Re: [Bug-datamash] Output field separator switch?

[Assaf Gordon]

Hello,

On 30/08/17 06:06 PM, Dave Myron wrote:
> I'm late to the game discovering GNU datamash but it's fantastic! 

Thank you for your kind words.

> One thing I've found strange is that passing in the field separator also
> impacts the output. 
> 
> For example, with a CSV file I, obviously, give -t, but that also causes
> datamash to print its output with a comma separator. This is surprising
> to me.

Indeed, this is the default behavior.
It is modeled after many other common unix utilities
which assume the input and output are of the same 'type'
(that is, CSV, tab-separated, white-space separated, etc.).

For example, if one does:

  $ cut -d: -f1,6 /etc/passwd
  root:/root
  daemon:/usr/sbin

The "-d:" parameters sets both the input and output delimiters to ":".

However, I see GNU cut has an additional parameter "--output-delimiter",
exactly for cases like yours:

  $ cut -d: -f1,6 --output-delimiter=, /etc/passwd
  root,/root
  daemon,/usr/sbin

I can add the same option to datamash, so it'll be:

   datamash -t, --output-delimiter="\t" [...]

But for an immediate solution, you can either use 'column' as you've
written (if you want white-space separated and aligned output),
or use 'sed' or 'tr' to replace all commas with a single tab:

   datamash -t, [....] | sed 's/,/\t/g'
   datamash -t, [....] | tr , '\t'


I'll reply to this thread when the new option is ready in datamash.

regards,
 - assaf