In Bash, you can declare functions using the function keyword followed by the function name and the function body enclosed in curly braces {}. Here’s the syntax for function declarations in Bash:
function function_name {
# Function body
# ...
}
Alternatively, you can omit the function keyword and declare functions directly with just the function name and the function body:
function_name() {
# Function body
# ...
}
Here’s an example that demonstrates the declaration and usage of a function in Bash:
#!/bin/bash
# Function declaration
greet() {
echo "Hello, world!"
}
# Calling the function
greet
In this example, the function greet is declared with the function body echo "Hello, world!". The function is then called using greet, and when the script is executed, it will output:
Hello, world!
Functions in Bash allow you to encapsulate a sequence of commands or actions and reuse them throughout your script. You can define functions at any point in your script, and they can be called multiple times from different parts of the script.
It’s worth noting that Bash supports both named and anonymous functions. Named functions have a specific name and can be called by their name, as shown in the example above. On the other hand, anonymous functions, also known as inline functions or lambda functions, are defined without a name and can be used in specific contexts where a function is expected, such as in command substitutions or as arguments to other commands.