Re: GNU Parallel Bug Reports --header and --colsep parsing is aberrant when used without arguments

[Ole Tange]

On Sat, Jul 1, 2017 at 1:26 AM, Coby Viner <address@hidden> wrote:

> --header and --colsep parsing is aberrant when used without arguments.

First: Thanks for an error report that is very easy to understand. I
wish all error reports where as well written as this.

> Error example:
>
> Failing case 1:
>
> address@hidden:~] parallel --dry-run -j 1 --header --colsep '\t' "echo
> f1={f-1} f2={f2}" :::: <(perl -e 'printf "f-1\tf2\nA\tB\nC\tD\n"')
> \t echo f1=A f2=B
> \t echo f1=C f2=D

Here you are giving --header the argument of '--colsep'. So the equivalent is:

parallel --header '--colsep' --dry-run -j 1 '\t' "echo f1={f-1}
f2={f2}" :::: <(perl -e 'printf "f-1\tf2\nA\tB\nC\tD\n"')

--header always takes an argument and you are giving it one (albeit a
weird one).

> Failing case 2:
>
> address@hidden:~] parallel --dry-run -j 1 --header '.*\n' --colsep "echo
> f1={f-1} f2={f2}" :::: <(perl -e 'printf "f-1\tf2\nA\tB\nC\tD\n"')

Here you give --colsep the argument "echo f1={f-1} f2={f2}". This is
also a pretty weird argument to give --colsep.

In both cases I do not see a way to detect this: You _should_ be able
to give pretty weird input to both --colsep and --header if your data
requires this.

> Description:
>
> It appears that --header and --colsep when used with their default arguments
> can produce inconsistent results, if an argument is provided to only one of
> the two parameters. The result is counter-intuitive.

There is no default argument - they _always_ take an argument.

/Ole