I am creating a tool and the tests on Windows do not work correctly. The reason is that there is a ';' at the end of the $PATH (the environment variable). However, in the original $PATH (in the graphical editing interface), this ';' at the end of the $PATH does not appear anywhere. Apparently, Windows adds it automatically. Example of my personal computer $PATH (Windows 10):
Write-Output $env:PATH
C:\Python313\Scripts\;{other paths here...};C:\Users\SamiD\AppData\Local\Muse Hub\lib;
# This last ';' after '\lib' was automatically added in Windows, it was not manually placed by me at any time.
I would like to know what this ';' at the end alone means. Whether it is present in all versions of Windows, or only in the most recent ones. Or if it has any additional meaning. Or if it means nothing and I can safely remove it.
I guess it doesn't matter, but here are the specs:
Device Name: DESKTOP-TSN87E0
Processor: 11th Gen Intel(R) Core(TM) i9-11900F @ 2.50GHz 2.50 GHz
Installed RAM: 16.0 GB (usable: 15.9 GB)
Device ID: D5C5CD2A-33F2-434F-A073-99BDA9890470
Product ID: 00331-10000-00001-AA731
System Type: 64-bit operating system, x64-based processor
Pen and Touch: No pen or touch input is available for this display
PATH is a string variable serving the purpose of an array. The "elements" of this array are distintinguished using a delimiter character. On Unix-like systems, this delimiter is the colon :. On Windows, it is the semicolon ;. The delimiters are never part of the paths; in fact you can't even escape the delimiter character, so it is impossible to have an entry in the PATH with a delimiter character (at least on Unix).
The fact that there is a delimiter at the end of this strings makes little difference to the system, as any program parsing it can easily (and should) check for empty or malformed entries, and discard them. Why there might be a delimiter in the end might be because it is very common to update PATH through a syntax like PATH=<new_file_path>;PATH, which would add a delimiter in the end for the first file to be added.
I don't see a delimiter at the end on systems (Windows and Linux), but I see some back-to-back delimiters, possibly left over from deleted entries.
To answer your question, your tool should be able to disregard the delimiter characters. You should not have to remove it, as you can never guarantee other systems will not have one (or another "anomaly", like the double delimiter that I have).
Many languages have built-in methods to split delimited-strings into arrays.
Edit
I confirmed through my own experiments that:
The ;; entries and the trailing ; result in empty entries, which some OSs seemingly understand as the current directory (I could not find a good example for this). However, Windows already searches the current directory by default, and such entries on the PATH are unnecessarily at best. See this answer for reference.
As far as your tool is concerned, I can't comment how it should behave without knowing the exact behavior you are going for. But unless it is being designed to modify PATH somehow, I would recommend not relying on well-formed variables, and to simply discard or report invalid entries. There is no formal requirement that a PATH may not contain emptry or invalid paths.
If you are keen on removing empty paths from your PATH variable, I've encountered a few scripts and tools while I was looking for sources. I will not link any as they are easy to find and I did not personally verify any of them.
Side note: You can use path | wsl tr ";" "\n" in a Windows shell to display your PATH environment in multiple lines. This also shows the empty lines in the middle or at the end of PATH. The wsl tr ";" "\n" calls the tr command from WSL.