Streamline your Bash scripts with expert guidance on best practices and code organization.

Bash Scripting Best Practices

1. Shebang Line

Start your script with a shebang line to specify the interpreter:

#!/bin/bash

2. Script Info

Include script information such as name, date, author, and description:

################################################################################
# Name:        myscript.sh
# Date:        2024-04-14
# Author:      Sam
# Description: My awesome script.
################################################################################

3. Figlet or Toilet

Use figlet or toilet to generate the name of the script in large letters, commented out:

figlet "My Script" | sed 's/^/# /'

# ▙▗▌▌ ▌  ▞▀▖▞▀▖▛▀▖▜▘▛▀▖▀▛▘
# ▌▘▌▝▞   ▚▄ ▌  ▙▄▘▐ ▙▄▘ ▌ 
# ▌ ▌ ▌   ▖ ▌▌ ▖▌▚ ▐ ▌   ▌ 
# ▘ ▘ ▘▀▀▀▝▀ ▝▀ ▘ ▘▀▘▘   ▘ 

4. Source External Scripts

In this section of your script, you should source external scripts that provide additional functionality. Use the full path to the script and include a comment explaining what it does, along with a link to the project page for reference.

Example:

# Source external scripts for additional functionality

# Get extract flags from arguments as variables using: https://github.com/AmosNimos/flag
. /path/to/flag_utility
flag_utility "$@"

Make sure to replace /path/to/flag/utility with the actual path to the external script in your system. This practice helps maintain transparency and allows users to understand the purpose of the sourced script.

5. Print Help

Add a function to print the script's help information:

print_help() {
    echo "Usage: $0 [OPTIONS]"
    echo "Options:"
    echo "  -h, --help    Show help information"
}

You can use a here document (heredoc) to create multi-line strings in Bash, which is particularly useful for printing help messages. Here's an example of how you can define the help message using a heredoc:

print_help() {
    cat << EOF
Usage: $0 [OPTIONS]

Options:
  -h, --help    Show help information
  -v, --version Show version information
EOF
}

In this example, cat << EOF starts the heredoc, and EOF marks the end of the heredoc. The text between EOF and EOF will be treated as a multi-line string and printed by cat. You can adjust the help message content as needed.

6. Initializing Global Variables

Initialize global variables using capital letters and no spaces:

GLOBAL_VARIABLE="value"

7. Reading Arguments

Read and parse command-line arguments using if or case statements:

if [[ "$1" == "-h" || "$1" == "--help" ]]; then
    print_help
    exit 0
fi

8. Functions

Define your functions after argument parsing:

my_function() {
    local local_variable="value"
    echo "Function executed"
}

10. Additional Notes

• Use comments generously to explain your code's logic and purpose.