POSIX filenames and invalid characters on DrvFs

[billziss-gh]

A brief description

POSIX allows all characters in filenames except / and \0. However WSL follows Windows guidelines on DrvFs and cannot create filenames that contain any of the NTFS invalid characters: < > : " / \ | ? * or those with values in the range [0, 31].

POSIX filenames should be fully supported. This should be done in a backwards compatible manner as this has been done before by Cygwin and (I believe?) by Services for UNIX: https://www.cygwin.com/cygwin-ug-net/using-specialnames.html

[NOTE: despite my GitHub badge I am not affiliated with Cygwin other than as a user.]

I am aware of #1514.

Expected results

From a Cygwin prompt:

billziss@windows:~$ touch CON
billziss@windows:~$ ls -l CON
-rw-r--r--+ 1 billziss None 0 Mar 23 10:51 CON
billziss@windows:~$ rm CON
billziss@windows:~$ touch C:
billziss@windows:~$ ls -l C:
-rw-r--r--+ 1 billziss None 0 Mar 23 10:51 C:
billziss@windows:~$ rm C:

Actual results (with terminal output if applicable)

From a WSL prompt (on DrvFs):

billziss@WINDOWS:/mnt/c/Users/billziss$ touch CON
billziss@WINDOWS:/mnt/c/Users/billziss$ ls -l CON
-rwxrwxrwx 1 root root 0 Mar 23 10:48 CON
billziss@WINDOWS:/mnt/c/Users/billziss$ rm CON
billziss@WINDOWS:/mnt/c/Users/billziss$ touch C:
touch: setting times of ‘C:’: No such file or directory

Your Windows build number

14393

[therealkenc]

Same as #1514

[billziss-gh]

@therealkenc thanks.

I am aware of #1514. However this issue is specifically about using the same filename mapping as Cygwin (and SFU?).

EDIT: @doehrm hinted at the proposed solution in this message

[billziss-gh]

Is there an actual resolution to this?

[benhillis]

@billziss-gh - Yes. Judging by the duplicate item linked this is fixed in 1803.

[billziss-gh]

Thank you for the clarification.