walk and sor

This repository contains walk and sor, two utility programs that collectively replace find. walk recursively walks the directories specified on the command line (or the current directory, if none is specified), printing each file path. sor (“shell or”) reads file paths from standard input; for each path, it evaluates its arguments as Bash snippets, passing the path as an argument to each and printing the path if any snippet exits with status 0. For example, instead of saying

find . -type f -name \*foo\*

you can say

walk | grep foo | sor 'test -f'

If your filenames might contain newlines, you can say

walk -0 | grep -z foo | sor -0 'test -f'

Performance

By avoiding syscalls, walk achieves substantially better performance than find. A microbenchmark –

$ time find /usr >/dev/null

real    0m3.542s
user    0m0.880s
sys     0m2.646s
$ time walk /usr >/dev/null

real    0m2.311s
user    0m0.370s
sys     0m1.926s

– shows walk executing nearly 40% faster on a local file system with a hot cache. Performance on network file systems should be even better. On the other hand, find implements its predicates in-process, making them orders of magnitude faster than sor:

$ time find /usr -type f >/dev/null

real    0m3.464s
user    0m0.831s
sys     0m2.615s
$ time walk /usr | sor 'test -f' >/dev/null

real    7m40.127s
user    1m47.818s
sys     2m48.595s

History

walk and sor were originally written for Plan 9 from Bell Labs by Dan Cross. The original source is available.

Disclaimer

This is not an official Google product.