Feature Request / Discussion: `cut` to several files

[Erik Brinkman]

It'd be nice if cut allowed writing to several files. I'm not sure what the
appropriate syntax for something like this would be, but I could see a
command looking something like:

cut -f 1,2 filename1 -f 3-5 filename2

or maybe

cut -f 1,2:filename1:3-5:filename2

I don't think the first syntax is posix, and it's definitely not backwards
compatible. The second might work, but is pretty ugly. I couldn't find
anything related to this in the archive or in the rejected feature
requests. Some alternatives with downsides:

   - Save the buffer and use cut repeatedly on that. The downside is it
   requires the buffer to be saved.
   - I managed to throw together an awk script that could be tailored to do
   similar things. This writes column 1 to file 1, etc for all of the listed
   files:

   awk 'BEGIN { NUM = ARGC; if ( ARGC > 2 ) ARGC = 2 } { for ( I = 2; I <
   NUM; ++I) { print $(I - 1) > ARGV[I] } }' input_file column_1 column_2

   The nice part is that this works with subprocesses wiithout saving
   entire intermediate buffers:
   paste <(seq 1 10) <(seq 11 20) | awk 'BEGIN { NUM = ARGC; if ( ARGC > 2
   ) ARGC = 2 } { for ( I = 2; I < NUM; ++I) { print $(I - 1) > ARGV[I] } }' -
   >(paste -sd+ | bc) >(paste -sd+ | bc)

   However, this is ugly, pretty manual, and doesn't support ranges very
   easily.

It seems plausible that cut source could be modified to store a field /
character list for each file, open up all of them, and write characters /
fields out on the fly as it normally does with stdout. I'm happy to
implement this myself and patch, but I'm uncertain if the coreutils team
views this as an appropriate addition, and if so, what a proper syntax
would look like. It seems like since this is modifying the field spec of
cut, it could potentially have ramifications for other field specifications
in coreutils, although I can't think of any the relate to writing, so it
may not matter.

Thanks,
Erik