Re: gnu parallel

[Ole Tange]

Hi Ambrose.

Please use parallel@gnu.org for support (unless you are interested in
hiring me for support).

You should read the man page about --colsep and --xapply.

If this does not answer your question, feel free to post on the mailing list.


/Ole


On Wed, Mar 27, 2013 at 4:20 AM, Ambrose Kofi Laing <aklaing@gmail.com> wrote:
> Dear Ole,
>
> I have recently discovered Gnu Parallel, and I have a use case which I have
> not seen addressed in the documentation:
>
> Suppose I have a file like this:
>
> VeryLongNameA A
> VeryLongNameD D
> VeryLongNameM M
>
> etc.
>
> [Note: this is a case where there is no VeryLongNameB B pair, and so I just
> have to list what I actually do have in a file.  There is no pattern like a
> for all values in set 1, and for all values in set 2.
> Moreover, I also don't want VeryLongNameA to pair with D or M.]
>
> I want to do substitutions and {} will get the full line including the space
> (I believe).  What I need is something like (I'm making up a new syntax for
> this question) {&1} and {&2} where for a given line {&1} will be
> "VeryLongNameA" and {&2} will be "A".  And when we read the next line, then
> they will change to VeryLongNameD and D respectively, and so on.  Ideally
> the syntax would work  for many columns not just two.
>
> Note that the pattern is not regular enough that I can use your current
> meaning of {1} and {2} which I believe are for generating something like a
> cross product where {1} ranges over a certain set, and {2} ranges over a
> different set and you get all the possible combinations / pairs.
>
> The actual command I want it to expand to is something similar to:
>
> run_my_command VeryLongNameA.jpg < A.gif > A.log
>
> and I wanted to write something like
>
> run_my_command {&1}.jpg < {&2}.gif > {&2}.log
>
> or something like that.  Is this feature supported (with a different
> syntax)?
>
> Secondly if it is not supported, I have tried just writing the arguments
> above onto each line of the input file like so:
>
> VeryLongNameA.jpg < A.gif > A.log
> VeryLongNameD.jpg < D.gif > D.log
> ...
>
> And then my command is simply: run_my_command {}
>
> That is not working for some reason.  Is it obvious to you why that would
> not work?  I'm thinking it might have something to do with putting the
> redirect commands into the file.
>
> Thanks, I'd appreciate any help you can give,
>
> Ambrose
>
>