Newsgroups: comp.unix.admin
Subject: Re: rsh like command with rlogin environment
Summary: 
Expires: 
References: <1992Jul28.154242.4135@ilinx.wimsey.bc.ca>
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Organization: Princeton University
Keywords: rsh rlogin

In article <1992Jul28.154242.4135@ilinx.wimsey.bc.ca> brian@ilinx.wimsey.bc.ca (Brian J. Murrell") writes:
>I have this problem I'm sure other people have run into.  I want to be able
>to do an rsh command to another machine in the office, but the command I want
>to execute is interactive.  rsh doesn't work!!  However if I rlogin to the 
>machine and then execute the command and then log out, this works (obviously).
>
>What I want to be able to do is rsh foo -l brian bar to execute command 
>bar on machine foo, with id of brian, with the command bar being interactive.
>
>I figured what I really need is to be able to do rlogin foo -l brian bar.
>Unfortunately, rlogin doesn't support having a command to run when the user
>actually gets logged onto machine foo.

	Hear, hear!  I have wondered the same thing myself...  I can
	think of 4 solutions, at least 1 of which is an ugly hack. :-)
	I also have a few questions...

(1) Modify rsh so that instead of doing line-by-line buffering, it sends
    each character as it is typed.  Note that, with this type of solution,
    your .login/.profile file is never sourced.  Would in.rshd need to be
    changed for this?

(2) Modify rlogin so that you can specify a command to run.  Might one get
    away with only changing rlogin and not messing with in.rlogind?

(3) Combine the functionality of rsh and rlogin into one program with flags
    to specify what size buffers to use, and whether to execute a program
    right away or just start up an interactive shell.  This could take some
    work -- but -- why did the original designers choose to seperate rsh
    and rlogin in the first place?

(4) Use an shell script hack.  [Beware: I haven't tested this]  Create a
    `myrlogin' shell script which rsh's over to the new machine, makes a
    file (with a standard filename, under your home directory) which has
    the name of the interactive command in it (for instance, vi)    Then
    have the script do a rlogin.  Now make your .login/.profile check if
    the standard file exists - if it does, exec the command named there
    from your .login/.profile.  Whammo!  The new `myrlogin' shell script
    *should* be useable in the form `myrlogin newhost -l me trn' or
    somesuch.  Anyone see any problems with this approach?  (besides the
    fact that its ugly :-)

	Any other ideas?  And most importantly, why CAN'T you specify an
	interactive process to run remotely?  Is this a basic design issue?

--------------------------------------------------------------------------------
David Wagner            dawagner@phoenix.princeton.edu (or wagner@nisc.jvnc.net)