hello people, I saw this post
https://unix.stackexchange.com/questions/783990/merge-multiple-files-using-full-join-by-the-first-column/784240#784240 and just had fun writing the following solution but there is no way I'll create an account on stackexchange. feel free to reuse if you think it's helpful. <<% cat > 346_T1_A_deduped.bismark.cov_format 1_10525 95.2 1_10526 98.9690721649485 1_10542 80.8 1_10543 87.6288659793814 % <<% cat > 346_T1_B_deduped.bismark.cov_format 1_10525 95.7142857142857 1_10526 98.1132075471698 1_10542 78.5714285714286 1_10549 75.4716981132076 % raku -e ' say join ",", @*ARGS; my %data = @*ARGS.map: { $_ => %( .IO.lines.map: | *.words ) }; for keys set %data.values».keys -> \k { say join ",", k, @*ARGS.map: { %data{$_}{k} // "N/A" } } ' *mat 346_T1_A_deduped.bismark.cov_format,346_T1_B_deduped.bismark.cov_format 1_10526,98.9690721649485,98.1132075471698 1_10543,87.6288659793814,N/A 1_10525,95.2,95.7142857142857 1_10542,80.8,78.5714285714286 1_10549,N/A,75.4716981132076 HTH, regards -- Marc Chantreux Pôle CESAR (Calcul et services avancés à la recherche) Université de Strasbourg 14 rue René Descartes, BP 80010, 67084 STRASBOURG CEDEX 03.68.85.60.79