DEV Community: Jonas B. R.

How To Set Up History-Based Autocompletion in Zsh

Jonas B. R. — Wed, 28 Jul 2021 10:27:40 +0000

Yes, Oh My Zsh is awesome! That’s the first thing I installed when I switched from Bash to Zsh and I used it for a few years.

Past that time, I realized that in my daily use, the only features I was taking advantage was:

Autocompletion and history-based autocompletion using the arrow keys.
The fancy multi-line and colorful user prompt showing the working directory, and the switching color after the fail/success of the previous command execution.
The git repository info at the user prompt.
The z command, provided by the ZSH-z plugin.

I couldn’t help myself but thinking that the Oh My Zsh framework was much more than I needed. I decided to remove Oh My Zsh and reset Zsh from scratch, so I could configure and install only the features I needed.

This is a four-part post series explaining how to set up those features on a fresh new Zsh installation:

Customize Zsh Pt.1 - Autocompletion 👈

Customize Zsh Pt.2 - User Prompt

Customize Zsh Pt.3 - Git Info

Customize Zsh Pt.4 - ZSH-z Plugin

Autocompletion

Zsh has a powerful completion system built-in by default. You need to load and initialize to take advantage of it. There is a lot to learn about it if you feel like going deeper but this post’s objectives are:

To enable the standard autocompletion.
To set up history-based autocompletion.

How to Set Up

After a Zsh fresh install it runs a helper for the first time you log into the shell:



This is the Z Shell configuration function for new users,
zsh-newuser-install.
You are seeing this message because you have no zsh startup files
(the files .zshenv, .zprofile, .zshrc, .zlogin in the directory
~).  This function can help you with a few settings that should
make your use of the shell easier.

You can:

(q)  Quit and do nothing.  The function will be run again next time.

(0)  Exit, creating the file ~/.zshrc containing just a comment.
     That will prevent this function being run again.

(1)  Continue to the main menu.

--- Type one of the keys in parentheses ---

Avoid using the helper and apply the settings inside the .zshrc file, so:

Type 0 to exit the Zsh helper creating a blank .zshrc file in your $HOME directory.
To load and initialize the Zsh completion system, open the .zshrc file in your code editor and add the following line at the top of the file:



# AUTOCOMPLETION

# initialize autocompletion
autoload -U compinit && compinit

(Learn more: man zshcompsys and go to Use of compinit)

To allow history-based autocompletion, first, apply some configurations to improve Zsh’s history management by adding the following lines to the .zshrc file:



# history setup
setopt SHARE_HISTORY
HISTFILE=$HOME/.zhistory
SAVEHIST=1000
HISTSIZE=999
setopt HIST_EXPIRE_DUPS_FIRST

(Read options and parameters descriptions: man zshoptions and man zshparam)

With Zsh history set, create key bindings to use up and down arrow keys to navigate history for the provided command:



# autocompletion using arrow keys (based on history)
bindkey '\e[A' history-search-backward
bindkey '\e[B' history-search-forward

The code above assumes that [A is the value your terminal emulator sends for the keyboard up arrow, and that [B is the value for the keyboard down arrow.

You can double check by pressing <Ctrl> + v and <up-arrow> in your Zsh prompt, see more here.

(Learn more: man zshzle and go to ZLE BUILTINS for key bindings, and go to history-search-.)

Source the .zshrc file again, in the Zsh shell type:



source ~/.zshrc

Autocompletion is ready to go!

The final .zshrc file must look like this:



# AUTOCOMPLETION

# initialize autocompletion
autoload -U compinit
compinit

# history setup
setopt APPEND_HISTORY
setopt SHARE_HISTORY
HISTFILE=$HOME/.zhistory
SAVEHIST=1000
HISTSIZE=999
setopt HIST_EXPIRE_DUPS_FIRST
setopt EXTENDED_HISTORY

# autocompletion using arrow keys (based on history)
bindkey '\e[A' history-search-backward
bindkey '\e[B' history-search-forward

# GENERAL

# (bonus: Disable sound errors in Zsh)

# never beep
setopt NO_BEEP

With those simple steps autocompletion is ready and your Zsh shell is becoming more powerful.

Part 2 explores how to apply a simple configuration to improve the user prompt.

Customize Zsh Pt.2 - User Prompt

Useful links & references:

Zsh Documentation (man -k zsh to list each Zsh man page section)
key bindings table?
A Guide to the Zsh Completion With Examples

Footnotes:

This post appeared first at alldrops.info.
Follow me on Twitter to get more posts like this and other quick tips in your feed.
If you have any doubts or tips about this post, I’d appreciate knowing and discussing it in the comments section.
As English is not my native language, I apologize for the errors. Corrections are welcome.
Big thanks 🙌 to Eric Nielsen for pointing out some improvements in Zsh history settings.

How to Visualize Tabs in Vim

Jonas B. R. — Mon, 12 Jul 2021 14:59:43 +0000

(This is an excerpt taken from the post: Tabs & Spaces in Vim: How to Make Conscious Use of Both)

It will be presented two ways to visualize Tabs in Vim.

Searching for the Tab Character

A quick way to visualize whether there is a Tab character is by searching for it using Vim’s search-commands:

In NORMAL mode, type /\t and hit <Enter>. It will search for the Tab character (\t) and highlight the results.

Although it may be good for a quick check, if you need persistent Tabs visibility plus the ability to use the search-commands for other purposes, you might need another solution.

Activating `list` Mode

Vim’s list mode displays on screen unprintable characters (<Tab>, EOF, EOL, etc…) with strings defined by the listchars option.

By default, it will display ^I for a Tab character but this default representation breaks screen alignment so, the suggestion is to set a string representation to be used for the Tab character:

In NORMAL mode, type :set listchars=tab:▷▷⋮ or add set listchars=tab:▷▷⋮ to your .vimrc file.

The command above defines the strings that Vim will display (▷▷⋮) for a Tab character. Vim’s behavior is to repeat or omit the second character (▷), which means:

A Tab character on a file that the indentation is set to occupy two screen spaces, will display ▷⋮.

A Tab character on a file that the indentation is set to occupy four screen spaces, will display ▷▷▷⋮.

Toggle list mode by typing :set invlist in NORMAL mode.

Extra: Create a Mapping to Toggle list Mode Quickly

Add the following line to your .vimrc file:



noremap <Leader><Tab><Tab> :set invlist<CR>

(You may substitute <Leader><Tab><Tab> as you wish. If you’d like to know more about Vim mappings, please check this post.)

Check the full post about Tabs & Spaces in Vim to know more.

Do you have any other tip about visualizing Tabs in Vim? Please leave a comment!

Thanks for reading 🙌 !

To `git` or Not To `git` a Vim Session ?

Jonas B. R. — Tue, 19 Jan 2021 17:15:15 +0000

(This is an excerpt taken from the post: Vim Sessions - Plus: A custom command to save the session, the files, and then exit.)

Should you commit the session files created, to your project’s repository? If the project will be touched by more than one person, that’s something to be discussed with the other part(s).

My suggestion on that, based on the 2 workflows presented before (here), is:

Add Sessions.vim to your project's .gitignore file. - Since this auto-created file is now more related to your personal workflow on the project, it could bring more pain than help if committed to the project's repo.
Commit PriceUpdate.vim (example) to the project's repository.- If you create a custom session file to help quick maintenance on a stable project, it may be worth sharing with others since it could help anyone to dive in and make specific work without searching for files and content inside the project.

Check the full post about Vim Sessions to know more.

Do you have any other tip or strategy about Vim Sessions? Please leave a comment!

Thanks for reading 🙌 !

DEV Community: Jonas B. R.

How To Set Up History-Based Autocompletion in Zsh

Autocompletion

How to Set Up

Next:

Customize Zsh Pt.2 - User Prompt

Useful links & references:

Footnotes:

How to Visualize Tabs in Vim

Searching for the Tab Character

Activating list Mode

Extra: Create a Mapping to Toggle list Mode Quickly

To `git` or Not To `git` a Vim Session ?

Activating `list` Mode