renaming with regex in powershell


the puzzle is, how to rename a bunch of file with a certain criteria. In my case, i have the following structure (snippet) and I need to remove all the digits from the name

│ loremIpsum02_NEECA_Northern_Europe.xlsx
│ loremIpsum03_NEECA_Czech_Republic.xlsx
│ loremIpsum04_NEECA_Hungary.xlsx
│ loremIpsum05_NEECA_Poland.xlsx
│ loremIpsum06_NEECA_Romania.xlsx
│ loremIpsum07_NEECA_Bulgaria_Greece.xlsx
│ loremIpsum08_NEECA_Georgia.xlsx
│ loremIpsum09_NEECA_Kazakhstan.xlsx
│ loremIpsum10_NEECA_Russia.xlsx
│ loremIpsum29_NEECA_All.xlsx

│ loremIpsum17_AEM_Turkey.xlsx
│ loremIpsum18_AEM_Egypt.xlsx
│ loremIpsum19_AEM_Morocco_Mauretania.xlsx
│ loremIpsum20_AEM_Africa 1.xlsx
│ loremIpsum21_AEM_Africa 2.xlsx
│ loremIpsum22_AEM_Africa 3.xlsx
│ loremIpsum31_AEM_All.xlsx

1. mass renaming get-childitem (dir)

get-childitem -recurse | Rename-Item -NewName {$_.Name -replace '\d{2}', ''}
  • no loop structure necessary here (such as foreach-object)
  • the value of NewName is a script block that runs before the value is submitted to the NewName parameter
  • in the script block, the $_ the automatic variable represents each file object as it comes to the command through the pipeline
  • here, you use the -replace switch and regex literal to replace the 2 digits with an empty string
  • of course, '\d{2} can be replaced with any regex literal according to the current need
│ loremIpsum_NEECA_Northern_Europe.xlsx
│ loremIpsum_NEECA_Czech_Republic.xlsx
│ loremIpsum_NEECA_Hungary.xlsx
│ loremIpsum_NEECA_Poland.xlsx
│ loremIpsum_NEECA_Romania.xlsx
│ loremIpsum_NEECA_Bulgaria_Greece.xlsx
│ loremIpsum_NEECA_Georgia.xlsx
│ loremIpsum_NEECA_Kazakhstan.xlsx
│ loremIpsum_NEECA_Russia.xlsx
│ loremIpsum_NEECA_All.xlsx

│ loremIpsum_AEM_Turkey.xlsx
│ loremIpsum_AEM_Egypt.xlsx
│ loremIpsum_AEM_Morocco_Mauretania.xlsx
│ loremIpsum_AEM_Africa 1.xlsx
│ loremIpsum_AEM_Africa 2.xlsx
│ loremIpsum_AEM_Africa 3.xlsx
│ loremIpsum_AEM_All.xlsx

2. single rename with get-item

  • what I do is that I keep todo in a git repo of markdown files
  • all of the files begin with a timestamp yyyy-MM-dd, e.g. 2020-10-26
  • with a simple alias u and the filepath, I update the old date to the new date
function update-timestamp ($file) {
$today = Get-Date -Format yyyy-MM-dd
$regex = '\d{4}-\d{2}-\d{2}'
gi $file | ren -NewName {$_.Name -replace $regex, $today} -Verbose

3. sources

today I learnt… | as a support eng of the wonderful Snowplow Analytics, expect everything around modern (postmodern?) business intelligence

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