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Re: [Bug-ed] GNU ed 1.11-rc1 released

From: Paul Jackson
Subject: Re: [Bug-ed] GNU ed 1.11-rc1 released
Date: Mon, 09 Feb 2015 04:28:52 -0600

Martin Guy wrote:
> I don't have the source of the original Berkeley ed any more

If my memory serves me, the original "ed" was written by someone in Bell Labs, 
New Jersey, and was part of the Unix that Ken Thompson took with him (Version 
6, on a 9 track tape, I presume) on a year long sabbatical to UC Berkeley in 
1976, to port it to a new PDP 11/70.  About the same time, they started 
replacing teletypes with ADM 3A glass terminals, and Bill Joy, a new student 
there, became frustrated with ed on a glass screen, so started hacking in line 
editing mode to form the basis of vi.

Also, if memory serves, those early versions of "ed" didn't have any 'z' 
command.    Indeed, I am pretty sure of that, as my fingers have hard coded 
microcode for all the original 'ed' commands, as of Version 6, and 'z' is not 
one of them.  Moreover, 'z' would make little sense on a teletype output 
device, the original home of 'ed'.

On the current question, I firmly recommend leaving the code 'as is', and if 
the documentation is unclear or doesn't match the code, fixing the 

By now, 'ed' has become hard coded in more places (and fingers of old men) than 
we could ever track down ... so best not change some rather arbitrary behavior 
of it.  Something will break, and the victims might never figure out what 
really happened.

When designing new code, one should strive to "get it right."  When maintaining 
old code, one should strive to "not break it."  The "standard" Unix text editor 
(as the man page used to describe it) definitely qualities as "old code."

                Paul Jackson

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