Path: utzoo!attcan!uunet!mailrus!wuarchive!mit-eddie!uw-beaver!zephyr.ens.tek.com!tektronix!sequent!lugnut
From: lugnut@sequent.UUCP (Don Bolton)
Newsgroups: comp.unix.shell
Subject: Re: ok, i've got a question...
Message-ID: <43113@sequent.UUCP>
Date: 27 Sep 90 22:05:49 GMT
References: <42900@sequent.UUCP> <9651@jpl-devvax.JPL.NASA.GOV> <42947@sequent.UUCP> <1990Sep27.170227.5257@athena.mit.edu>
Reply-To: lugnut@sequent.UUCP (Don Bolton)
Organization: Sequent Computer Systems, Inc
Lines: 85

In article <1990Sep27.170227.5257@athena.mit.edu> jik@athena.mit.edu (Jonathan I. Kamens) writes:
>In article <42947@sequent.UUCP>, lugnut@sequent.UUCP (Don Bolton) writes:
>|> awk -f filebelow <oldlist >newlist
>|> 
>|> { for (i = 1; i <= NF; i = i + 1)
>|>      { if (i >= NF)
>|> 	  printf("%s",$i)
>|>      else
>|> 	  printf("%s ", $i) 
>|>      }
>|> printf("\n")
>|> }
>|> 
>|> course I assume the "null" characters are just blanks here
>
>  First of all, the assumption that the nulls are supposed to represent blanks
>in the text is faulty, and is (as far as I can tell) in no way a valid
>assumption given the data that was provided by the original poster. 
>Furthermore, there is no reason to make that assumption, since other posters
>have posted solutions which do not.
>
This is true, alas, I work with RDBMS products such as Oracle and Informix
and am used to seeing nulls represented as blank spaces.

>  Note that the original poster did not say that he wanted to replace the
>nulls with spaces (which is what your solution does), he said that he wanted
>to remove them altogether.
>
Actualy what my program does do is strip out multiple blanks and replaces
them with one blank space.

>  Second, as Larry Wall already pointed out, your solution will coredump on a
>lot of systems.
>
This is not a point I would have considered, as it runs fine on my machine
and is really merely a modified example from the awk programming language
book I have.

>  Third, your solution deletes extra space between words.  If I have a line
>which appears as "foo          bar" in the input, it will appear as "foo bar"
>in the output.
>
Which was my intent. (I did do *something* right) :-)

>  Fifth, the awk on my system (4.3BSD) loses anything on the line after the
>first null.  Therefore, "foo^@^@^@bar" turns into "foo".  Presumably, your
>version doesn't do this, else you wouldn't have posted your solution, so you
>have portability concerns.  There are still other versions of awk (e.g. GNU
>awk) that keep nulls intact.
>
Don't know bout this one....

>  Sixth, the awk code you posted is suboptimal in at least three different
>ways.  For example, if you look runs from 1 to NF, how can i ever be greater
>than NF inside the body of the loop?  Here's a piece of code that does the
>same thing (although, like I've said, I don't think it's the right thing to
>do):
>
i cannot be greater than NF, this bozo hosehead here tried to use an
assignment operand as an equality operator, in a fit of "what the fu**",
I tossed in the > and bingo it ran.

16 months ago I was a telemonkey (read telemarketer) with <NULL programming
experience. Because of the application generators associated with the RDBMS
packages I found RDBMS programming to be easy and a LOT more enjoyable than
dialing for dollars. I'm still bumping my way through shell programming,
though not an expert, I can do whatever I need to with it. awk is something
I just recently started playing with and the program you saw was my first
forray beyond {print "some text", $1} useage..

I'll learn, thanks for the pointers..

>   {
>      for (i = 1; i < NF; i++)
>         printf("%s ", $i)
>      printf("%s\n", $NF)
>   }
>
>-- 
>Jonathan Kamens			              USnail:
>MIT Project Athena				11 Ashford Terrace
>jik@Athena.MIT.EDU				Allston, MA  02134
>Office: 617-253-8495			      Home: 617-782-0710

Half lug, half nut