From: Zach Dennis <zdennis@...>
Date: 2005-03-04T01:10:18+09:00
Subject: Re: Env class bug?

ruby@eq.cz wrote:
> Adriano Ferreira wrote:
> 
>> Etc.getlogin likely "implements the C library function of the
>> same name, which on most systems returns the current login
>> from /etc/utmp, if any".
>> With a 'su' you changed the real user user id and getlogin() returns
>> the name associated with the current login activity. So as Guy Decoux
>> said it is the expected behaviour and
>>         Etc.getpwuid(Process::Sys.geteuid)[:dir]
>> is what you want.
>>
> 
> Ok, now I see. 'su -', according to man page, should ``Simulate a full 
> login.''. On the other hand, 'getlogin', according to 'Linux 
> Programmer's Manual', ``returns  a pointer to a string containing the 
> name of the user logged in on the controlling terminal of the process''.
> 
> 'NetBSD System Calls Manual' is explicit about this behaviour:
> ``The name is normally associated with a login shell at the time a 
> session is created, and is inherited by all processes descended from the 
> login shell.  (This is true even if some of those processes assume 
> another user ID, for example when su(1) is used.)''
> 
> Thanks for your help, guys, and sorry for the noise.

Not noise, I learned from this. Thanks for posting this to the list so I 
could share in reading the replies and reasoning!

Zach