Leaf directories (Re: Why is find so slow)

[Larry Wall]

In article <26981 at mimsy.umd.edu> chris at mimsy.umd.edu (Chris Torek) writes:
: In article <F&0u96p2 at cs.psu.edu> flee at guardian.cs.psu.edu (Felix Lee) writes:
: >Leaf directories are directories with no subdirectories.  A leaf
: >directory has a link count <= 2.
: 
: It is easier than that (and harder than this, which leaves out error
: checking):
: 
: 	d = opendir(dir);
: 	fstat(dirfd(d), &st);
: 	nsubdirs = st.st_nlink - 2;
: 	while ((dp = readdir(d)) != NULL) {
: 		if (need_stat_anyway || nsubdirs > 0) {
: 			get_stat(dir, dp->d_name, &st);
: 			if (S_ISDIR(st.st_mode))
: 				nsubdirs--;
: 		}
: 		...
: 	}

If find is done this way, it would behoove us to sort subdirectories
before filenames in each directory so that nsubdirs goes to 0 as soon
as possible.

Larry Wall
lwall at jpl-devvax.jpl.nasa.gov