Re: Use of --colsep without --header for multiple input files

[Coby Viner]

That's great—thanks so much!

-- Coby

On Sat, July 1, 2017 12:22 am, Ole Tange wrote:
> On Sat, Jul 1, 2017 at 1:56 AM, Coby Viner <cviner@cs.toronto.edu> wrote:
>
>> Is it possible to use --colsep with multiple input files, without having
>> to
>> manually prefix each files' header by a unique identifier for use in
>> conjunction with --header?
>
> Yes.
>
>> For example, it would be nice if with multiple files they could be
>> automatically labelled with a–z, with numerals still referring to their
>> columns (the reverse strikes me as better, but that would be
>> counter-intuitive given the present implementation).
>
> The current implementation numbers the total amount of columns. In
> your case {1}, {2}, {3} and {4}.
>
> Nice thing about this is that negative number and all --rpl strings
> starting with '{' work, too. Here we lowercase column 3 (second to
> last = -2):
>
> $ parallel --rpl '{lowercase} $_=lc($_)' --colsep '\t' "echo f1={1}
> f2={2} g1={-2 lowercase} g2={4}" :::: <(perl -e 'printf
> "f1\tf2\nA\tB\nC\tD\n"') :::: <(perl -e 'printf
> "g1\tg2\nE\tF\nG\tH\n"')
>
>> I would ideally like to be able to do the following:
>>
>> parallel --colsep "echo f1={a1} f2={a2} g1={b1} g2={b2}" :::: <(perl -e
>> 'printf "f1\tf2\nA\tB\nC\tD\n"') :::: <(perl -e 'printf
>> "g1\tg2\nE\tF\nG\tH\n"')
>>
>> Currently, the use of --colsep without --header for multiple files does
>> not
>> behave as I would have expected:
>>
>> parallel --colsep '\t' "echo f1={1} f2={2} g1={1} g2={2}" :::: <(perl -e
>> 'printf "f1\tf2\nA\tB\nC\tD\n"') :::: <(perl -e 'printf
>> "g1\tg2\nE\tF\nG\tH\n"')
>> f1=f1 f2=f2 g1=f1 g2=f2
>> f1=f1 f2=f2 g1=f1 g2=f2
>> f1=f1 f2=f2 g1=f1 g2=f2
>> f1=A f2=B g1=A g2=B
>> f1=A f2=B g1=A g2=B
>> f1=A f2=B g1=A g2=B
>> f1=C f2=D g1=C g2=D
>> f1=C f2=D g1=C g2=D
>> f1=C f2=D g1=C g2=D
>
> Try using {3} and {4}:
>
> parallel --colsep '\t' "echo f1={1} f2={2} g1={3} g2={4}" :::: <(perl
> -e 'printf "f1\tf2\nA\tB\nC\tD\n"') :::: <(perl -e 'printf
> "g1\tg2\nE\tF\nG\tH\n"')
>
> I have updated the man page:
>
> --colsep regexp
> -C regexp
> Column separator. The input will be treated as a table
> with regexp separating the columns. The n'th column can
> be access using {n} or {n.}. E.g. {3} is the 3rd column.
>
> If there are more input sources, each input source will
> be separated:
>
> parallel --colsep ',' echo {4} {3} {2} {1} ::: "A,B" :::
> "c,d"
>
> --colsep implies --trim rl, which can be overridden with
> --trim n.
>
> regexp is a Perl Regular _expression_:
> http://perldoc.perl.org/perlre.html
>
> /Ole
>