Login shell?

[James Logan III]

In article <1623 at solo10.cs.vu.nl> maart at cs.vu.nl (Maarten Litmaath) writes:
>In article <1217 at vsedev.VSE.COM> logan at vsedev.VSE.COM (James Logan III) writes:
>\... If you just want to find out what if the current
>\shell is indeed the shell spawned by init(1M) (via getty(1M), login(1)),
>\then just write a simple C program like this:
>\--------
>\#include <stdio.h>
>\
>\main()
>\{
>\	if (getppid() == getpgrp())
>\		exit(0);
>\	exit(1);
>\}
>
>1)
>	Why #include <stdio.h>?

It's not necessary, I just always need it when I don't already have it,
so it's just a habit, I guess.  It doesn't hurt anything and it will only
take a fraction of a second longer to compile it.  In addition, if he
adds an fprintf(), the program won't compile without it since the
type "FILE" will be undefined.

I wouldn't suggest #including every header file you might ever need,
but this one is so often used, why not?

>2)
>	This scheme won't work for rsh/rlogin.

It works just fine for rlogin, thank you.  I just tested it on my
system.  

Since you don't have a true session with rsh it will indicate
correctly that the program running is not your login shell.  

			-Jim
-- 
Jim Logan		logan at vsedev.vse.com
(703) 892-0002		uucp:	..!uunet!vsedev!logan
			inet:	logan%vsedev.vse.com at uunet.uu.net