Environment variable named !:: (exclamation mark + colon + colon)

Environment variable named !:: (exclamation mark + colon + colon)

[tzccinct]

Hi,

I have found an environment variable that has a strange name `!::' 
(exclamation mark + colon + colon) on my terminal (both mintty and Tera 
Term). The value is also strange, `::\' (colon + colon + backslash).

$ env | sort | head -n 3
!::=::\
_=/usr/bin/env
ALLUSERSPROFILE=C:\ProgramData

Is this an expected environment variable on Cygwin? If so, what is this for?

Best regards,
tzccinct

Re: Environment variable named !:: (exclamation mark + colon + colon)

[Csaba Raduly]

On Sat, 5 Dec 2020 at 15:25, tzccinct wrote:
>
> Hi,
>
> I have found an environment variable that has a strange name `!::'
> (exclamation mark + colon + colon) on my terminal (both mintty and Tera
> Term). The value is also strange, `::\' (colon + colon + backslash).
>
> $ env | sort | head -n 3
> !::=::\
> _=/usr/bin/env
> ALLUSERSPROFILE=C:\ProgramData
>

This seems to be related :
https://unix.stackexchange.com/questions/251174/strange-environment-variable-in-cygwin

Csaba
-- 
You can get very substantial performance improvements
by not doing the right thing. - Scott Meyers, An Effective C++11/14 Sampler
So if you're looking for a completely portable, 100% standards-conformant way
to get the wrong information: this is what you want. - Scott Meyers (C++TDaWYK)