The two simplest use cases for the touch command are to:

1. Create one or more files, if they don’t exist;
2. Update the access date or modification date of files without changing their content.

To replicate these two cases in PowerShell, we make use of the LastWriteTime property of a FileSystemInfo object, as well as creating an empty file if one does not exist at the specified path.

You can add the following code to the Microsoft.PowerShell_profile.ps1 file in your <Users>\Documents\WindowsPowerShell\ folder:

You can now call it with either: Update-File file1.txt file2.txt or touch file1.txt file2.txt.

Couple of Points Worth Making

We name the function Update-File following the PowerShell pattern or verb-noun pair for commands and the Data Verbs section of Approved Verbs for Windows PowerShell Commands.

We set pass the -Encoding ascii to the Out-File command as the default encoding for Out-File is UTF-16 and some *nix transplant tools have troubles handling UTF-16 files because of the two byte-markers at the beginning of the file (for example webpack when bundling files).

Finally, credit goes to this answer on StackExchange’s superuser.