suggestion for new option: --block-break

[Cook, Malcolm]

I sometimes process files where I would like to be able to allow block boundaries to only occur at rows where “—block-breaks” occur.

 

I would like to be able to define such breaks as a perl _expression_, evaluated for each line, whose value must be different from the prior line for that line to be the beginning of a new block.

 

The _expression_ should be able to refer to columns either by number or by –header name.

 

For example, I have a program to emits a graph for every protein, where every line is residue of the protein, and there is a column, proteinID, whose value changes when the protein changes which I would like to call as follows:

 

parallel -j 40 –cat –block 10K --block-breaks proteinID

 

In the meantime I suppose a workaround is to preprocess the input and insert fake –recstart wherever the column changes value.

 

Other workaround welcome….

 

Cheers,

 

Malcolm Cook