# Functions

Functions organize your code for reuse. Here's the structure:

```bash
function_name() {
    your_commands
}
```

You can also use the `function` keyword for clarity, though it's optional:

```bash
function function_name() {
    your_commands
}
```

Example: A simple 'Hello World!' function.

```bash
touch hello_function.sh
```

Open `hello_function.sh` and add:

```bash
#!/usr/bin/env bash

function hello() {
    echo "Hello World Function!"
}

hello # Call the function (no parentheses)
```

Save and exit. Make it executable and run:

```bash
chmod +x hello_function.sh
./hello_function.sh
```

Functions accept arguments just like scripts.

```bash
touch function_args.sh
```

Open `function_args.sh` and add:

```bash
#!/usr/bin/env bash

function greet_team() {
    echo "Hello $1!"
}

greet_team "Dev Team Six" # Pass argument when calling
```

Save and exit. Make it executable and run:

```bash
chmod +x function_args.sh
./function_args.sh
```

Document your functions clearly. Include a description, arguments, and expected output/return values.

```bash
#######################################
# Description: Greets a single argument.
# Globals: None
# Arguments:
#   $1 - Name/value to greet.
# Outputs:
#   Prints a greeting to stdout.
# Returns:
#   0 on success.
#######################################
function greet_example() {
    echo "Greeting: $1"
}
```

Functions are key to building organized and reusable Bash scripts. Master them for efficient automation.