[comp.sys.amiga.tech] Symbolic Links and the AREXX: device

ranjit@grad1.cis.upenn.edu (Ranjit Bhatnagar) (09/06/89)

Here's some uses for symbolic links, sorted by obviousness.  If
you think of a symbolic link as just a way of making a file point
at another file, you miss the more exciting possibilities of the
Amiga's device space.

	ln -s file sys:foo
	ln -s file df0:foo/ick
	ln -s file pipe:input
	ln -s :dev/ttyd1 aux2:
	ln -s libs "arexx:showlist 'l'"
	ln -s everything "arexx:address command find : -print"
	ln -s "Monthly Report" "arexx:recalc.maxiplan"
	ln -s Booby "arexx:address command delete : all"
	ln -s :dev/texprinter "arexx:texify >prt:"

The really interesting ones depend on the "arexx:" device, whose
use is obvious.  It doesn't exist yet  - but I'm sure someone will 
invent it pretty soon.  Once "arexx:" exists, anyone can write a 
(slow) device handler without touching a compiler.  Using "assign"
effectively creates an independent handler process:

	assign outmail: "arexx:sendme.uucp"

 -- the sendme script waits for input instead of being reinvoked
 every time.

If anyone is inspired to write "arexx:" by this, please send me a
note.  It would be a character-stream device, like ser: or con:,
rather than a file-oriented device like df0: or ram:.

	- ranjit


* Ranjit Bhatnagar * 4211 Pine Street * Philadelphia, PA 19104 * 215-222-5767 *
"Trespassers w"   ranjit@eniac.seas.upenn.edu	mailrus!eecae!netnews!eniac!...
	   "Such a brute that even his shadow breaks things." (Lorca)

cosell@bbn.com (Bernie Cosell) (09/07/89)

In article <14083@netnews.upenn.edu> ranjit@grad1.cis.upenn.edu.UUCP (Ranjit Bhatnagar) writes:
}Here's some uses for symbolic links, sorted by obviousness.  If
}you think of a symbolic link as just a way of making a file point
}at another file, you miss the more exciting possibilities of the
}Amiga's device space.
}
}	ln -s file sys:foo
          ...

Assuming that you were referring to the Unix symbolic link command, I believe
that you got *every* one backwards.  The form is:
     ln [-s] <thing that exists> <newname it is to have>

  /Bernie\

ranjit@grad1.cis.upenn.edu (Ranjit Bhatnagar) (09/07/89)

In article <45274@bbn.COM> cosell@BBN.COM (Bernie Cosell) writes:
}In article <14083@netnews.upenn.edu> I wrote:
}}
}}	ln -s file sys:foo
}          ...
}
}Assuming that you were referring to the Unix symbolic link command, I believe
}that you got *every* one backwards.  The form is:
}     ln [-s] <thing that exists> <newname it is to have>

Absolutely.  I realized it a bit too late.  But you know what I mean!
 
	-ranjit


"Trespassers w"   ranjit@eniac.seas.upenn.edu	mailrus!eecae!netnews!eniac!...
	   "Such a brute that even his shadow breaks things." (Lorca)

shf@well.UUCP (Stuart H. Ferguson) (09/11/89)

+-- cosell@BBN.COM (Bernie Cosell) writes:
| In article <> ranjit@grad1.cis.upenn.edu.UUCP (Ranjit Bhatnagar) writes:
| }	ln -s file sys:foo
|           ...
| Assuming that you were referring to the Unix symbolic link command, I believe
| that you got *every* one backwards.  The form is:
|      ln [-s] <thing that exists> <newname it is to have>

This is one really DUMB thing that has bothered me more and more recently.
Mechanical engineers long ago invented polarized (or idiot-proof) plugs to
make it impossible to plug things in backwards.  Why can't the computer
clerisy come up with idiot-proof arguments lists!?  My favorite is "strcpy;"
I can *never* remember the order for the arguments.  And getting them wrong
will fry your code as bad as shorting any op-amp.

Pardon my outburst.
-- 
		Stuart Ferguson		(shf@well.UUCP)
		Action by HAVOC		(ferguson@metaphor.com)