runtimeterror/content/posts/cat-file-without-comments/index.md

title	date	description	featured	draft	toc	usePageBundles	codeLineNumbers	series	tags	comments
Cat a File Without Comments	2023-02-22	A quick trick to strip out the comments when viewing the contents of a file.	false	false	true	true	false	Tips	linux shell regex	true

It's super handy when a Linux config file is loaded with comments to tell you precisely how to configure the thing, but all those comments can really get in the way when you're trying to review the current configuration.

Next time, instead of scrolling through page after page of lengthy embedded explanations, just use:

egrep -v "^\s*(#|$)" $filename # [tl! .cmd]

For added usefulness, I alias this command to ccat (which my brain interprets as "commentless cat") in my ~/.zshrc:

alias ccat='egrep -v "^\s*(#|$)"'

Now instead of viewing all 75 lines of a mostly-default Vagrantfile, I just see the 7 that matter:

wc -l Vagrantfile # [tl! .cmd]
75 Vagrantfile # [tl! .nocopy]

ccat Vagrantfile # [tl! .cmd]
Vagrant.configure("2") do |config| # [tl! .nocopy:start]
  config.vm.box = "oopsme/windows11-22h2"
  config.vm.provider :libvirt do |libvirt|
    libvirt.cpus = 4
    libvirt.memory = 4096
  end
end # [tl! .nocopy:end]

ccat Vagrantfile | wc -l # [tl! .cmd]
7 # [tl! .nocopy]

Nice!