this post was submitted on 11 Jul 2023
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commandline

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One of my favorite command line tips: you can add 'comments' full of keywords to shell commands, which makes searching your command history easier.

> obscure-cmd --with-weird-flags -Qdt # searchable comment keywords

Presumably you're using something like fzf for history search, but this is still useful without it.

This is especially useful for cli tools with obscure names/flags, or when you can't remember where a particular log file is.


Some examples from my history:

tail awesomewm logs:

tail -f ~/.cache/awesome/logs -n 2000 # tail follow log awesomewm

fix linux clock drift:

sudo ntpd -qg && sudo hwclock --systohc # fix linux clock time drift

copy ngrok public url to clipboard:

curl -s http://localhost:4040/api/tunnels | jq ".tunnels[0].public_url" | tr -d '"' | tr -d '\n' | xclip -selection clipboard -i # fetch ngrok url uri, copy to clipboard

sign ssh and gpg, then refresh the emacs keychain env:

keychain --agents gpg,ssh --eval id_rsa <some-gpg-id> && emacsclient -e '(keychain-refresh-environment)' # sign ssh,gpg password, refresh emacs env

Another gpg one:

git config commit.gpgsign false # disable gpg signing for this repo

Pacman/pamac commands, like listing orphaned packages:

pacman -Qdt # list orphans
pamac list -o # list orphans

xprop - super useful for debugging window management, for some reason i can never remember what it's called:

xprop # mouse click window x11 linux describe info client helper whateveritscalled

Some helpers from my clawe project:

bb --config ~/russmatney/clawe/bb.edn -x clawe.sxhkd.bindings/reset-bindings # reset sxhkd bindings
bb --config ~/russmatney/clawe/bb.edn -x clawe.restart/reload # reload clawe

Aliases come to mind as well - in some cases that might be a better fit. I like this because it's so low-lift.

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[–] gamma 6 points 1 year ago

One big caveat here: In Zsh (and maybe other shells) you might have to explictly enable comments in interactive sessions:

setopt interactivecomments
[–] howarddo 5 points 1 year ago* (last edited 1 year ago) (2 children)

Nice tip, I will start doing it from now on. I recommend Atuin to keep and sync the shell history, although I don't like its default bindings.

[–] russmatney 4 points 1 year ago (1 children)

Interesting, syncing history across machines is pretty cool. While writing this I went looking for my yabai logs helper as an example, but of course, it's on my other machine, haha

Security (sharing secrets from that history) comes to mind, so I feel compelled to mention that adding a space before a command is a pattern for preventing it from being stored in history, though I think I had to opt-in to that in my zsh config: setopt HIST_IGNORE_SPACE

[–] howarddo 2 points 1 year ago (1 children)

Oh, I didn't know that, thanks! Do you know any quick way to search and delete password contained commands in the history?

[–] russmatney 2 points 1 year ago (1 children)

The simple and probably better answer is that you can just vim ~/.zsh_history and search for/delete the lines directly.

Buuuuut! I wrote zsh command for doing exactly that a few years ago (in my dotfiles, but i've pasted it below as well):

################################################################################
# Delete from history via fzf
################################################################################

# https://superuser.com/questions/1316668/zsh-bash-delete-specific-lines-from-history
function delete-command () {
  # Prevent the specified history line from being saved.
  local HISTORY_IGNORE="${(b)$(fc -ln $1 $1)}"

  # Write out the history to file, excluding lines that match `$HISTORY_IGNORE`.
  fc -W

  # Dispose of the current history and read the new history from file.
  fc -p "$HISTFILE" "$HISTSIZE" "$SAVEHIST"

  # TA-DA!
  print "Deleted '$HISTORY_IGNORE' from history."
}

function pick_from_history () {
  history | fzf --tac --tiebreak=index | perl -ne 'm/^\s*([0-9]+)/ and print "$1"'
}

function delete_from_history () {
  delete-command "$(pick_from_history)"
}

It uses fzf to filter and select a command to delete. It's cool but might be slow b/c you're doing it one at a time. It also may depend on your zsh config (i think the history command i'm using there comes from ohmyzsh, but i'm not too sure).

[–] howarddo 2 points 1 year ago

I tried it, it's nice, thank you man! I'm on zsh, so I have to add history 0 in pick_from_history tho. It would be nicer if it allows continuous deletion and not need to rerun every time. Btw, even when I delete it locally it wouldn't delete already synced history on Atuin, I guess I'll take a look at that later.

[–] russmatney 2 points 1 year ago

After further inspection, Atuin looks sweet! Looks like they encrypt your history and offer finer-grained search (like dates and things). Great rec, thanks for sharing!

[–] tatterdemalion 4 points 1 year ago (2 children)

Good idea.

Another tool in the same vein is tldr:

$ tldr tar

  tar

  Archiving utility.
  Often combined with a compression method, such as gzip or bzip2.
  More information: https://www.gnu.org/software/tar.

  - [c]reate an archive and write it to a [f]ile:
    tar cf path/to/target.tar path/to/file1 path/to/file2 ...

  - [c]reate a g[z]ipped archive and write it to a [f]ile:
    tar czf path/to/target.tar.gz path/to/file1 path/to/file2 ...

  - [c]reate a g[z]ipped archive from a directory using relative paths:
    tar czf path/to/target.tar.gz --directory=path/to/directory .

  - E[x]tract a (compressed) archive [f]ile into the current directory [v]erbosely:
    tar xvf path/to/source.tar[.gz|.bz2|.xz]

  - E[x]tract a (compressed) archive [f]ile into the target directory:
    tar xf path/to/source.tar[.gz|.bz2|.xz] --directory=path/to/directory

  - [c]reate a compressed archive and write it to a [f]ile, using [a]rchive suffix to determine the compression program:
    tar caf path/to/target.tar.xz path/to/file1 path/to/file2 ...

  - Lis[t] the contents of a tar [f]ile [v]erbosely:
    tar tvf path/to/source.tar

  - E[x]tract files matching a pattern from an archive [f]ile:
    tar xf path/to/source.tar --wildcards "*.html"

[–] verstra 3 points 1 year ago (1 children)
[–] russmatney 1 points 1 year ago

Nice. Classic rust reimplementation.

[–] russmatney 2 points 1 year ago

Yesssss tldr is awesome!

[–] attn_dfct_dev 4 points 1 year ago

Great tip. This is simple enough to use on the daily.