[RndTbl] Wrong time of night for doing regex?

Dan Martin dan at martinmedcorp.com
Sat Jan 4 10:59:02 CST 2020


Hi Hartmut

I am not familiar with your replacement syntax \1\s0\2\s

Rubular shows the groups as:
1  From AncientBBS1
2  Thu
3  Jan
and 3 others

and for the truncated expression:
1  Jan
2  2

I find rubular a convenient online tool for checking regex
https://rubular.com/

-Dan

On Sat, Jan 4, 2020 at 10:27 AM Hartmut W Sager <hwsager at marityme.net>
wrote:

> This might be the wrong time of night for doing regex (i.e., my mistake),
> or my trusty Vedit text editor has a bug in its regex implementation.
>
> Original search string: ^(From
> AncientBBS[1-2])\s+(Sun|Mon|Tue|Wed|Thu|Fri|Sat)[\s\,]+(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+([0-9][0-9]|\s[0-9])[\s\,]+(19[0-9][0-9])[\s\,]+([0-9][0-9]\:[0-9][0-9]\:[0-9][0-9])\s*$
> Replacement string: <Nah, skip it>
>
> The above search string gives a syntax error.  I am a bit suspicious of
> the ([0-9][0-9]|\s[0-9]) group re operator precedence of the "or", and
> proceeded to stepwise simplification to narrow it down.  I finally got down
> to:
>
> Search string:
> (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+([0-9])[\s\,]+
> Replacement string: \1\s0\2\s
>
> The new search works fine (as did some of the previous stepwise simplified
> ones), but the replacements are baffling me.
> The line
> From AncientBBS1 Thu  Jan  2, 1986  20:50:00
> gets changed to
> From AncientBBS1 Thu   02 1986  20:50:00
>
> I.e., the variable \1 seems to get lost.  In my previous stepwise
> simplified cases, multiple variables got lost when the search worked at all.
>
> Why am I doing this?  I need to massage some old BBS messages into the
> retarded mbox format, whose date format (on the "From " line) of "Tue Nov
> 05 19:02:00 1985" is particularly illogical.  Be that as it may, The two
> sources of these messages I am processing had further sloppiness in their
> dates, done by some ancient BBS bozos.  I did successfully fix a lot of
> that already with regex.
>
> Hartmut W Sager - Tel +1-204-339-8331
>
> _______________________________________________
> Roundtable mailing list
> Roundtable at muug.ca
> https://muug.ca/mailman/listinfo/roundtable
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://muug.ca/pipermail/roundtable/attachments/20200104/b6f829d5/attachment-0001.html>


More information about the Roundtable mailing list