Feature request: Fish-like autocompletion and autosuggestion

[seagle0128]

Hi, I like this project and use recently. I used Fish and ZSh. I'd like request some new features I missed very much: Fish-like autocompletion and autosuggestion. Some guys implemented in Zsh already. is it possible to implement in Bash? Thanks!

[nwinkler]

Can you please described what these features do? Without that, it will be hard to impossible to implement them.

[arimourao]

I think he is referring to fish shell

[seagle0128]

@arimourao yes. Could refer to fish shell.
And here is the implementation in zsh/oh-my-zsh.
https://github.com/zsh-users/zsh-autosuggestions
https://github.com/zsh-users/zsh-syntax-highlighting

[nwinkler]

Sorry guys, but I'm way too busy to read through these links and figure out what you're looking for.

If you're interested in having a feature added, please provide a concise description of what you're looking for. Or even better provide a Pull Request that implements the feature. Suggestions are great, but someone will have to implement it in the end.

No offence, but I don't have time for doing this guesswork.

[seagle0128]

Okay. Let me explain the details.

What's I want exactly is Fish-like auto-suggestions as below.
The command suggestions come out automatically according to the history. It's very useful while typing the long commands. And you can also see the syntax color highlight of the commands in the screenshot.

[arimourao]

@seagle0128 it's interesting but I think this is an entire new project in its own. You or someone else interested in these features should port these to Bash. Only then bash-it could add these as plugins to be installed.

[nwinkler]

Agreed. This looks like a useful feature, but if you take a look at the project, it looks like a huge undertaking. Not sure whether Bash supports the features required for making something like this happen.

[lfelipe1501]

Hi @seagle0128 I would like to have in bash the zsh autocomplete but so far what I have found is this.

https://github.com/dvorka/hstr

I hope it works for you and that @nwinkler revises it to implement it in the framework.

Greetings.

[nwinkler]

This looks similar to fzf, which we already have a plugin for - allowing to search through your history for previous commands...

From what I've seen, the autocomplete functionality you're looking for is not easily possible in Bash...

BTW: I'm not sure why you think that I have to implement this. Feel free to provide a Pull Request if you have something you would like to see added.

[ShalokShalom]

I completely support the suggestion of @seagle0128

This is something very similar: https://github.com/scop/bash-completion

[nwinkler]

Isn't the Bash completion you linked to exactly what we already have in Bash-it's completion functionality?

[ShalokShalom]

This is what i mean: https://asciinema.org/a/37390?t=16

[ericbaranowski]

I agree with you guys, I can't believe something like that doesn't already exist for bash. Like @nwinkler said, bash probably doesn't support the features necessary to achieve the functionality, otherwise it would exist already. However, based on all these comments I'm gonna look further into the port idea.

[ShalokShalom]

I am on zsh now and very happy. Oh-my-zsh made it very easy to setup and https://github.com/zsh-users/zsh-autosuggestions add the functionality. One huge pro is that zsh is fully compatible with bash.
Solved for me..

[TimothyBramlett]

@ShalokShalom Nice, yeah I may need to the zsh route also. I love fish for its autocompletion but I hate that its not compatible with bash, which is used heavily for scripting that you are forced to use it.

[seagle0128]

I agree. I switch to zsh a few months ago and am happy as well.

[nwinkler]

Closing this now...

[bluz71]

Personally I believe Bash/Readline's existing history-search-backward and history-search-forward options are just as useful and less distracting (at least to my eye).

Add the following to ~/.inputrc:

"\e[A": history-search-backward
"\e[B": history-search-forward

Type a partial command (one that you have already executed previously) then use the UP-arrow to navigate through all the commands that match the prefix (down to go forward). Whilst it doesn't look as sexy as Fish/Zsh auto-suggestion it is just as functional.

[nwinkler]

Personally, I use fzf for that. If you install fzf and enable the fzf plugin, your Ctrl+R prompt turns into a fuzzy filter for command history, it will autocomplete previous commands as you type. I find this to be highly productive...

[benjamin-thomas]

Coming from a google search...

After seeing some advantages from fishshell over bash but still preferring a lot of bash idioms (!!, $!, $!:h, command completion with <ESC>*, etc.)

Oh...my...god!!!

@nwinkler, you just made my day!!

What an awesome tool fzf is!!

Combined with vim integration, I'm blown away..

[nwinkler]

Thanks for the kind words, @benjamin-thomas - happy to help.

fzf is indeed absolutely fantastic, one of the best shell tools I know.

In addition to the built-in functionality (Ctrl+R), the fzf plugin contains some common functions that I have adapted from the fzf Wiki, too.

I also use it ad-hoc for things like ls | fzf, together with the preview functions this is incredibly useful. Try this with the configuration from my dotfiles:

https://github.com/nwinkler/dotfiles/blob/0d5688368b6a15e701768305625a469e43170c47/home/.bash_profile#L18

# Use ag for feeding into fzf for searching files.
export FZF_DEFAULT_COMMAND='ag -U --hidden --ignore .git -g ""'
# Color: https://github.com/junegunn/fzf/wiki/Color-schemes - Solarized Dark
# Bind F1 key to toggle preview window on/off
export FZF_DEFAULT_OPTS='--bind "F1:toggle-preview" --preview "rougify {} 2> /dev/null || cat {} 2> /dev/null || tree -C {} 2> /dev/null | head -100" --color dark,hl:33,hl+:37,fg+:235,bg+:136,fg+:254 --color info:254,prompt:37,spinner:108,pointer:235,marker:235'

# Show long commands if needed
# From https://github.com/junegunn/fzf/wiki/Configuring-shell-key-bindings
# Bind F1 key to toggle preview window on/off
export FZF_CTRL_R_OPTS='--bind "F1:toggle-preview" --preview "echo {}" --preview-window down:3:hidden:wrap'

[benjamin-thomas]

These are very, very nice ideas.

Very well done, and thanks for the share!

[iamnoskcaj]

I too, love the fish shell for its unobtrusive command suggestions, inline, as I'm typing. I got so used to it. It's nice zsh has something similar (as mentioned by @ShalokShalom). I am far more comfortable in a bash similar shell, and fish is a little out there for me.

[cojack]

Impossible to achieve?

[akinomyoga]

As far as I know, it's impossible unless readline (GNU Readline, the default line editor of GNU Bash) is modified or replaced by some other line editor. I actually implemented syntax-highlighting and autosuggestions in my bash configuration (akinomyoga/ble.sh), but it replaces readline with a line editor written in bash scripts so that some behaviors might be different from those in readline. Nevertheless, maybe you like ble.sh (if you don't want to implement a new line editor and autosuggestions for yourself).

(Edit) Note: ble.sh is completely orthogonal to bash-it which defines variables, aliases, functions and completions, so both of them can be loaded as:

# bashrc

[[ $- == *i* ]] || return 0
source /path/to/blesh/ble.sh --noattach

# user settings...

source "$BASH_IT"/bash_it.sh
((_ble_bash)) && ble-attach

[gilescope]

FYI pwsh is implementing auto-suggest in their PSReadLine project. (See fish branch)

I have a dream, that one day, bash too will have auto-suggest.