How to diff file names in two directories (without writing to intermediate files)?

Question

I am trying to do something along the lines of:

diff `ls -1a ./dir1` `ls -1a ./dir2`

But that doesn't work for obvious reasons. Is there a better way of achieving this (in 1 line), than this?

ls -1a ./dir1 > lsdir1
ls -1a ./dir2 > lsdir2
diff lsdir1 lsdir2

Thanks

Answer 1

You were close. In bash you want process substitution, not command substitution:

diff <(ls -1a ./dir1) <(ls -1a ./dir2)

Answer 2

diff -rq dir1 dir2

using the -r option, walk entire directory trees, recursively checking differences between subdirectories and files that occur at comparable points in each tree. The trick is to use the -q option to suppress line-by-line comparisons