Tim Bray blogged about topfew, his Go implementation of a tool to replace the awk '{print $1}' access_log | sort | uniq -c | sort -rn | head -12 pipeline. This is a reimplementation of that tool in idiomatic stable Rust.

The initial Rust version was 2.9x faster than Tim's Go implementation; current main appears to be around 6.7x faster thanks to some additional optimizations. The Rust version currently has slightly fewer non-test SLOC than the Go version. Thanks to Thomas Andreas Jung for contributing substantial performance improvements.

Usage: tf [OPTIONS] --fields <FIELDS> <FILE>

Arguments:
  <FILE>  File to search

Options:
  -f, --fields <FIELDS>  Fields to use as part of the line's key
  -n, --num <NUM>        Top number of matches to show [default: 10]
  -e, --regex <REGEX>    Regular expression used to split lines into fields [default: "[ \\t]"]
  -h, --help             Print help

If you have the Rust toolchain installed, you can install it with cargo install topfew.