Bug in function match() ?

[Canarecci Mauro]

Dear Sirs,
I'm having a weird behavior with the match() function

I'm using GAWK 5.1.0 in Windows 10.
GAWK was compiled with MinGW

Running the following program (test1.awk)

BEGIN {
          # convert a date string to ISO format
           date="12/31/2023"
           if 
(match(date,/^(0?[1-9]|1[12])\/(0?[1-9]|[12][0-9]|3[01])\/([1-2][0-9]{3})$/,D)!=0)
 {
                        print D[3] "-" D[1] "-" D[2]
                        }
                }
I get the following output :
2023-12-31

as expected

However, when I run (test2.awk)

BEGIN {
           # convert a date string to ISO format

           
date_regex=/^(0?[1-9]|1[12])\/(0?[1-9]|[12][0-9]|3[01])\/([1-2][0-9]{3})$/
           date="12/31/2023"
           if (match(date, date_regex, D)!=0) {
                        print D[3] "-" D[2] "-" D[1]
                        }
                }

I get the following output :
--

That depends on the facts that the matched subexpressions don't get assigned to 
the array D, although "date" matched "date_regex" as expected.

Although I didn't run the very latest version of gawk, I haven't found any 
reference to this behaviour before, or a fix issued to solve a problem like 
this.
I hope this, if confirmed as a bug, could help improve gawk.

Regards

MAURO CANARECCI


Gruppo TIM - Uso Interno - Tutti i diritti riservati.

Questo messaggio e i suoi allegati sono indirizzati esclusivamente alle persone 
indicate. La diffusione, copia o qualsiasi altra azione derivante dalla 
conoscenza di queste informazioni sono rigorosamente vietate. Qualora abbiate 
ricevuto questo documento per errore siete cortesemente pregati di darne 
immediata comunicazione al mittente e di provvedere alla sua distruzione, 
Grazie. 

This e-mail and any attachments is confidential and may contain privileged 
information intended for the addressee(s) only. Dissemination, copying, 
printing or use by anybody else is unauthorised. If you are not the intended 
recipient, please delete this message and any attachments and advise the sender 
by return e-mail, Thanks.

Rispetta l'ambiente. Non stampare questa mail se non è necessario.

test2.awk
Description: test2.awk

test1.awk
Description: test1.awk