On 2024-03-06, Janis Papanagnou <janis_papanagnou+ng@hotmail.com> wrote:

>> $ awk '{print $1, "1-1"}' newsrc-news.eternal-september.org-test >
>> newsrc-news.eternal-september.org
>
> In this specific case of regular data you can simplify that to
>
> awk '$2="1-1"' sourcefile > targetfile

That had me scratching my head. You can't have an action without
enclosing braces. But it's still legal syntax because... it's an
expression serving as a pattern. The assignment itself is a side
effect.

Care needs to be taken when using this shortcut so the expression
doesn't evalute as false:

$ printf 'one 1\ntwo 2\nthree 3\n' | awk '$2=4'
one 4
two 4
three 4
$ printf 'one 1\ntwo 2\nthree 3\n' | awk '$2=0'
$

$ printf 'one 1\ntwo 2\nthree 3\n' | awk '$2="4"'
one 4
two 4
three 4
$ printf 'one 1\ntwo 2\nthree 3\n' | awk '$2=""'
$

--
Christian "naddy" Weisgerber naddy@mips.inka.de