How do I assign long git commands to a variable or function in a bash script?

Remember when you define your command, don't use quotes around the variable when referencing it in your commands. For example:

```bash
MY_COMMAND='git --work-tree=/path/to/work/tree --git-dir=/path/folder'
$MY_COMMAND commit -m "new commit"
```

Single quotes keep the command unchanged, while referencing the variable without quotes allows for proper argument passing.

You mistakenly used back quotes instead of single quotes, which executes the command immediately. An alias might be easier to use here.

```bash
alias MY_COMMAND='git --work-tree=/path/to/work/tree --git-dir=/path/folder'
```

But remember you might need to use 'interactive mode' based on your setup, it varies depending on the environment you're working in!

I noticed you're using backticks in your initial approach. That's for command execution, not what you meant. Instead, you should use single quotes for your variable and reference it like this:

```bash
MY_COMMAND='git --work-tree=/path/to/work/tree --git-dir=/path/folder'

$MY_COMMAND commit -m "new commit"
$MY_COMMAND push
```

This should work just fine!

You can also set environment variables at the start of your script that will apply to all git commands. Just export them like this:

```bash
export GIT_DIR="/path/folder"
export GIT_WORK_TREE="/path/to/work/tree"
```

This way, all git commands in your script will use these values automatically! Check out the Git documentation for more on environment variables.

Instead of using a variable, I recommend using an alias since you just want to set some default flags. You can do it like this:

```bash
alias git='git --work-tree=/path/to/work/tree --git-dir=/path/folder'
```

Then you can call commands like `git push` normally without any issues! If you have a more complex requirement, consider using a function like this:

```bash
mygit() {
git --work-tree="/path/to/work/tree" --git-dir="/path/folder" "$@"
}
```

This way, you can pass arguments to it as needed!