Re: Read the input as a whole

[Ed Morton]

These kind of "how does awk work" questions would be far more 
appropriate to ask on Usenet at comp.lang.awk or on Stackoverlflow with 
the awk tag, by the way, rather then emailing the gawk providers bug 
mailing list with them.

    Ed.

On 6/11/2021 9:28 AM, Ed Morton wrote:
> The first (with `RS=""`) will read the first paragraph in the file, 
> not the whole file unless that file contains no blank lines.
>
> The second (with `RS="^$") will read the whole file but only with gawk 
> or another awk that supports multi-char RS. With a POSIX awk it'll 
> treat it as if you wrote `RS="^"` and only read the first 
> `^`-separated record.
>
>     Ed.
>
> On 6/11/2021 9:06 AM, Peng Yu wrote:
> > Hi,
> >
> > Both of the following commands can read a whole input. Are they always
> > the same under all possible input? Is there one preferred over the
> > other?
> >
> > $ builtin printf '%s\n%s' abc 123 | awk.sh -e 'BEGIN { RS=""; getline;
> > print $0 }'
> > abc
> > 123
> > $ builtin printf '%s\n%s\n' abc 123 | awk.sh -e 'BEGIN { RS="^$";
> > getline; print $0 }'
> > abc
> > 123