Problem with tar version 1.29 (in Cygwin 3.6 64 bit) in extracting sym-link files

[Andrey Repin]

Greetings, vinay Hegde!

Please no top-posting in this list.

> On Fri, Oct 2, 2020 at 9:13 PM Eliot Moss wrote:
>>
>> On 10/2/2020 11:26 AM, vinay Hegde via Cygwin wrote:
>> > Hi Cygwin Team,
>> > In Cygwin 3.6, I am facing an issue while using tar.exe for extracting
>> > .tar.z file.
>> >
>> > Issue summary:
>> > When I use 'tar.exe' to extract the .tar.z file, it extracts all files
>> > including symlinks. But symlink file size will be 0KB & it throws
>> > error 'The file cannot be accessed by the system', if I try to open in
>> > any Windows editor like notepad or notepad++
>> >
>> > Below are the details:
>> > -   OS: Windows 2019
>> > -   Cygwin version installed: 3.6 (tar version: 1.29)
>> > -   Command used to extract the tar file is: tar -zxvf jre64.tar.Z
>> > -   'ls -l' on the extracted directory shows:
>> > lrwxrwxrwx  1 etbuild Domain Users      8 Jul 10  2017 ControlPanel -> jcontrol
>> > -rwxr-xr-x+ 1 etbuild Domain Users   7734 Mar 15  2017 java
>> > -rwxr-xr-x+ 1 etbuild Domain Users 128791 Mar 15  2017 javaws
>> > -rwxr-xr-x+ 1 etbuild Domain Users   6264 Mar 15  2017 jcontrol
>> >
>> > -     As you can see 'ControlPanel' is a symlink file with 0KB
>> > (8Bytes) size. This file, I cannot open in any Windows editor. It
>> > throws error like ''The file cannot be accessed by the system'
>> >
>> > -    However, I can open this file in vi editor or I can 'cat' this.
>> >
>> > -    Earlier, I was using Cygwin version 1.7 (tar version: 1.27) & in
>> > that, this issue was not there. Symlink file size was 1KB & I could
>> > open it with any Windows editor.
>> >
>> > Please suggest what needs to be done to fix this issue.
>>
>> Hi, Vinay - Cygwin can use, and create, a variety of forms of links.  Some of these are understood
>> by Windows tools, some not.  I suggest you read in the Cygwin documentation about symlinks and
>> decide what kind are best for you.  Then you'll need to set that up, delete the existing link, and
>> re-create it.  I personally run with CYGWIN=winsymlinks:native, but as we say in Internet land, YMMV.
>>

> Hi Eliot Moss,
> Thank you very much for the quick response & the information.It really helped.
> I just set 'CYGWIN=winsymlinks:lnk' & I am now able to open sym-link
> file. Both 'CYGWIN=winsymlinks:lnk' & 'CYGWIN=winsymlinks' are working
> for me.
> But it creates a shortcut(not the regular file). Hope it won't impact
> my existing setup.

> But both  'CYGWIN=winsymlinks:native' (which is default I believe) &
> 'CYGWIN=winsymlinks:nativestrict' are not working for me. Just to
> understand, In what OS environment/File System 'native' will work?

Given enough permissions, "native" will work everywhere, it will create native
symlink, but failing that, it will fall back to creating Cygwin link.

LNK is an Explorer shortcut, which would work with many programs outside
Cygwin, but not necessarily with your one.

See https://cygwin.com/cygwin-ug-net/using.html#pathnames-symlinks as well as
https://cygwin.com/cygwin-ug-net/using-cygwinenv.html 


-- 
With best regards,
Andrey Repin
Sunday, October 4, 2020 7:47:13

Sorry for my terrible english...