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`walk` and `sor`
================
This repository contains `walk` and `sor`, two utility programs that
collectively replace [`find`][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'
[find]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/find.html
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.
[Dan Cross]: http://pub.gajendra.net/about
[Plan 9 from Bell Labs]: https://web.archive.org/web/20170601064029/http://plan9.bell-labs.com/plan9/index.html
[original source]: https://web.archive.org/web/http://plan9.bell-labs.com/sources/contrib/cross/
Disclaimer
----------
This is not an official Google product.
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