I want to filter only files and folders with name start with 2[A-Z] (uppercase only):

ls -recurse | Where-Object {$_.name -match '2[A-Z]'}

But it still returns lowercase files. Reading the -match parameter of Where-Object I don't see a way to fix this.

CodePudding user response：

PowerShell's comparison operators are case-insensitive by default, but they have c-prefixed variants that are case-sensitive, namely -cmatch in the case of the -match operator:

gci -recurse | Where-Object { $_.Name -cmatch '^2[A-Z]' }

• gci is used as the PowerShell-idiomatic alternative to the Windows-only ls alias for Get-ChildItem.

  • See the bottom section of this answer for more information on why aliases named for commands or utilities of a different shell or platform are best avoided.

• Regex assertion ^ is used to ensure that the pattern only matches at the start of file names.

Alternatively, use simplified syntax:

gci -recurse | Where-Object Name -cmatch '^2[A-Z]'