0,,9,
3,,5,4
And the result should be 6 unique values (preferably written inside the same CSV file).
Or would it be easier to do it with Notepad++? So far I have found examples only on how to count the unique rows.
You can try the following (PSv3+):
PS> (Import-CSV C:\test.csv |
ForEach-Object { $_.psobject.properties.value -ne '' } |
Sort-Object -Unique).Count
6
The key is to extract all property (column) values from each input object (CSV row), which is what $_.psobject.properties.value does;
-ne '' filters out empty values.
Note that, given that Sort-Object has a -Unique switch, you don't need Get-Unique (you need Get-Unique only if your input already is sorted).
That said, if your CSV file is structured as simply as yours, you can speed up processing by reading it as a text file (PSv2+):
PS> (Get-Content C:\test.csv | Select-Object -Skip 1 |
ForEach-Object { $_ -split ',' -ne '' } |
Sort-Object -Unique).Count
6
Get-Content reads the CSV file as a line of strings.
Select-Object -Skip 1 skips the header line.
$_ -split ',' -ne '' splits each line into values by commas and weeds out empty values.
As for what you tried:
Import-CSV C:\test.csv | Sort-Object | Get-Unique:
Fundamentally, Sort-Object emits the input objects as a whole (just in sorted order), it doesn't extract property values, yet that is what you need.
Because no -Property argument is passed to Sort-Object to base the sorting on, it compares the custom objects that Import-Csv emits as a whole, by their .ToString() values, which happen to be empty[1]
, so they all compare the same, and in effect no sorting happens.
Similarly, Get-Unique also determines uniqueness by .ToString() here, so that, again, all objects are considered the same and only the very first one is output.
[1] This may be surprising, given that using a custom object in an expandable string does yield a value: compare $obj = [pscustomobject] #{ foo ='bar' }; $obj.ToString(); '---'; "$obj". This inconsistency is discussed in this GitHub issue.
I have a problem I am hoping someone could help with....
I have a powershell script containing the lines shown below:
$output = Get-ChildItem -path $target -recurse | Select-String -pattern hello | group path | select name
Write-Output "Output from the string match is $output"
The error I am getting:
Output from the string match Microsoft.Powershell.Commands.GroupInfo Microsoft.Powershell.Commands.GroupInfo
When I run this command on it's own (ie not within a script) it works perfectly and returns the two files in that location that contains the word "hello".
It appears that it knows there are two things it has found because it prints the "Microsoft.Powershell.Commands.GroupInfo" text twice (as shown above in the error). But why is it printing this and not the path to the files as it should do?
There must be something obvious I am overlooking but I dont know what.
Your help is much appreciated, thanks
The reason you're seeing this is because $output is an array of Selected.Microsoft.PowerShell.Commands.GroupInfo objects -- the objects returned by Group-Object when passed to Select-Object (without Select-Object they would just be Microsoft.PowerShell.Commands.GroupInfo objects instead). You can confirm the type of objects in $ouput by running:
$output | Get-Member
Check the TypeName that is displayed at the top of the output.
When you run these commands interactively in the console, you are seeing the paths because PowerShell knows how to display GroupInfo objects in the console so that they are human-readable. Note that when you just call $output in the console, you see a "Name" header underlined with dash characters -- this is PowerShell interpreting the GroupInfo object you gave it and displaying the Name property for you in the console.
The problem occurs when you try to output the $output array inside a string. Then PowerShell is not able to use its more advanced formatting logic and instead merely tries to convert the object to a string to insert into your string. When it does that, it doesn't have enough logic to know that what you really want to appear in your string is the Name property of these GroupInfo objects, so instead if just prints out a string with the type name of each of the objects in the $output array. So that's why you see the type name twice.
The simple solution to this problem is the -ExpandProperty parameter for Select-Object. This does what it says -- it expands the property you asked for with Select-Object and returns just that property, not the parent object. So the Name property of a GroupInfo object is a string. If you call Select-Object Name, you get a GroupInfo object with the Name property. If you call Select-Object -ExpandProperty Name, you get just the Name property as a String object. Which is what I expect that you want in this case.
So try this instead:
$output = Get-ChildItem -path $target -recurse | Select-String -pattern hello | group path | select -ExpandProperty name
A foreach would be appropriate here I believe. Try this:
$output = Get-ChildItem -path $target -recurse | where {$_.name -like "*hello*"} | select name
foreach ($file in $output) {
write-host $file.name
}
Or this:
$output = Get-ChildItem -path $target -recurse | select-string -pattern "hello" | select name
foreach ($file in $output) {
write-output $file.name
}
Since, i am a beginner, i 've no much hands-on to the powershell programming.Although
i had a script developed to insert data from an array to the csv file as follows:
#Following is the array
$InventoryReport = New-Object -TypeName PSobject -Property #{
ComputerName = "1myComputerName"
DomainName = "2myComputerDomain"
Manufacturer = "3myComputerManufacturer"
}
#Now to export the data to csv, i am using following:
$InventoryReport |Select-Object -Property ComputerName, DomainName, Manufacturer | Export-Csv -Path "c:\abc.csv" -NoTypeInformation -ErrorAction Stop
#This works fine
and the output of above is :
"ComputerName","DomainName","Manufacturer"
"1myComputerName","2myComputerDomain","3myComputerManufacturer"
....
Now, i don't want this , i want the ouput to appear in columnar fashion i.e.
"ComputerName","1myComputerName"
"DomainName","2myComputerDomain"
"Manufacturer","3myComputerManufacturer"
What code changes should be done to achieve this. ?
Either you want CSV, which you already have, or you want a custom txt-file. If you want the latter, try this:
$comp = gwmi win32_computersystem
#"
"ComputerName","$($comp.Name)"
"DomainName","$($comp.Domain)"
"Manufacturer","$($comp.Manufacturer)"
"# | Out-File test.txt
sample of test.txt output below. I've got a non-domain, custom built pc, so don't worry about the values.
"ComputerName","GRAIMER-PC"
"DomainName","WORKGROUP"
"Manufacturer","System manufacturer"
EDIT I suggest you learn what CSV is. Remember that CSV is not a fileformat, it's a formatting-style used in a normal textfile. The .csv extension is just cosmetic to let people know that the textfile uses the csv-style. Check out Wikipedia and Technet
In the CSV file, each object is represented by a comma-separated list
of the property values of the object. The property values are
converted to strings (by using the ToString() method of the object),
so they are generally represented by the name of the property value.
Export-CSV does not export the methods of the object.
The format of an exported file is as follows:
-- The first line of the CSV file contains the string '#TYPE ' followed by the fully qualified name of the object, such as #TYPE
System.Diagnostics.Process. To suppress this line, use the
NoTypeInformation parameter.
-- The next line of the CSV file represents the column headers. It contains a comma-separated list of the names of all the properties of
the first object.
-- Additional lines of the file consist of comma-separated lists of the property values of each object.
You could try something like this:
$InventoryReport | Format-List ComputerName, DomainName, Manufacturer `
| Out-String -Stream `
| ? { $_ -ne '' } `
| % { $_ -replace '\s+:\s+', '","' -replace '(^|$)', '"' }
In a PowerShell script, I have some objects that I pass to the Format-Table CmdLet.
The output of my script looks like this:
Something...
Operation AttributeName AttributeValue
--------- ------------- --------------
Delete Member John Doe
Something else...
Since the meaning of the fields is pretty self-explanatory, I would like to remove the headers, the '---' separators and the blank lines at the beginning and at the end from the output of Format-Table.
I don't think that the CmdLet supports this (or at least if there's a parameter to do this I couldn't find it).
What would the best way to leave only the lines with the actual values from the output of Format-Table?
Try the -HideTableHeaders parameter to Format-Table:
gci | ft -HideTableHeaders
(I'm using PowerShell v2. I don't know if this was in v1.)
Try -ExpandProperty. For example, I use this for sending the clean variable to Out-Gridview -PassThru , otherwise the variable has the header info stored. Note that these aren't great if you want to return more than one property.
An example:
Get-ADUser -filter * | select name -expandproperty name
Alternatively, you could do this:
(Get-ADUser -filter * ).name
The -HideTableHeaders parameter unfortunately still causes the empty lines to be printed (and table headers appearently are still considered for column width). The only way I know that could reliably work here would be to format the output yourself:
| % { '{0,10} {1,20} {2,20}' -f $_.Operation,$_.AttributeName,$_.AttributeValue }
Here is how I solve this. I just pipe the output to Out-String and then pass that output to the .NET Trim function:
(gci | ft -HideTableHeaders | Out-String).Trim()
This will strip out the line breaks before and after the table.
You can also use TrimStart to just take care of the header's line break if you still want the trailing line breaks.
(gci | ft -HideTableHeaders | Out-String).TrimStart()
Another approach is to use ForEach-Object to project individual items to a string and then use the Out-String CmdLet to project the final results to a string or string array:
gci Microsoft.PowerShell.Core\Registry::HKEY_CLASSES_ROOT\CID | foreach { "CID Key {0}" -f $_.Name } | Out-String
#Result: One multi-line string equal to:
#"
CID Key HKEY_CLASSES_ROOT\CID\2a621c8a-7d4b-4d7b-ad60-a957fd70b0d0
CID Key HKEY_CLASSES_ROOT\CID\2ec6f5b2-8cdc-461e-9157-ffa84c11ba7d
CID Key HKEY_CLASSES_ROOT\CID\5da2ceaf-bc35-46e0-aabd-bd826023359b
CID Key HKEY_CLASSES_ROOT\CID\d13ad82e-d4fb-495f-9b78-01d2946e6426
"#
gci Microsoft.PowerShell.Core\Registry::HKEY_CLASSES_ROOT\CID | foreach { "CID Key {0}" -f $_.Name } | Out-String -Stream
#Result: An array of single line strings equal to:
#(
"CID Key HKEY_CLASSES_ROOT\CID\2a621c8a-7d4b-4d7b-ad60-a957fd70b0d0",
"CID Key HKEY_CLASSES_ROOT\CID\2ec6f5b2-8cdc-461e-9157-ffa84c11ba7d",
"CID Key HKEY_CLASSES_ROOT\CID\5da2ceaf-bc35-46e0-aabd-bd826023359b",
"CID Key HKEY_CLASSES_ROOT\CID\d13ad82e-d4fb-495f-9b78-01d2946e6426")
The benefit of this approach is that you can store the result to a variable and it will NOT have any empty lines.
I know it's 2 years late, but these answers helped me to formulate a filter function to output objects and trim the resulting strings. Since I have to format everything into a string in my final solution I went about things a little differently.
Long-hand, my problem is very similar, and looks a bit like this
$verbosepreference="Continue"
write-verbose (ls | ft | out-string) # this generated too many blank lines
Here is my example:
ls | Out-Verbose # out-verbose formats the (pipelined) object(s) and then trims blanks
My Out-Verbose function looks like this:
filter Out-Verbose{
Param([parameter(valuefrompipeline=$true)][PSObject[]]$InputObject,
[scriptblock]$script={write-verbose "$_"})
Begin {
$val=#()
}
Process {
$val += $inputobject
}
End {
$val | ft -autosize -wrap|out-string |%{$_.split("`r`n")} |?{$_.length} |%{$script.Invoke()}
}
}
Note1: This solution will not scale to like millions of objects(it does not handle the pipeline serially)
Note2: You can still add a -noheaddings option.
If you are wondering why I used a scriptblock here, that's to allow overloading like to send to disk-file or other output streams.