Possible Duplicate:
Linux: Compare Directory Structure Without Comparing Files
I am diff-ing two folder trees, but it takes a long time because it is diff-ing the files themselves. I just want to know what folders/files are in one tree and not the other.
What is the best way to do this?
Use find to list the files in each tree, sort them, then use diff or comm for comparison. The little-known comm command is a specialized file comparison tool that just distinguishes lines appearing only in the first file, lines appearing only in the second file and lines appearing in both files.
(cd /some/dir1 && find . | sort >/tmp/dir1.find)
(cd /where/dir2 && find . | sort >/tmp/dir2.find)
# Show the files that are in dir1 but not in dir2
comm -23 /tmp/dir1.find /tmp/dir2.find
# Show the files that are in dir2 but not in dir1
comm -13 /tmp/dir1.find /tmp/dir2.find
