Re: GNU awk ver. 3.1.6 OFS-related bug

[Aharon Robbins]

In article <address@hidden>,
George Zarkadas  <address@hidden> wrote:
>-=-=-=-=-=-
>
>Στις 08-03-2011, ημέρα Τρι, και ώρα 23:34 +0000,
>ο/η Aharon Robbins
>έγραψε:
>> In article <address@hidden>,
>> Andreas Schwab  <address@hidden> wrote:
>> >George Zarkadas <address@hidden> writes:
>> >
>> >> Awk does not honor OFS assignments in the BEGIN block (when FS is also
>> >> previously set), unless a statement inside the applied rule's action
>> >> forces record reconstitution. 
>> >
>> >Correct.  $0 is only rebuilt if a field is changed.
>> 
>> Just to make it 100% clear - the reported behavior is not a bug.
>> $0 is the full record, including leading and trailing and intervening
>> whitespace.
>> 
>> Thanks for taking the time to send in a report.
>> 
>> Arnold
>
>Just a final clarifying note:
>
>The bug is (IMHO of course) in that the behavior in question
>is not anticipated here. To explain briefly:
>
>One would expect a simple program like this (I reduce here
>the case to the bare minimum), a record/field separator 
>transformation, to succeed:
>
>BEGIN {
>       RS=""
>       FS="\n"
>       ORS="\n"
>       OFS="\177"
>}
>{
>       print
>}
>
>especially when reading the section "4.3 Output Separators"
>of the manual and seeing: 
>
>"...In order to change how output fields and records are 
>separated, assign new values to the variables OFS and ORS. 
>The usual place to do this is in the BEGIN rule (see 
>BEGIN/END),..."
>
>as well as a successful example of issuing: "{ print $1, $2 }".
>
>I believe that if it is judged that the implementation is
>correct as is and should not change, at least the documentation 
>at this point should be amended to highlight this case: that
>a $1=$1 is needed when one only needs to change output FS.
>
>(Of course at the time of issuing the report I was unsure of 
>the real cause and I just stated the facts as accurately as I 
>could).
>
>regards
>George Zarkadas

I can understand the confusion; I will try to improve the documentation
that changing OFS doesn't affect $0 until one of the fields is changed.

Thanks,

Arnold
-- 
Aharon (Arnold) Robbins                         arnold AT skeeve DOT com
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