Bash doesn't expand variables when pressing Tab key

Question

In the previous versions of Ubuntu 18.04, the variables in Bash are expanded when I press the Tab key. But in Ubuntu 20.04 (using bash 5.0.16), the variables are not expanded. Instead, the dollar sign $ before the variable gets proceeded by a backslash.

For example, let's say, I have a variable MY_DIRECTORY:

export MY_DIRECTORY=/path/to/a/folder

Now when I write something like this:

ls $MY_DIRECTORY<Tab key>

I get:

ls \$MY_DIRECTORY

As you can see, the variable doesn't expand to the desired path. What is wrong with that?

Similar question yesterday: How to disable automatic backslash insert when using environment variable names on Ubuntu 20.04 LTS terminal(s) — steeldriver, May 30 '20 at 20:17
Why do you want it to be expanded to a path ? It would work even without expansion. — Parsa Mousavi, May 31 '20 at 10:14
@ParsaMousavi: because that breaks autocompletion for paths that are given as variables. — IamNotaMathematician, May 31 '20 at 10:36
It looks like this was also answered 10 years ago: How to get bash to stop escaping $ during tab completion? — Anthony Geoghegan, Dec 10 '21 at 18:57
It could not be answered 10 years ago if the OP is noticing the behaviour changed between Ubuntu 18 and 20 ;). Yes the issue is the same, but the cause it not the same as 10 years ago. It depends on the specific versions of Bash, bash-completion and the specific patches that each Linux distribution apply to both of these. — philb, May 17 '22 at 22:23

BeastOfCaerbannog · Accepted Answer · 2021-06-30T09:08:22.297

You have the following two options for expanding a variable in Bash:

Use the Ctrl+Alt+E keyboard shortcut whenever you want to expand a variable.

For example, if I write in my terminal:
```
$LANG $BASH
```
and then press the shortcut, the above will expand both variables to:
```
en_US.UTF-8 /usr/bin/bash
```
Enable the shopt builtin's direxpand option by running in your terminal:
```
shopt -s direxpand
```
Now, if you type:
```
ls $MY_DIRECTORY/<Tab key>
```
it will be expanded to:
```
ls /path/to/a/folder/
```
To have the direxpand option enabled for all terminal sessions, append shopt -s direxpand in your ~/.bashrc file either manually or by running:
```
echo "shopt -s direxpand" >> ~/.bashrc
```

Bash doesn't expand variables when pressing Tab key

1 Answers1