asdf-exec

README

asdf-exec

Experimental command to find and run executable used by asdf shims.

NOTE: This is not officially supported by asdf and requires to slightly patch the asdf code

Installation

I assume asdf is installed in ~/.asdf. If not, please change the commands accordingly.

First, grab the asdf-exec executable from the releases and put it in ~/.asdf/bin/private as asdf-exec

# for linux
wget https://github.com/danhper/asdf-exec/releases/download/v0.1.1/asdf-exec-linux-x64 -O ~/.asdf/bin/private/asdf-exec
# for macos
wget https://github.com/danhper/asdf-exec/releases/download/v0.1.1/asdf-exec-darwin-x64 -O ~/.asdf/bin/private/asdf-exec

# for both:
chmod +x ~/.asdf/bin/private/asdf-exec

Then, patch asdf reshim command code and regenerate all shims.

sed -i.bak -e 's|exec $(asdf_dir)/bin/asdf exec|exec $(asdf_dir)/bin/private/asdf-exec|' ~/.asdf/lib/commands/reshim.sh
rm ~/.asdf/shims/*
asdf reshim

Rationale

As asdf is growing in features and complexity, the logic to run a single command has become fairly involved and unfortunately quite slow. For example

$ time python --version
Python 3.7.2
0.19user 0.04system 0:00.16elapsed 142%CPU (0avgtext+0avgdata 4344maxresident)k
0inputs+0outputs (0major+25175minor)pagefaults 0swaps

While there are surely many things we could do better with bash to improve performance, tuning bash is quite tedious and error-prone.

I decided to give a native command a try. This would be called from shims and would take care of locating the correct version. Although this does results in quite a bit of duplication between the bash code and this one, it does give a speed improvement which might be worth it.

$ time python --version
Python 3.7.2
0.00user 0.00system 0:00.01elapsed 100%CPU (0avgtext+0avgdata 4096maxresident)k
0inputs+0outputs (0major+691minor)pagefaults 0swaps

This is still totally experimental and there are no plan to merge or use this into asdf for now, but please feel free to give it a try and let me know what you think.