async-shell.el - Manage Shell Commands with Buffers

This package allows running a shell command in a buffer and provides conveniences for creating and managing these buffers. This is essentially an alternative to the built in compile command.

(Sorry about the dithering in the screenshots. It’s something that Github is doing and I’m not totally sure why.)

Screenshots

async-launch-shell starts a new buffer with a command read from the minibuffer.

Once you have an async-shell buffer, you can rerun the command by calling revert-buffer.

Pinning a line number (<async-shell-menu> p): When working on code, I often find it useful to pin the output to a certain line, so that I don’t have to scroll and find a particular location every time I rerun a command.

Re-run on save (<async-shell-menu> r): Enabling Reload on save will re-run the command in that buffer every time a file is saved. I find this incredibly useful for debugging code.

Org Babel

You can also create async-shell buffers from org-babel.

#+begin_src async-shell :name gif :results silent
name="babel"
ffmpeg -y -i ~/Desktop/$name.mov \
       -pix_fmt rgb24 -r 10 \
       pictures/$name.gif

gifsicle -O3 pictures/$name.gif -o pictures/$name.gif
#+end_src

This is useful for keeping track of and executing complex commands that you need to execute for different projects. Many of my projects contain an org-file where I can write down different commands I execute on a regular basis and add documentation explaining what they do. This means that I never have to search back through my command history to find a particular command, and makes editing commands trivial.

Additionally, async-shell babel blocks support specifying tramp directories. If I wanted to run the above command on some server, I could write:

#+begin_src async-shell :name gif :results silent :dir /ssh:sgpthomas@my.server.com:some/path
name="reload-on-save"
ffmpeg -y -i ~/Desktop/$name.mov \
       -pix_fmt rgb8 -r 10 \
       pictures/$name.gif

gifsicle -O3 pictures/$name.gif -o pictures/$name.gif
#+end_src

org-babel configuration

To support async-shell blocks, all you need to do is add (async-shell . t) to your 'org-babel-load-languages.

(org-babel-do-load-languages
 'org-babel-load-languages
 '((async-shell . t)
   ...))