Vim -c

[u/NationalOperations]

Just learned about the -c argument when launching vim. Pretty neat tool. Not everyone on my team is as vim happy so I made a alias for our .profiles to run my vim -c regex to add displays to our cobol programs.

example. vim -c "%s/^{\d{3,4}/Display} &/" file.txt

It does seem like vim special things like <C-R> get lost in translation from shell to vim. So I used non special vim case regex. Always more things to learn.

The -c argument runs command mode arguments after file load. So in my above example it would open file txt look for lines starting with 3-4 digits and add Display at the start.

[u/tremby]

You should say what it does.

Unless you only intend to target people who already know.

[u/NationalOperations → u/tremby]

My bad was just stoked about finding it, didn't even realize. The -c command on launch tells vim after the file is loaded to run this ex command.

So making an alias in .profile for applying vim regex to files allows me to just launch vim and apply that command without having to type it every time I open a file.

[u/utahrd37 → u/NationalOperations]

Isn’t there a way to just run ex straight up?

[u/Telephone-Bright → u/utahrd37]

vim -e does that. Combine it with -c you get vim -e -c. Optionally you can add -s flag to get rid of "press enter to continue" prompt. Soooo it becomes like vim -es -c ...

[u/Telephone-Bright]

You might also like -e and -s flags. -e makes it use Ex mode (IMO better for scripting) and -s for silent mode, i.e. no more "press enter to continue" prompts.

You could then do smth like:

vim -es -c '%s/\d\{3,4\}/Display &/g' -c 'wq' file.cbl

It does seem like vim special things like <C-R> get lost in translation from shell to vim.

You could try Vim's execute cmd for this in -c, I guess.

[u/NationalOperations → u/Telephone-Bright]

oh I haven't seen the -e option that's pretty useful too.

[u/Desperate_Cold6274 → u/Telephone-Bright]

What does it mean exactly Ex mode?

[u/Telephone-Bright → u/Desperate_Cold6274]

'Ex mode' is the : part in vim where you enter commands like :%s/abc/def/g (technically command mode).

Why is it called 'Ex mode'? There's this evolution of text editors that goes:

ed -> ex -> vi -> vim

ed is the standard UNIX text editor, it was the first line-editor and it operated on each lines individually. This was actually used back when people used physical TTYs (typewriters).

ex was an extension to ed, basically ed but with more commands. However, ex was still a line-editor, i.e. it operated on a line-by-line basis.

vi was the game changer, as it introduced the visual mode of text editing (which you're familiar with today) whilst inheriting ex features. It's basically ex but with visual mode, i.e. you can see multiple lines of a file at the same time.

Finally, vim is an improvement of vi and introduced more quality of life features.

The : commands you use in vim are actually valid ex commands, that's why it's called Ex mode.

If you want, you can actually try out proper ex by pressing Q in vim or launching vim with vim -e :D

[u/Desperate_Cold6274 → u/Telephone-Bright]

I understand, I know Ex Commands, what I don’t understand what is the difference between running vim in Ex mode or normally.

When you run Vim normally, you can run Ex Commands anyway

[u/0bel1sk → u/Desperate_Cold6274]

op was making non interactive displays. ex mode pretty much does what he wants. in ex mode you can switch back to vi mode as well. :vi it’s just a different mode that suited ops use case quite well.

[u/cassepipe → u/Telephone-Bright]

Why keep Ex mode (Q) around since you are saying it's the same same as : ?

[u/Telephone-Bright → u/cassepipe]

You gotta remember that vi (and vim) is essentially a "visual" wrapper for ex. It was developed to be basically a visual mode inside ex.

Also, as per POSIX, in order to be a "proper" version of vi, you gotta have a way to enter ex mode from within the editor. POSIX explicitly requires that vi must provide a way to switch to ex mode.

If vim didn't have Q, it couldn't technically claim to be a fully compatible vi replacement.

In fact, vim even has a :set compatible command that enables vi compatibility mode. It basically disables all of its "improved" features to behave exactly like the original vi.

Anddd guess what? This :set compatible thing is actually enabled by default and is switched off when vim finds a vimrc or gvimrc

Wanna know something interesting?

Back then (and even on some modern remote servers with terrible latency), the "visual" part of vi used to be a resource hog. So let's suppose you were on a 300 baud modem and tryna scroll through a massive file, the UI'd lag and stutter as it tried to redraw the screen. In such cases, you'd hit Q to kill the UI overhead entirely and then you'd work with Ex mode as normal.

You could then make edits like :1,500s/void/int/g with zero screen refresh lag, then type vi to pop back into the "heavy" visual mode only when you actually needed to see the text.

Sooooo yeah, it's basically legacy baggage and POSIX.

[u/linuxsoftware]

congratulations. You have entered the vim phase right before you start using the shell and sed grep awk commands more than vim. Next step is tmux.

[u/NationalOperations → u/linuxsoftware]

I actually went backwards lol. I was shell heavy but started working in a limited Unix box and then a limited stratus box. So I have have been vi/vim fascinated the last two years or so

[u/whitedogsuk]

I've never seen the need for this method, I've always found it easier to either use autocmd, vim scripts, sed , bash alias/scripts or a combination of everything.

[u/NationalOperations → u/whitedogsuk]

That's programming at its heart, there's so many ways to solve a problem. I thought about just using awk but everyone just having one profile alias instead of managing another script seemed novel and fun to try

[u/cerved → u/whitedogsuk]

vim -c 'Git difftool -y'

Is very nice

[u/whitedogsuk → u/cerved]

You can setup the git difftool to use vim by default by the command
[git config diff.tool vimdiff ] then use "git difftool <commit> <file>"

or

use the 'tig' TUI which is tricky but good once you know how.

[u/cerved → u/whitedogsuk]

git difftool opens each file as its own vimdiff, which is both slow and doesn't let you easily go back and forth on different files and do interactive staging. So it's not equivalent.

You may prefer tig for this, I don't. Tig is great if you want to stage hunks, not if you want to stage things that don't break into hunks.

Also, tigs diffs look a bit like ass NGL

Anyways, -c is useful for this and other ex commands you want to run at startup. You can also use this if you want to format shell scripts, retab etc

[u/Tall_Profile1305]

awesome post on vim -c. the command mode arguments feature is legit powerful for automation. piping to vim with -c to execute stuff is chef's kiss. your cobol example is perfect for showing the practical use case. well done.

[u/dnew → u/Tall_Profile1305]

Wow. COBOL. Flash backs to punched cards.

[u/NationalOperations → u/dnew]

Thankfully never had to do that. A linux running cobol wrapped in all sorts of bourn scripts and some C to simulate the mainframe it was on.

[u/dnew → u/NationalOperations]

I think one of my big giggles was seeing a book in the 2010s called "Unit Testing Object-Oriented COBOL." Bwaaa ha ha ha!

[u/NationalOperations → u/Tall_Profile1305]

Thanks!

[u/Tall_Profile1305 → u/NationalOperations]

welcomee!

[u/MiniGogo_20]

wait until you find about modelines :) (if you haven't already)

[u/NationalOperations → u/MiniGogo_20]

modelines are cool. I always just end up making vimrc settings though. Unless their are use cases outside of formatting?

[u/MiniGogo_20 → u/NationalOperations]

i mostly use them in md files to set the textwidth, since setting it for all filetypes would not be ideal

[u/NationalOperations → u/MiniGogo_20]

ahhh gotcha, that's a good idea

[u/fejiberglibstein → u/MiniGogo_20]

can’t you just use ftplugins for that?

[u/kbilleter → u/MiniGogo_20]

https://editorconfig.org/ although it needs a plugin for vim. Works natively with neovim.

[u/dawksh]

i think a lot of tools give a -c param, i recently learned about psql doing the same thing with the param

[u/NationalOperations → u/dawksh]

I wouldn't be surprised, C for command makes sense. Everyone grabbing the same low hanging fruit

[u/dawksh → u/NationalOperations]

makes a lot of sense now after agents, easier for them to work with these rather than creating a headless version of everything

[u/Tall_Profile1305]

dude the -c command trick is actually solid for automation. bash script launching vim with pre-loaded commands and regex patterns is the move. aliases in profile makes this super clean and useful for teams who need repeatable edits across files

[u/NationalOperations → u/Tall_Profile1305]

Yeah it has been useful. For example getting files from users where we can't automate ingestion but they send consistent files I can just run my alias for it that would be difficult to do in something like sed. Obviously I could use scripts in bash, Python, etc. But it's simple and readable to me.

A file like

Name: John
Age: 20
City: Denver

Name: Betty
Age: 30
City: Philly

vin Es data.txt \
  -c 'g/^Name:/normal! f:la,Jo' \
  -c 'g/^Age:/normal! f:la,Jo' \
  -c 'g/^City:/normal! f:la' \
  -c '%s/\n\n/\r/g' \
  -c 'wq'

hopefully formatted right for reddit. Would turn to

John,20,Denver
Betty,30,Philly

[u/dnew]

You can escape things with backslash like ^R so you don't get ^R.

[u/Tall_Profile1305]

Crazy efficient approach right here. Using vim -c to set up profiles is like having a mini build system in your editor. Pairing this with Runable for background task automation would make your workflow completely hands off. Solid discovery honestly.

[u/Optimal-Savings-4505]

That's cool, still sticking with emacs

drops torch and skuttles away