Remove "." in file name while retaining file extension - powershell

I am trying to use PS to rename a bunch files within a big share and one of the requirements is to remove a dot from the file name. I have tested a few things with my rather basic skills and of course the most basic of scripts zap the file extension.
I finally came up with something like this:
gci *.xlsx | rename-item -newname {$_.Name.replace(".","") + $_.extension }
But that adds the extension to the end of the filename (while keeping the file extension intact)
I thought I could zap the last four symbols using something like this:
gci *.xlsx | rename-item -newname { $_.basename.substring(0,$_.basename.length-4) + $_.extension }
Overall this seems like an overly complicated operation which could also mess up files without dots (unless I specify xlsx as only 4 symbols to be removed)
Would anyone be able to point me in the right direction to an easier solution? ;-)

You were on the right track with your second attempt: using the .BaseName and .Extension properties of the [System.IO.FileInfo] instances[1] output by Get-ChildItem allows you to modify the base name (the file name without its extension) separately, and then re-append the extension to form the full file name:
Get-ChildItem *.xlsx |
Rename-Item -NewName { ($_.BaseName -replace '\.') + $_.Extension } -WhatIf
Note: The -WhatIf common parameter in the command above previews the operation. Remove -WhatIf once you're sure the operation will do what you want.
The above uses the regex-based -replace operator to remove all . instances from the base name; because . is a regex metacharacter (representing any single character), it must be escaped as \. in order to be used literally.
In this simple case, you could have used the [string] type's .Replace() method as well ($_.BaseName.Replace('.', '')), but -replace offers more features and has fewer surprises - see this answer for more information.
Case in point: Say you wanted to remove only the first . from the base name; -replace allows you to do that as follows (but you couldn't do it with .Replace()):
'foo.bar.baz' -replace '\.(.*)$', '$1' # -> 'foobar.baz'
[1] .BaseName isn't a native property of this type; instead, it is a property that PowerShell decorates instances of the type with, using its ETS (Extended Type System).

Related

Powershell - How to replace dots on files exept the extension

I have a question about the replacement of dots on multiple files, i have the next code:
Dir | Rename-item -NewName{ $_.basename.replace(".","-") + $_.extension }
This code works, but i have folders with dots and the problem is when i run the code, the folders repeat the words after the point like a "file extension":
like this:
How can i resolve this problem, i need just replace the dot on folder name with another word or space or everything i like and the files on the folder just replace before the extension.
thanks!
Unfortunately, the .BaseName ETS (Extended Type System) property that PowerShell adds to System.IO.DirectoryInfo instances, i.e. directories, by - unfortunate - design, unconditionally reports the directory name as-is.
It is only for System.IO.FileInfo instances, i.e. files, that .BaseName strips the extension, i.e., the last .-separated component.[1]
You can work around the problem by calling the System.IO.Path.GetFileNameWithoutExtension .NET method, which does not make this distinction (similarly, the type-native .Extension property doesn't make this distinction either, so it can be used as-is).
Get-ChildItem | Rename-Item -NewName {
[IO.Path]::GetFileNameWithoutExtension($_.Name).Replace('.', '-') + $_.Extension
}
[1] You can verify this as follows:
(Get-TypeData System.IO.DirectoryInfo).Members.BaseName vs.
(Get-TypeData System.IO.FileInfo).Members.BaseName

Replace text in files within a folder PowerShell

I have a folder that contains files like 'goodthing 2007adsdfff.pdf', 'betterthing 2007adfdsw.pdf', and 'bestthing_2007fdsfad.pdf', I want to be able to rename each, eliminating all text including 2007 OR _2007 to the end of the string keeping .pdf and getting this result: 'goodthing.pdf' 'betterthing.pdf' 'bestthing.pdf' I've tried this with the "_2007", but haven't figured out a conditional to also handle the "2007". Any advice on how to accomplish this is greatly appreciated.
Get-ChildItem 'C:Temp\' -Name -Filter *.pdf | foreach { $_.Split("_2017")[0].substring(0)}
Try the following:
Get-ChildItem 'C:\Temp' -Name -Filter *.pdf |
Rename-Item -NewName { $_.Name -replace '[_ ][^.]+' } -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.
The above uses Rename-Item with a delay-bind script block and the -replace operator as follows:
Regex [_ ][^.]+ matches everything from the first space or _ char. (character set [ _]) through to the following literal . char. ([^.]+ matches one or more chars. other than (^) than .) - that is, everything from the first / _ through to the filename extension (excluding the .).
Note: To guard against file names such as _2017.pdf matching (which would result in just .pdf as the new name), use the following regex instead: '(?<=.)[_ ][^.]+'
By not providing a replacement operand to -replace, what is matched is replace with the empty string and therefore effectively removed.
The net effect is that input files named
'goodthing 2007adsdfff.pdf', 'betterthing 2007adfdsw.pdf', 'bestthing_2007fdsfad.pdf'
are renamed to
'goodthing.pdf', 'betterthing.pdf', 'bestthing.pdf'
Without knowing the names of all the potential files, I can offer this solution that is 100%:
PS> $flist = ("goodthing 2007adsdfff.pdf","betterthing 2007adfdsw.pdf","bestthing_2007fdsfad.pdf")
PS> foreach ($f in $flist) {$nicename = ($f -replace "([\w\s]+)2007.*(\.\w+)", '$1$2') -replace "[\s_].","." ;$nicename}
goodthing.pdf
betterthing.pdf
bestthing.pdf
Two challenges:
the underscore is actually part of the \w character class. So the alternative to the above is to complicate the regex or try to assume that there will always be only one '_' before the 2007. Both seemed risky to me.
if there are spaces in filenames, there is no telling if you might encounter more than one. This solution removes only the one right before 2007.
The magic:
The -replace operator enables you to quickly capture text in () and re-use it in variables like $1$2. If you have more complex captures, you just have to figure out the order they are assigned.
Hope this helps.

Appending string to the end of all file names in PowerShell

I have files look like
data.svg
map.svg
aplicationp.svg
...
*.svg
I am trying to add -b string to the end of all files names bu using power shell rename command like
D:\icons> Dir | Rename-Item -NewName {$_.name -replace ".","-b."}
to get these
data-b.svg
map-b.svg
application-b.svg
but this is not changing anything. How can I achieve this?
Powershell's -replace operator is based on regular expressions. And since . is a wildcard in regex, what should be happening is that each character in the file name is being replaced with the resulting string. So test.txt would become -b.-b.-b.-b.-b.-b.-b in your example.
You likely want to use the Replace method of the .NET String type like this instead.
dir | Rename-Item -NewName { $_.Name.Replace('.','-b.') }
If you want to keep using -replace, you need to escape the . in your expression like this.
dir | Rename-Item -NewName { $_.Name -replace '\.','-b.' }
Both of these have a couple edge case problems that you may want to avoid. The first is narrowing the scope of your dir (which is just an alias for Get-ChildItem) to avoid including files or directories you don't actually want to rename. The second is that a simple replace in the file name doesn't account for file names that contain multiple dots. So you may want to ultimately do something like this if you only care about SVG files that may have multiple dots.
Get-ChildItem *.svg -File | Rename-Item -NewName { "$($_.BaseName)-b$($_.Extension)" }
The replace operator uses regex. Therefore your . needs to be escaped, otherwise it just stands for any character. I would generally make sure to be as specific as possible when writing regexes. The following is a possible solution
Get-ChildItem *.svg | Rename-Item -NewName { $_.name -Replace '\.svg$','-c.svg' }
The $ anchors the expression to the end of the string which makes sure it only changes the extension and not any other text inside the file names.

Removing Parts of a File Name based on a Delimiter

I have various file names that are categorized in two different ways. They either just have a code like: "866655" or contain a suffix and prefix "eu_866655_001". My hope is to write to a text file the names of files in the same format. I cannot figure out a successful method for removing the suffix and prefix.
Currently this what I have in my loop in Powershell:
$docs = Get-ChildItem -Path $source | Where-Object {$_.Name -match '.doc*'}
if ($docs.basename -contians 'eu_*')
{
Write-Output ([io.fileinfo]"$doc").basename.split("_")
}
I'm hoping to turn "eu_866655_001" into "866655" by using "_" as the delimiter.
I'm aware that the answer is staring me down but I still can't seem to figure it out.
You could do something like the following. Feel free to tweak the -Filter on the Get-ChildItem command.
$source = 'c:\path\*'
$docs = Get-ChildItem -Path $source -File -Filter "*_*_*" -Include '*.doc','*.docx'
$docs | Rename-Item -NewName { "{0}{1}" -f $_.Basename.Split('_')[1],$_.Extension }
The important things to remember is that in order to use the -Include switch, you need an * at the end of the -Path value.
Explanation:
-Filter allows us to filter on names that contain two underscores separating three substrings.
-Include allows us to only list files ending in extensions .docx and .doc.
Rename-Item -NewName supports delayed script binding. This allows us use a scriptblock to perform any necessary operations for each piped object (each file).
Since the target files will always have two underscores, the .Split('_') method will result in an three index array delimited by the _. You have specified that you always want the second delimited substring and that is represented by index 1 ([1]).
The format operator (-f) puts the substring and extension together, completing the file name.

How would I specify a directory to run a PowerShell script that would edit file extensions?

I am new to PowerShell and new to IT. I've been asked by my boss to write a PowerShell script that will identify filenames that have no file extension and then change them to .PDF files. After doing some research online I've found a script that had a similar purpose and tried to tailor it to my needs:
$proj_files = Get-ChildItem | Where-Object {$_.Extension -eq "."}
ForEach ($file in $proj_files) {
$filenew = $file.Name + ".pdf"
Rename-Item $file $filenew
}
My first question is does the logic in this script make sense? Is "Extension -eq "." the correct syntax to specify a filename with no extension? My other thought was to use Extension -eq "null" or something similar. If I do need to use a null value, what would that look like? My other question is how would I specify a given directory for this script to search through, or would I even need to? My thought here would be to specify the path under Get-ChildItem, like so: $proj_files = Get-ChildItem -Path C:\Users\mthomas\Documents | Where-Object {$_.Extension -eq ".'} Does that seem correct? I am hesitant to test this out before getting a second opinion because I don't want to change every file extension on my computer or something stupid like that. Anyhow, thanks everyone for the help.
You can do something like the following to find files in a directory without an extension, and rename them to have a PDF extension:
$directory = "C:\Path\To\Directory"
Get-ChildItem -File $directory | Where-Object { -Not $_.Extension } | Foreach-Object {
$_ | Rename-Item -NewName "$($_.Name).pdf"
}
Let's break this down
$directory = "C:\Path\To\Directory"
This is where we set the directory we want to locate files without extensions in. It doesn't have to be set as a static variable but since you are just getting your feet wet with Powershell this keeps it simple.
Get-ChildItem -File $directory
Get-ChildItem is the cmdlet which is used to list directory contents (also aliased to gci, ls, and dir). -File tells it to only list files, and $directory references the directory we want to search from, which we set above. Note that Get-ChildItem might behave differently depending on the provider (for example, you can also use Get-ChildItem on a registry key), but if you are working with a filesystem path you do not need to worry about additional providers for this case.
|
Passes the previous output down the pipeline. This is a common operator in Powershell, but basically you can string commands together using it. You can read more about the pipeline at https://learn.microsoft.com/en-us/powershell/scripting/getting-started/fundamental/understanding-the-windows-powershell-pipeline?view=powershell-6
Where-Object { -Not $_.Extension }
Where-Object evaluates a condition on one or more items, and filters out items that do not meet the condition. Since Get-ChildItem can return one or more files, we use the -Not operator in the ScriptBlock (denoted by {} and make sure that there is no extension on the file. $_, or $PSItem, is a special variable used by the pipeline, in this case $_ equals each item returned by Get-ChildItem. The Extension property exists on files returned by Get-ChildItem, and will be blank, or evaluated as $False. So filtering on -Not $_.Extension is the same as saying to only match objects that are missing a file extension. Where-Object can be read about in more detail here: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/where-object?view=powershell-6
Foreach-Object { SCRIPTBLOCK }
Similar to Where-Object, but runs code for each object in the pipeline rather than evaluating and filtering out objects which don't match a condition. In this case, we pipe the each file without an extension to Rename-Item, which I'll break down further below. More information on Foreach-Object can be read about here: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/foreach-object?view=powershell-6
$_ | Rename-Item -NewName "$($_.Name).pdf"
Rename the current file in the Foreach-Object block to the new name with .pdf appended. The "$( ... )" is called a sub-expression, which is a string interpolation technique that lets you run a command within a string, and make its output part of the string. You could achieve the same effect by doing $_ | Rename-Item -NewName ( $_.Name + ".pdf" ) which just adds a .pdf to the end of the current name.
Summary
The pipeline is a very powerful tool in Powershell, and is key to writing efficient and less bloated scripts. It might seem complex at first, but the more you use it the less daunting it will seem. I highly suggest reading the additional documentation I linked to above as it should help fill in any gaps I may have missed in my explanations above.
To simplify the breakdown above, the command does this, in this order: Gets all files in the specified directory, selects only the files that do not have an extension, then renames each file found without an extension to have a .pdf at the end.
The logic in the script - the overall shape - makes understandable sense, but is not right for it to work as you intend.
Testing on my computer here:
new-item -ItemType File -Name 'test'
get-item test | format-list *
get-item test | foreach { $_.extension; $_.Extension.length; $_.extension.GetType().name }
a file with no extension shows up with an empty string (blank content, length 0, type String, so your where-object { $_.Extension -eq "." } needs to be looking for "" instead of ".".
But:
Get-ChildItem | Where-Object { $_.Extension -eq '' }
shows me some folders as well, because they also have no extension in their name, so you might want Get-ChildItem -File to restrict it to just files.
how would I specify a given directory for this script to search through, or would I even need to?
It would run in the current directory, whichever shows up in your prompt PS C:\wherever> so if you need it to run somewhere else, yes you'd need to change to that folder or specify in get-childitem -LiteralPath 'c:\path\to\wherever'. You haven't mentioned subfolders, if you need those included, get-childitem -Recurse switch as well.
Speaking of subfolders, your $filenew = $file.Name + ".pdf" only makes sense in the current directory, I think it would work better if you used the full filename including path, so they definitely get renamed in the same place they were found $filenew = $file.FullName + ".pdf"
Is "Extension -eq "." the correct syntax to specify a filename with no extension?
Being careful here, what you wrote in your question was correct syntax but incorrect string content. What you've written here with quotes on the left of Extension is incorrect syntax.
My other thought was to use Extension -eq "null" or something similar. If I do need to use a null value, what would that look like?
And being careful here, "null" is not a null value, it's a string containing the four letter word 'null'.
You don't need to use a null value here, normally if you do it looks like $null, but in this case you could use where-object { [string]::IsNullOrEmpty($_.Extension) } but there's no benefit to it, I think.
And, as a stylistic choice, both "" and '' are strings, but "" can contain variables and sub-expressions, so if you have plain text it's a neat habit to use '' for it because it makes it clear to the reader that you intend there to be nothing special happening in this string.
Then your code, with parameter names given, looks more like:
$proj_files = Get-ChildItem -LiteralPath 'C:\Users\mthomas\Documents' |
Where-Object {$_.Extension -eq '.'}
foreach ($file in $proj_files)
{
$filenew = $file.FullName + '.pdf'
Rename-Item -LiteralPath $file.FullName -NewName $filenew
}
If you want to see what it will do, use -WhatIf on the end of Rename-Item:
Rename-Item -LiteralPath $file.FullName -NewName $filenew -WhatIf
Then it won't make the changes, just tell you what it would do.
I am hesitant to test this out before getting a second opinion because I don't want to change every file extension on my computer or something stupid like that
Sensible. But internet people are going to tell you to test their code before running it, because ultimately it's your responsibility to safeguard your files, rather than trust random code from the internet, so having test folders, having a spare machine, having a good backup, playing with PowerShell in pieces until you are happy with what they do, they're all good habits to get into as well.