Today I tried to run these examples on (info "(coreutils) Paired and unpaired lines") it says: All examples below use the following two (pre-sorted) input files:
$ cat file1 $ cat file2 a 1 a A b 2 c C How about instead, something like echo a 1 > file1 echo b 2 >> file1 echo a A > file2 echo c C >> file2 That way the user could create the files themselves without much hassle. Just pipe that part of the page into the shell. You can even still have the cats after the creation. But please remember to just use one column.