zsh-smartcache

March 17, 2026 ยท View on GitHub

A Zsh plugin to cache command output to boost shell startup.

What it does

It basically has the same functionality as evalcache, except that

  • It will automatically update the cache, compile it, then inform you, while evalcache will never update the cache until you clear them. This operation is done in the background, so it has no effect on the satrtup time.
  • It also supports caching completions.

Benchmark

Here are some benchmark results. (CPU: Ryzen 3700X)

Benchmarked by hyperfine 'zsh -ic exit' and comparing the differences.

commandversionraw evalzsh-smartcacheevalcache
rbenv init1.2.0~48ms~23.5ms~23.5ms
hub alias2.14.2~2.5ms~1.5ms~1.5ms
scmpuff init0.5.0~2.5ms~2ms~2ms

Some changes from evalcache's results:

  • Only the subsequent runs are recorded. The first run has a fixed extra cost (~1ms).
  • Speedup of rbenv init is much lower, since the command output now includes rbenv calls, which are super slow.
  • hub alias and scmpuff init are superfast now.

Usage

Eval

eval "$(rbenv init -)"
# change to
smartcache eval rbenv init -

Completion

rustup completions zsh > ~/.zfunc/_rustup
fpath+=~/.zfunc
# change to
smartcache comp rustup completions zsh

Configuration

  • ZSH_SMARTCACHE_DIR: cache files storage, default to ${XDG_CACHE_HOME:-$HOME/.cache}/zsh-smartcache.