Re: RS='.^' apparently ignores the RS setting

[arnold]

Hi.

Ed Morton <mortoneccc@comcast.net> wrote:

> So I read 
> https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04_09
>  
> which I thought was saying you could use any character before the `^` 
> and it wouldn't match which was supported by this test:
>
>      $ printf 'ax^b\nax^b\n' | awk 'BEGIN{RS="x^"}{print NR, $0}'
>      1 ax^b
>      ax^b
>
> but then I can't explain this where gawk is apparently completely 
> ignoring the RS setting:
>
>      $ printf 'a.^b\na.^b\n' | awk 'BEGIN{RS=".^"}{print NR, $0}'
>      1 a.^b
>      2 a.^b
>
> Is that a bug?

No. ^ and $ are always metacharacters in EREs, even if that means
you can create nonsense regexps. You have to escape them to get
them to be treated literally:

$ printf 'ax^b\nax^b\n' | ./gawk 'BEGIN{RS="x\\^"}{print NR, $0}'
1 a
2 b
a
3 b

$ printf 'a.^b\na.^b\n' | ./gawk 'BEGIN{RS=".\\^"}{print NR, $0}'
1 a
2 b
a
3 b

HTH,

Arnold