Re: awk: switch - case statement (GNU Awk 5.0.1, API: 2.0 (GNU MPFR 4.0.2, GNU MP 6.2.0) - Linux Ubuntu 20.04

[Manuel Collado]

El 27/06/2020 a las 10:35, Peter Brooks escribió:
> I'm finding myself baffled. I've never used the awk 'switch' statement
> before, so I may be doing something wrong, but it seems bizarre to me.
> Here's my test:
>
> BEGIN {
> > fred="hello";
> > switch (fred){
> > case "jim": print "Jim";
> > case "hello": print "Hello";
> > case "fred" : print "fred";
> > }
> > }
>
> The output is:
>
> $ gawk -f $(pwd)/case.awk </dev/null
> > Hello
> > fred
>
> I'm completely baffled. I'd expect the output to be only the 'Hello'!

From the gawk manual:

"Control flow in the switch statement works as it does in C. Once a
match to a given case is made, the case statement bodies execute until a
break, continue, next, nextfile, or exit is encountered, or the end of
the switch statement itself."

So you need:

BEGIN {
   fred="hello";
   switch (fred){
     case "jim": print "Jim"; break
     case "hello": print "Hello"; break
     case "fred" : print "fred"; break
   }
}

--
Manuel Collado - http://mcollado.z15.es