Executing Vim commands in a shell script

Question

I am writing a Bash script that runs a command-line program (Gromacs), saves the results, modifies the input files, and then loops through the process again.

I am trying

Answer 1

Alternatives

Unless you really need special Vim capabilities, you're probably better off using non-interactive tools like sed, awk, or Perl / Python / Ruby / your favorite scripting language here.

That said, you can use Vim non-interactively:

Silent Batch Mode

For very simple text processing (i.e. using Vim like an enhanced 'sed' or 'awk', maybe just benefitting from the enhanced regular expressions in a :substitute command), use Ex-mode.

REM Windows
call vim -N -u NONE -n -es -S "commands.ex" "filespec"

Note: silent batch mode (:help -s-ex) messes up the Windows console, so you may have to do a cls to clean up after the Vim run.

# Unix
vim -T dumb --noplugin -n -es -S "commands.ex" "filespec"

Attention: Vim will hang waiting for input if the "commands.ex" file doesn't exist; better check beforehand for its existence! Alternatively, Vim can read the commands from stdin. You can also fill a new buffer with text read from stdin, and read commands from stderr if you use the - argument.

Full Automation

For more advanced processing involving multiple windows, and real automation of Vim (where you might interact with the user or leave Vim running to let the user take over), use:

vim -N -u NONE -n -c "set nomore" -S "commands.vim" "filespec"

Here's a summary of the used arguments:

-T dumb           Avoids errors in case the terminal detection goes wrong.
-N -u NONE        Do not load vimrc and plugins, alternatively:
--noplugin        Do not load plugins.
-n                No swapfile.
-es               Ex mode + silent batch mode -s-ex
                Attention: Must be given in that order!
-S ...            Source script.
-c 'set nomore'   Suppress the more-prompt when the screen is filled
                with messages or output to avoid blocking.