This seems like it should be a trivial thing.
I am using Powershell v5.1 and I am trying to build a UNC path from 2 strings that represent a server and a share. Given that $Server hold "Distribution" and $Share holds "Publish"...
$Path = "\\" + $Server + "\" + $Share
The output I am getting for $Path is..
\\Distribution Publish\
I tried changing it to...
$Path = "//" + $Server + "/" + $Share
...as a test thinking the special character "\" was causing a problem, but then I still get the odd sequence where there is a space between server and share and the 2nd slash is at the end.
//Distribution Publish/
What am I missing?
As mentioned in the comments, your symptoms cannot be explained if your $Server and $Share variables truly contain just Distribution and Publish, respectively, with no hidden control characters.
Here's a contrived example of variable values that do produce your symptom:
> $Server = 'Distribution', 'Publish'; $Share = "`r"; "\\" + $Server + "\" + $Share
\\Distribution Publish\
As James C. points out, a more concise alternative for building the string is: "\\$Server\$Share".
As TheIncorrigible1 points out, it is better to build paths using Join-Path.
'Distribution', 'Publish' is an array of strings, whose elements PowerShell concatenates with a space (by default) when converting it to a string, which in this case results in Distribution Publish.
"`r" creates control character CR (0xD), which, when printing to the console, resets the cursor position to the first column and prints the remainder of the string there (which in this case is empty).
Note, however, that the CR is still a part of the string, albeit an invisible one.
If you want an easy way to inspect a given string for hidden control characters, see this answer of mine.
Update:
The OP reports that it turned out to be how the $Server and $Share variables were bound via parameters, through mistaken use of (C#) method-invocation syntax:
# Correct invocation: $Server binds to 1st parameter, $Share to 2nd.
./script $Server $Share
# INCORRECT: Binds *both* values to the *first* parameter, as an *array*
# and assigns nothing to the second.
# In PowerShell, "," constructs an array.
./script($Server, $Share)
The tricky thing is that ./script($Server, $Share) happens to be valid PowerShell syntax too, only with different semantics: $Server, $Share constructs a 2-element array whose elements are the values of $Server and $Share, respectively.
To avoid this pitfall, PowerShell offers strict-mode setting Set-StrictMode -Version 2, which reports an error when method-style invocation is attempted. Note, however, that this setting invariably enables other checks as well, notably causing an error when referencing non-existent properties - see Get-Help Set-StrictMode.
Avoid string addition like you're doing when working with paths; there are cmdlets that handle that.
$Server = '\\This.server.name'
$File = 'something.exe'
$UNC = Join-Path $Server $File
Additionally, do string validation if you're running into weird errors.
If (!$Server) { "Stuff"; Return } # Checks empty string
If (!$File) { "Stuff"; Return }
If (!(Test-Path $UNC)) { "Stuff"; Return } # error checking for the file
Related
I'm trying to find an efficient way to read the value of a string variable in a PowerShell .ps1 file and then update the same variable/value in another .ps1 file. In my specific case, I would update a variable for the version # on script one and then I would want to run a script to update it on multiple other .ps1 files. For example:
1_script.ps1 - Script I want to read variable from
$global:scriptVersion = "v1.1"
2_script.ps1 - script I would want to update variable on (Should update to v1.1)
$global:scriptVersion = "v1.0"
I would want to update 2_script.ps1 to set the variable to "v1.1" as read from 1_script.ps1. My current method is using get-content with a regex to find a line starting with my variable, then doing a bunch of replaces to get the portion of the string I want. This does work, but it seems like there is probably a better way I am missing or didn't get working correctly in my tests.
My Modified Regex Solution Based on Answer by #mklement0 :
I slightly modified #mklement0 's solution because dot-sourcing the first script was causing it to run
$file1 = ".\1_script.ps1"
$file2 = ".\2_script.ps1"
$fileversion = (Get-Content $file1 | Where-Object {$_ -match '(?m)(?<=^\s*\$global:scriptVersion\s*=\s*")[^"]+'}).Split("=")[1].Trim().Replace('"','')
(Get-Content -Raw $file2) -replace '(?m)(?<=^\s*\$global:scriptVersion\s*=\s*")[^"]+',$fileversion | Set-Content $file2 -NoNewLine
Generally, the most robust way to parse PowerShell code is to use the language parser. However, reconstructing source code, with modifications after parsing, may situationally be hampered by the parser not reporting the details of intra-line whitespace - see this answer for an example and a discussion.[1]
Pragmatically speaking, using a regex-based -replace solution is probably good enough in your simple case (note that the value to update is assumed to be enclosed in "..." - but matching could be made more flexible to support '...' quoting too):
# Dot-source the first script in order to obtain the new value.
# Note: This invariably executes *all* top-level code in the script.
. .\1_script.ps1
# Outputs to the display.
# Append
# | Set-Content -Encoding utf8 2_script.ps1
# to save back to the input file.
(Get-Content -Raw 2_script.ps1) -replace '(?m)(?<=^\s*\$global:scriptVersion\s*=\s*")[^"]+', $global:scriptVersion
For an explanation of the regex and the ability to experiment with it, see this regex101.com page.
[1] Syntactic elements are reported in terms of line and column position, and columns are character-based, meaning that spaces and tabs are treated the same, so that a difference of, say, 3 character positions can represent 3 spaces, 3 tabs, or any mix of it - the parser won't tell you. However, if your approach allows keeping the source code as a whole while only removing and splicing in certain elements, that won't be a problem, as shown in iRon's helpful answer.
To compliment the helpful answer from #mklement0. In case your do go for the PowerShell abstract syntax tree (AST) class, you might use the Extent.StartOffset/Extent.EndOffset properties to reconstruct your script:
Using NameSpace System.Management.Automation.Language
$global:scriptVersion = 'v1.1' # . .\Script1.ps1
$Script2 = { # = Get-Content -Raw .\Script2.ps1
[CmdletBinding()]param()
begin {
$global:scriptVersion = "v1.0"
}
process {
$_
}
end {}
}.ToString()
$Ast = [Parser]::ParseInput($Script2, [ref]$null, [ref]$null)
$Extent = $Ast.Find(
{
$args[0] -is [AssignmentStatementAst] -and
$args[0].Left.VariablePath.UserPath -eq 'global:scriptVersion' -and
$args[0].Operator -eq 'Equals'
}, $true
).Right.Extent
-Join (
$Script2.SubString(0, $Extent.StartOffset),
$global:scriptVersion,
$Script2.SubString($Extent.EndOffset)
) # |Set-Content .\Script2.ps1
The script below finds folders older than 30 days. I just want to add a simple IF statement to say "There are not folders older than 30 days" if there are not any. But I am not sure how to do that
Thank you
$Test = Get-ChildItem "\\Server\XFER\Cory" -Directory |
Sort LastWriteTime -Descending |
Where-Object {($_.LastWriteTime -lt (Get-Date).AddDays(-30))} |
Select-Object Name, LastWriteTime
Your question boils down to this:
In PowerShell, how can I determine if a command or expression produced any output?
In almost all cases, the following is sufficient, as Ash suggests:
$Test = ... # ... represents any command or expression
if ($null -eq $Test) { 'no output' }
If you know that the command or expression - when it does produce output - only ever emits non-numeric and non-Boolean objects, you can simplify to the following, as Santiago Squarzon suggests, relying on PowerShell's implicit to-Boolean coercion logic, summarized in the bottom section of this answer:
$Test = ... # ... represents any command or expression
if (-not $Test) { 'no output' }
If you're dealing with an (unusual) command that outputs a collection (array) as a single object (as opposed to enumerating the collection and outputting each element separately, which is the normal pipeline behavior) and you want to treat an empty collection object as lack of output too:
$Test = ... # ... represents any command or expression
# Caveat: Due to a bug, only works robustly with
# Set-StrictMode turned off (the default)
# or Set-StrictMode -Version 1 (not higher).
if ($Test.Count -eq 0) { 'no output' }
Note that this works even with $null output and a scalar output object (a single, non-collection object). In the interest of unified treatment of scalars and collections (arrays), PowerShell adds a .Count property even to scalars that themselves do not have it, so that scalars can be treated as if they were a single-element collection, also with respect to indexing; e.g. (42).Count is 1, and (42)[0] is 42; however, note that $null.Count is 0. Such PowerShell engine-supplied type members are called intrinsic members.
Caveat: Due to a long-standing bug - reported in GitHub issue #2798 and still present as of PowerShell 7.2 - accessing the intrinsic .Count property on objects that don't natively have it causes a statement-terminating error if Set-StrictMode -Version 2 or higher is in effect.
However, the tests above do not allow you to distinguish between no output at all and a (single) $null value, which requires the following approach - though do note that actual $null output is unusual in PowerShell:[1]
$Test = ... # ... represents any command or expression
if ($null -eq $Test -and #($Test).Length -eq 0) { 'no output' }
This obscure test is necessary, because no output in PowerShell is represented by the [System.Management.Automation.Internal.AutomationNull]::Value] singleton, which behaves like $null in expression contexts, but not in enumeration contexts such as in a pipeline, including with #(...), the array-subexpression operator, which returns an empty array for [System.Management.Automation.Internal.AutomationNull]::Value] (element count 0) and a single-element array for $null.
While making the distinction between $null and [System.Management.Automation.Internal.AutomationNull]::Value often isn't necessary, there are definitely cases when it is, given that their enumeration behavior differs. Being able to distinguish via a simple test such as $Test -is [AutomationNull] is the subject of GitHub proposal #13465.
[1] Returning $null from PowerShell commands (cmdlets, scripts, functions) is best avoided; instead, simply omit output commands. However, .NET API methods may still return $null and object properties may contain $null (even [string]-typed ones, and even in PowerShell class definitions - see GitHub issue #7294).
EDIT
I think I now know what the issue is - The copy numbers are not REALLY part of the filename. Therefore, when the array pulls it and then is used to get the match info, the file as it is in the array does not exist, only the file name with no copy number.
I tried writing a rename script but the same issue exists... only the few files I manually renamed (so they don't contain copy numbers) were renamed (successfully) by the script. All others are shown not to exist.
How can I get around this? I really do not want to manually work with 23000+ files. I am drawing a blank..
HELP PLEASE
I am trying to narrow down a folder full of emails (copies) with the same name "SCADA Alert.eml", "SCADA Alert[1].eml"...[23110], based on contents. And delete the emails from the folder that meet specific content criteria.
When I run it I keep getting the error in the subject line above. It only sees the first file and the rest it says do not exist...
The script reads through the folder, creates an array of names (does this correctly).
Then creates an variable, $email, and assigns the content of that file. for each $filename in the array.
(this is where is breaks)
Then is should match the specific string I am looking for to the content of the $email var and return true or false. If true I want it to remove the email, $filename, from the folder.
Thus narrowing down the email I have to review.
Any help here would be greatly appreciated.
This is what I have so far... (Folder is in the root of C:)
$array = Get-ChildItem -name -Path $FolderToRead #| Get-Content | Tee C:\Users\baudet\desktop\TargetFile.txt
Foreach ($FileName in $array){
$FileName # Check File
$email = Get-Content $FolderToRead\$FileName
$email # Check Content
$ContainsString = "False" # Set Var
$ContainsString # Verify Var
$ContainsString = %{$email -match "SYS$,ROC"} # Look for String
$ContainsString # Verify result of match
#if ($ContainsString -eq "True") {
#Remove-Item $FolderToRead\$element
#}
}
Here's a PowerShell-idiomatic solution that also resolves your original problems:
Get-ChildItem -File -LiteralPath $FolderToRead | Where-Object {
(Get-Content -Raw -LiteralPath $_.FullName) -match 'SYS\$,ROC'
} | Remove-Item -WhatIf
Note: The -WhatIf common parameter in the command above previews the operation. Remove -WhatIf once you're sure the operation will do what you want.
Note how the $ character in the RHS regex of the -match operator is \-escaped in order to use it verbatim (rather than as metacharacter $, the end-of-input anchor).
Also, given that $ is also used in PowerShell's string interpolation, it's better to use '...' strings (single-quoted, verbatim strings) to represent regexes, assuming no actual up-front string expansion is needed before the regex engine sees the resulting string - see this answer for more information.
As for what you tried:
The error message stemmed from the fact that Get-Content $FolderToRead\$FileName binds the file-name argument, $FolderToRead\$FileName, implicitly (positionally) to Get-Content's -Path parameter, which expects PowerShell wildcard patterns.
Since your file names literally contain [ and ] characters, they are misinterpreted by the (implied) -Path parameter, which can be avoided by using the -LiteralPath parameter instead (which must be specified explicitly, as a named argument).
%{$email -match "SYS$,ROC"} is unnecessarily wrapped in a ForEach-Object call (% is a built-in alias); while that doesn't do any harm in this case, it adds unnecessary overhead;
$email -match "SYS$,ROC" is enough, though it needs to be corrected to
$email -match 'SYS\$,ROC', as explained above.
[System.IO.Directory]::EnumerateFiles($Folder) |
Where-Object {$true -eq [System.IO.File]::ReadAllText($_, [System.Text.Encoding]::UTF8).Contains('SYS$,ROC') } |
ForEach-Object {
Write-Host "Removing $($_)"
#[System.IO.File]::Delete($_)
}
Your mistakes:
%{$email -match "SYS$,ROC"} - What % is intended to be? This is ForEach-Object alias.
%{$email -match "SYS$,ROC"} - Why use -match? This is much slower than -like or String.Contains()
%{$email -match "SYS$,ROC"} - When using $ inside double quotes, you should escape this using single backtick symbol (I have `$100). Otherwise, everything after $ is variable name: Hello, $username; I's $($weather.ToString()) today!
Write debug output in a right way: use Write-Debug, Write-Verbose, Write-Host, Write-Warning, Write-Error, Write-Information.
Can be better:
Avoid using Get-ChildItem, because Get-ChildItem returns files with attributes (like mtime, atime, ctime, etc). This additional info is additional request per file. When you need only list of files, use native .Net EnumerateFiles from System.IO.Directory. This is significant performace boost on huge amounts of files.
Use RealAllText or ReadAllLines or ReadAllBytes from System.IO.File static class to be more concrete instead of using universal Get-Content.
Use pipelines ;-)
We are copying a long list of files from their different directories into a single location (same server). Once there, I need to rename them.
I was able to move the files until I found out that there are duplicates in the list of file names to move (and rename). It would not allow me to copy the file multiple times into the same destination.
Here is the list of file names after the move:
"10.csv",
"11.csv",
"12.csv",
"13.csv",
"14.csv",
"15.csv",
"16.csv",
"17.csv",
"18.csv",
"19.csv",
"20.csv",
"Invoices_Export(16) - Copy.csv" (this one's name should be "Zebra.csv")
I wrote a couple of foreach loops, but it is not working exactly correctly.
The script moves the files just fine. It is the rename that is not working the way I want. The first file does not rename; the other files rename. However, they leave the moved file in place too.
This script requires a csv that has 3 columns:
Path of the file, including the file name (eg. c:\temp\smefile.txt)
Destination of the file, including the file name (eg. c:\temp\smefile.txt)
New name of the file. Just the name and extention.
# Variables
$Path = (import-csv C:\temp\Test-CSV.csv).Path
$Dest = (import-csv C:\temp\Test-CSV.csv).Destination
$NN = (import-csv C:\temp\Test-CSV.csv).NewName
#Script
foreach ($D in $Dest) {
$i -eq 0
Foreach ($P in $Path) {
Copy-Item $P -destination C:\Temp\TestDestination -force
}
rename-item -path "$D" -newname $NN[$i] -force
$i += 1
}
There were no error per se, just not the outcome that I expected.
Welcome to Stack Overflow!
There are a couple ways to approach the duplicate names situation:
Check if the file exists already in the destination with Test-Path. If it does, start a while loop that appends a number to the end of the name and check if that exists. Increment the number you append after each check with Test-Path. Keep looping until Test-Path comes back $false and then break out of the loop.
Write an error message and skip that row in the CSV.
I'm going to show a refactored version of your script with approach #2 above:
$csv = Import-Csv 'C:\temp\Test-CSV.csv'
foreach ($row in $csv)
{
$fullDestinationPath = Join-Path -Path $row.Destination -ChildPath $row.NewName
if (Test-Path $fullDestinationPath)
{
Write-Error ("The path '$fullDestinationPath' already exists. " +
"Skipping row for $($row.Path).")
continue
}
# You may also want to check if $row.Path exists before attempting to copy it
Copy-Item -Path $row.Path -Destination $fullDestinationPath
}
Now that your question is answered, here are some thoughts for improving your code:
Avoid using acronyms and abbreviations in identifiers (variable names, function names, etc.) when possible. Remember that code is written for humans and someone else has to be able to understand your code; make everything as obvious as possible. Someone else will have to read your code eventually, even if it's Future-You™!
Don't Repeat Yourself (called the "DRY" principle). As Lee_daily mentioned in the comments, you don't need to import the CSV file three times. Import it once into a variable and then use the variable to access the properties.
Try to be consistent. PowerShell is case-insensitive, but you should pick a style and stick to it (i.e. ForEach or foreach, Rename-Item or rename-item, etc.). I would recommend PascalCase as PowerShell cmdlets are all in PascalCase.
Wrap literal paths in single quotes (or double quotes if you need string interpolation). Paths can have spaces in them and without quotes, PowerShell interprets a space as you are passing another argument.
$i -eq 0 is not an assignment statement, it is a boolean expression. When you run $i -eq 0, PowerShell will return $true or $false because you are asking it if the value stored in $i is 0. To assign the value 0 to $i, you need to write it like this: $i = 0.
There's nothing wrong with $i += 1, but it could be shortened to $i++, if you want to.
When you can, try to check for common issues that may come up with your code. Always think about what can go wrong. "If I copy a file, what can go wrong? Does the source file or folder exist? Is the name pulled from the CSV a valid path name or does it contain characters that are invalid in a path (like :)?" This is called defensive programming and it will save you so so many headaches. As with anything in life, be careful not to go overboard. Only check for likely scenarios; rare edge-cases should just raise errors.
Write some decent logs so you can see what happened at runtime. PowerShell provides a pair of great cmdlets called Start-Transcript and Stop-Transcript. These cmdlets log all the output that was sent to the PowerShell console window, in addition to some system information like the version of PowerShell installed on the machine. Very handy!
I have the following portion of code:
$fileList | foreach {
Write-Host ". . . adding $_ to script"
$myCreateScript += Get-Content "$ScriptRoot\$_" | Out-String }
That produces the following toward the end of execution:
ItemNotFound,Microsoft.PowerShell.Commands.GetContentCommand
System.Exception: An object at the specified path E:\Scripts\users[[FILE_NAME_LOWER]]_administrator.sql does not exist, or has been filtered by the -Include or -Exclude parameter.
[[FILE_NAME_LOWER]]_administrator.sql is the name of the file, and it does exist in the specified directory. If this is a problem with the fact that the filename contains brackets ([]), I need to know how to resolve it within the foreach block, as I cannot easily change the filenames (they are used elsewhere in code that is in source control) and because of prior code in the script, need to be preserved in $fileList. I suspect the brackets are the issue, because $fileList has over 200 rows, and $myCreateScript gets populated with the correct data up to this point.
You need to use the -LiteralPath parameter of Get-Content:
$myCreateScript += Get-Content -LiteralPath "$ScriptRoot\$_" | Out-String }
Otherwise, [[FILE_NAME_LOWER]] will be interpreted as a wildcard character set which tells PowerShell to match any of the characters enclosed by the two square brackets on each end.