Format code with VIM using external commands

Question

I know that using VIM I can format C++ code just using

gg=G

Now I have to format 30 files, so doing it by hand becomes tedious. I had a look how to do it passing external commands to VIM, so I tried

vim -c gg=G -c wq file.cpp

but it does not work.

Can you give me a hint?

Thanks

Answer 1

Why not load all the files up in buffers and use bufdo to execute the command on all of them at one time?

:bufdo "execute normal gg=G"

Answer 2

Change -c gg=G to -c 'normal! gg=G'. -c switch accepts only ex mode commands, gg=G are two normal mode commands.