Re: [PATCH] bin/stdc: Improve output formatting

[Alejandro Colomar <alx.manpages@gmail.com>]

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Hi Oskari,

On 4/15/23 09:21, Oskari Pirhonen wrote:
> Hi Alex,
> 
> On Fri, Apr 14, 2023 at 13:26:59 +0200, Alejandro Colomar wrote:
>> Hi Oskari,
>>
>> On 4/14/23 05:19, Oskari Pirhonen wrote:
>>> Remove leading whitespace and collapse multi-line declarations into a
>>> single line using (g)awk.
>>
>> I can't reak awk(1) :(
>>
> 
> Awww man, but I even left the optional semicolons in...

:-)

> 
>> But I like the idea.  I implemented the same using sed(1) after your
>> suggestion.  Does the below patch look good to you?
>>
> 
> I actually had an earlier version with sed(1), but it used
> looping/branching to handle the multi-line bits, so I figured it was a
> bit ugly and didn't send it. I didn't think to try `-z`.
> 
> It seems to do the same thing, so LGTM.

Good.

> 
>> Cheers,
>> Alex
>>
>> P.S.: I forgot about writing a man page.  I'll start now.
>>
> 
> I was about to say "and license file and appropriate blurb" but then I
> saw your commit. I've got some suggestions for the man page, so I'll
> send some patches sometime soon.

Sure, please!

> 
> - Oskari
> 
> 
> Since you said you can't read awk, then just to satisfy your curiosity,

Thanks!

> here's what was going on:
> 
>     BEGIN {
>         RS = ";\n"
>         ORS = RS
>     }
> 
> This block is run at the start before any records are processed.
> 
> The default Record Separator is "\n", but here we set it to ";\n". In
> (g)awk, a value of `RS` that is >1 char is actually a regex, but we only
> need to match a literal string. The Output Record Separator is by
> default also "\n".
> 
>     {
>         gsub(/\n/, " ")
>         sub(/^ +/, "")
>         gsub(/ +/, " ")
>         print
>     }
> 
> This block is run on all records, since it doesn't have any patterns for
> contitional execution attached to it.
> 
> `gsub()` does an in-place global regex replace on a string, similar to
> the `s/regex/replace/g` you're familiar with. It takes an optional third
> arg, but if it's left out then it has an implicit `$0` which means the
> entire current record. `sub()` is like `gsub()`, but only does the first
> match, similar to `s/regex/replace/`.
> 
> `print`, without any args, prints the current record followed by `ORS`.
> This was set earlier because the `RS` is consumed from the input as it
> is being processed record by record, but we want to keep the output
> looking intact.
> 
> Hopefully not so bad after all.

Meh, I'll need some time to get used to it, I guess :)

> Awk is pretty nice IMO (and gawk in
> particular), and I would recommend checking it out if you find yourself
> borded one day :)

So far, I've almost always found one way or another with more specific
commands.  The only case I find awk(1) interesting is for processing
columns; it's quite good at that (e.g., for printing column sum totals).
The other alternative I can think of is pee(1), and process each column
separately, which might be more readable (for me).  But I might give it
a try some day.  :)

For now, awk(1) is only for `awk '{print $3}'` to me.

Cheers,
Alex

-- 
<http://www.alejandro-colomar.es/>
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