Lazarus

Programming => Operating Systems => Linux => Topic started by: AlexTP on June 17, 2021, 09:12:07 pm

Title: Get/set Unix file 'owner'?
Post by: AlexTP on June 17, 2021, 09:12:07 pm

CudaText runs 'pkexec /bin/cp old_filename new_filename'.
It works OK but the owner of that file changes from 'root' to my name.
Can I change the owner of a file?
Can I read the owner of a file?

Title: Re: Get/set Unix file 'owner'?
Post by: winni on June 17, 2021, 09:37:41 pm

Hi!

The unit BaseUnix has a wapper for the Unix command chown:

Code: Pascal  [Select][+][-]

1. Function  FpChown   (const path : RawByteString; owner : TUid; group : TGid): cInt;

Winni

Title: Re: Get/set Unix file 'owner'?
Post by: AlexTP on June 17, 2021, 10:00:02 pm

To run the 'pkexec --user username' I need the string-user-name of file owner. How to get it?

Title: Re: Get/set Unix file 'owner'?
Post by: skalogryz on June 17, 2021, 10:08:13 pm

don't you need elevated rights (sudo) to assign "root" as the owner?

Title: Re: Get/set Unix file 'owner'?
Post by: winni on June 17, 2021, 10:08:42 pm

Hi


Use the Unix command id:

To get the UserID:

Code: Bash  [Select][+][-]

1.  
2. id -u winni

To get the GroupId:

Code: Bash  [Select][+][-]

1. id -g winni

Winni

Title: Re: Get/set Unix file 'owner'?
Post by: winni on June 17, 2021, 10:10:14 pm

Quote from: skalogryz on June 17, 2021, 10:08:13 pm

don't you need elevated rights (sudo) to assign "root" as the owner?

Yes

Winni

Title: Re: Get/set Unix file 'owner'?
Post by: winni on June 17, 2021, 10:36:43 pm

Hi!

Oops - you need it vice versa.

For UserId 1000  you use:

Code: Bash  [Select][+][-]

1. grep - w 1000 /etc/passwd

It returns in my case:

Code: Text  [Select][+][-]

1. winni:x:1000:100::/home/winni:/bin/bash

which is:

Code: Text  [Select][+][-]

1. UserName:pwd:UserID:GroupID:comment:HomeDirectory:shell

Winni

Title: Re: Get/set Unix file 'owner'?
Post by: AlexTP on June 17, 2021, 11:21:28 pm

Thanks.
I found that 'pkexec /bin/mv' does NOT set root owner. But 'pkexec /bin/cp filename /etc/filename' does it! Solved.