From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-0.8 required=5.0 tests=BAYES_00,INVALID_DATE
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,447a948bb64464c3
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 1994-10-14 15:30:57 PST
Newsgroups: comp.lang.ada
Path: 
 bga.com!news.sprintlink.net!howland.reston.ans.net!pipex!uunet!aadt!ventures!a311581
From: a311581@ventures.NoSubdomain.NoDomain (Kevin Cline)
Subject: Re: I have a question...
Message-ID: <CxoM71.B41@uunet!aadt>
Sender: a311581@ventures (Kevin Cline)
Organization: American Airlines Decision Technologies
References: <1994Oct07.034523.161470@zeus.aix.calpoly.edu>
 <EMERY.94Oct12173346@goldfinger.mitre.org>
Date: Fri, 14 Oct 1994 21:25:49 GMT
Date: 1994-10-14T21:25:49+00:00
List-Id: <comp.lang.ada>

In article <EMERY.94Oct12173346@goldfinger.mitre.org>, emery@goldfinger.mitre.org (David Emery) writes:
|> The easiest way to 'solve' this problem is to expand the "~" into the
|> home directory.  The environment variable "HOME" contains the pathname
|> of the home directory.  Thus it's pretty trivial to implement an
|> operation that replaces (all) occurances of "~" in a pathname with the
|> string value of HOME.  
|> 
|> To be more accurate/precise, the best thing to do is to obtain the
|> pathname to the home directory from the /etc/passwd file, since the
|> value of HOME could have been changed by the user.

It is not a good idea to read /etc/passwd.  Use getpwent(2).  It knows
about NIS.

Actually, various UNIX shell flavors differ in their interpretation of ~.
The c-shell always replaces ~ with the value of the home variable,
or if that is not set (the usual case) then with the user's login directory.
The Bourne shell does not support ~ at all.
The Korn shell replaces ~ with the value of the HOME variable.
GNU bash replace ~ with the value of the HOME environment variable.

You should probably use the HOME environment variable, since users that
change it are probably pretending to be someone else for a good reason.

Kevin Cline