Speedier indentation of many files

Question

I recently needed to re-indent a large number of files. I used variations of:
find . -type f -exec vim -c "normal gg=GZZ" {} \;

Which worked well, but incredibly slowly (across several hundred files, some of which have thousands of lines).

Is there a faster way to have used vim for this? (note: I'm not asking the general question of how to do re-indenting, but only if there is a faster method in vim)

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Update: I attempted filbranden's answer and it was MUCH slower, but I don't think I was able to make a good apples to apples comparison, so it may not be fair to call it slower. My attempt using the args list never finished and I ended up killing it. It was progressing, but very slowly. I like having the args list approach in my toolbox; I'm sure it will be useful sometime.

For context, I ran this in git bash on Windows. The vim process was pretty steady at ~90 mb ram, but the system commit charge was really high at ~37 gb (which is abnormal on my 32 gb ram machine). I'm not a Windows memory expert, but I think that means it may have been swapping, which would certainly explain the slowness.

Answer 1

You can use a single instance of Vim to open all the files and then use :argdo (or one of the other similar batch commands) to operate on all the files.

Start by simply opening Vim, with no files:

$ vim

Then use :args to pass it the file list. You can actually use your find command, with back ticks:

:args `find . -type f`

Then run :argdo to re-indent them, and :w after done:

:argdo exe "norm gg=G" | w

That's all you need! You need to use :execute here to be able to run both the :normal and :w command, without :execute the :normal command would try to interpret | as a Normal-mode command.

An alternative is to use :set hidden, which allows you to change buffers without saving, and then writing all of them at the end, while quitting:

:set hidden
:argdo norm gg=G
:wqa