Two problems with C & ULTRIX

[hoffman at hdsvx1.UUCP]

Someone please help me with a couple of irritating bugs that have turned up
in a program I wrote.  The program produces a constantly refreshed `curses'
display giving the current time & date, a "new mail" flag, a list of 
newsgroups with new USENET articles in them, and a list of the current
processes running on the machine, courtesy of `ps -uag'.  There is also
a command mode, which one enters via an INTERUPT (^C for me), which allows
one to escape to the shell, rn, or mail, and to reset certain parameters.

My problems:

(1) In command mode, I do a curses `getstr' to pick up a string from the user.
    My documentation says that `getstr' terminates with a \n, which is what I
    would like to see, but I find that I have to terminate with a \000 (^@)
    instead.  What am I doing wrong?

(2) I use fork and execl to enter rn, mail or the shell from command mode,
    as follows:

	shell(location,name)
	char *location,*name;
	{
	    int status;
	    if (!fork())
	    {
		execl (location, name, NULL);
	    }
	    wait(&status);
	}

    where `location' is the actual file name (e.g., "/usr/ucb/mail") and
    `name' is the command name (e.g. "mail").  This works great for the
    shell (csh) and for rn, but for mail it doesn't appear to do anything.
    However, I think it is spawning a process (I can see it in my ps listing).
    How do I get to it?  Why is mail different from rn and the shell?

(3) For my `ps' display, I use `popen' to start a pipe, and read the lines
    from `ps' and then display them.  This works fine, but every so often
    I get a message "/vmunix: No namelist" followed by either a hangup or
    a bus error.  Any insights, anyone?

The environment is ULTRIX, Release 2, running on a VAX/750.  I will be glad 
to send the source code for the whole program (~400 lines) to anyone who 
would like to examine it in depth, but I hope that won't be necessary.
-- 
 Richard Hoffman | "They sought it with thimbles, they sought it with care,
 Schlumberger WS | They pursued it with forks and hope;
 hdsvx1!hoffman  | They threatened its life with a railway share,
 713-928-4750    | They charmed it with smiles and soap."         (L. CARROLL)