Alt-g and Readline shortcuts that make Bash completion a bit more convenient

Let’s say you’re using Bash and you have a directory like this:

$ ls
aaa-bbb-ccc

You want to move to this directory, but you only remember bbb in the middle of the name, not the leading aaa.

You might be tempted to do:

cd bbb<TAB>

But normal Bash TAB completion is basically prefix-based, so this won’t complete aaa-bbb-ccc.

That’s where glob comes in.

cd *bbb*

Since * matches any string, aaa-bbb-ccc matches.

However, here you might want a bit more:

cd *bbb*

At the point you’ve typed this, you want it to expand to:

cd aaa-bbb-ccc/

so you can confirm before executing.

That’s where Alt-g comes in handy.

Alt-g: Complete using glob

Readline, which handles Bash’s command-line editing, has a feature called glob-complete-word.

It’s assigned to Alt-g by default, so if you type:

cd *bbb*

and press Alt-g, it can complete using names that match the glob.

For example:

$ cd *bbb*<Alt-g>

becomes:

$ cd aaa-bbb-ccc/

This is quite handy when you only remember part of a name.

If you use it alongside normal TAB completion:

cd aaa<TAB>       # when you remember the beginning
cd *bbb*<Alt-g>   # when you only remember the middle

Ctrl-x *: Expand glob in place

Something worth remembering alongside Alt-g is:

Ctrl-x *

This is glob-expand-word, which expands the glob pattern itself into the matched filenames.

For example:

$ echo *bbb*

If you press Ctrl-x *, it becomes:

$ echo aaa-bbb-ccc

If multiple names match, they all get expanded together.

A good way to think about it:

Alt-g      → "complete" using glob
Ctrl-x *   → "expand" using glob

Alt-.: Reuse the last argument of the previous command

One shortcut I personally recommend remembering if you use Bash is Alt-..

For example:

mkdir /tmp/very-long-directory-name

Immediately after running that, if you do:

cd <Alt-.>

You get:

cd /tmp/very-long-directory-name

In other words, it inserts the last argument of the previous command.

This also works for creating a file and then immediately opening it:

touch some-very-long-filename.txt
vim <Alt-.>

If you press Alt-. repeatedly, you can go further back through the last arguments of older commands.

Ctrl-r: Search command history

Many people probably already know this one, but Ctrl-r is also very useful.

Pressing it lets you incrementally search through past commands.

For example, if you previously ran:

docker compose exec app bundle exec rails console

and want to run it again, you don’t need to scroll endlessly through history with the arrow keys.

Just press Ctrl-r and type:

rails

and it will find history entries containing that.

This is essential if you frequently reuse long commands.

Ctrl-x Ctrl-e: Edit the current command in an editor

When commands get long, editing on a single line in the shell can become painful.

In that case, press:

Ctrl-x Ctrl-e

This lets you edit the command you’re currently typing in $EDITOR.

For example, if you’re in the middle of building a long command like:

find . -type f -name '*.log' -mtime +7 ...

you can press:

Ctrl-x Ctrl-e

and edit it in your configured editor such as vim or nano.

When you save and exit, the content is returned to the shell and executed.

This is very handy for complex one-liners.

Other useful Readline operations to remember

Bash uses Emacs-style Readline keybindings by default.

Here’s a summary of commonly used ones:

You don’t need to memorize all of them.

Just remembering:

Alt-g
Alt-.
Ctrl-r
Ctrl-x Ctrl-e
Ctrl-x *

is enough to make Bash operations considerably easier.

You can also assign TAB to glob completion

By the way, if you change the Readline settings, you can assign glob-complete-word (normally on Alt-g) to TAB.

In ~/.inputrc, add:

"\t": glob-complete-word

Then you can do:

cd *bbb*<TAB>

However, this replaces normal TAB completion.

Since it also affects everyday operations like:

cd aaa<TAB>

I personally prefer keeping TAB as normal completion and using:

normal completion → TAB
glob completion   → Alt-g

as a division of roles, which I find easier to handle.

Summary

The discovery here is simple:

For a directory like:

aaa-bbb-ccc/

if you type:

cd *bbb*

and press:

Alt-g

you get glob-based completion.

Bash has quite a few Readline features that you won’t easily notice if you only ever use TAB and arrow keys.

In particular, these five:

Alt-g          glob completion
Ctrl-x *       glob expansion
Alt-.          reuse previous argument
Ctrl-r         history search
Ctrl-x Ctrl-e  edit in editor

are worth knowing and will help in everyday shell operations.

If you want to speed up your Bash workflow, beyond just adding commands and tools, looking into Readline keybindings is also recommended.