PowerShell command to add character to filename at specific position

Question

I'd like to add underscore character "_" at position 22 of a filename. What would be the PowerShell command to do it?

Please read the question - I don't want to rename "a" to "b". I want to add underscore at specific position. — Rayearth
– Rayearth, Commented Feb 2, 2016 at 8:43
I've read the question. It's not clear what you are having difficulty with. If I wanted to rename a file as requested then I would 1) Get the filename into variable called $before 2) Create another variable with the filename modified as intended in a variable called $after. 3) Call Rename-Item $before $after. If you are following a similar process to me then you haven't told us what you are having trouble with 1, 2 or 3? As you ask about renaming and not about creating a string with an underscore in it at a particular position I am assuming it is 3 that you have trouble with. — DanL
– DanL, Commented Feb 2, 2016 at 8:48

Kiran Reddy · Accepted Answer · 2016-02-02 09:11:35Z

5

alternately you can also make use of the string method insert

Get-Item -Path $Path | 
  Rename-Item -NewName {$_.BaseName.insert(22,'_') + $_.Extension} -WhatIf

note: remove -whatif to apply the rename

answered Feb 2, 2016 at 9:11

Kiran Reddy

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1 Comment

Thank You. This is exactly what I was asking for. Have a good day, kind sir.

Martin Brandl · Accepted Answer · 2016-02-02 09:42:46Z

1

You could use -replace and a simple regex to achieve that.

In the following example, I first retrieve the file using the Get-Item cmdlet and rename it using Rename-Item:

Get-Item $YOURPATH | % { $_ | Rename-Item -NewName ($_.Name -replace '^([\S\s]{22})', '$1_')}

You may have to add a check whether the file name is long enough, otherwise it could happen, that you rename the file extension or nothing...

answered Feb 2, 2016 at 8:56

Martin Brandl

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This one does not add underscore, it replaces any character at position 22 with the underscore character.

Sonoo Kumar · Accepted Answer · 2020-01-30 11:05:33Z

0

below script will add '-' at position 3 and 6 and 9 and 12 and 15

from: s270120070336.bmp

to: s27-01-20-07-03-36.bmp

Get-ChildItem -Path 'C:\users\sonook\desktop\screenshot' -Filter '*.bmp' |

ForEach-Object { $_ | Rename-Item -NewName {$_.BaseName.insert(3,'-').insert(6,'-').insert(9,'-').insert(12,'-').insert(15,'-') + $_.Extension}}

answered Jan 30, 2020 at 11:05

Sonoo Kumar

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