du just uses the fts API, so if you want something directly equivalent (omitting options and error handling) it was only barely too long to post: http://pastie.

du just uses the fts API, so if you want something directly equivalent (omitting options and error handling) it was only barely too long to post: http://pastie.org/8315296 http://pastie.org/8315296 Compared to the equivalent find, code #1 is much faster in this completely scientific best of several runs: $ time (find OSS/llvm -type f -or -type l | wc -l) real 0m4.681s $ time du -d0 OSS/llvm real 0m4.863s $ time ./fts OSS/llvm real 0m0.559s Ostensibly because of the lack of stat calls. On the other hand the second paste and find with no arguments are equivalent. edit: screwed up benchmarks