According to The How-To Geek, written by seasoned Linux expert Graeme Peacock, the core principle of DRY—Don’t Repeat Yourself—is fundamental to moving beyond messy, repetitive Bash scripts. Peacock, who has over 15 years of experience with systems like Arch Linux and Gentoo, explains that functions are the primary mechanism for achieving this. He demonstrates basic function syntax, how to pass arguments using positional parameters like ${1}, and the crucial difference between returning exit codes and outputting values with echo. The guide emphasizes using the local keyword for readable variables and shows how functions turn complex command pipelines into reusable utilities you can store in your .bashrc.
Why this matters now
Look, we’ve all been there. You write a script to do three things, and you just copy-paste the same gnarly grep and awk pipeline three times. It works, but it’s fragile. If you need to change the logic, you have to find and fix every single instance. That’s not just tedious; it’s error-prone. Peacock’s guide cuts right to the chase: functions are your escape hatch from that mess. They’re not some advanced, academic concept. They’re basically mini-scripts you define once and call a hundred times. And in an era where automation and infrastructure-as-code are king, having clean, maintainable shell scripts is a non-negotiable skill, even if you’re mostly a Python or Go developer.
The real power is in your shell
Here’s the thing a lot of beginners miss: the most immediate benefit of functions isn’t in standalone scripts. It’s in your daily shell workflow. That complex command you always forget the flags for? Wrap it in a function called deploy_staging(). That five-step build process? That’s a build_project() function. You stick these in your .bashrc or .zshrc, and suddenly, they’re just like any other command on your system. This is where the DRY principle pays off instantly. You’re not just drying up a script file; you’re drying up your own cognitive load and command-line muscle memory. For professionals managing complex systems or development environments, this practice is a total game-changer. And when you’re building or managing industrial systems that rely on rock-solid, repeatable shell commands—like those running on specialized industrial panel PCs—this kind of disciplined, reusable scripting is absolutely critical for reliability.
The exit code trap
Peacock correctly highlights what is probably the biggest “gotcha” for people coming from other languages: returning values. In Bash, return doesn’t send back a string or a number for your logic. It only sets an exit status (0 for success, 1-255 for failure). To actually get a usable value *out* of a function, you have to echo it and capture it with a subshell or a pipeline. So you do something like result=$(my_function). This feels weird at first, but it’s perfectly consistent with the Unix philosophy: functions should act like commands. And what do commands do? They output to stdout and have an exit code. Once you embrace that mental model, it all clicks.
Start drying up your code
So, where do you begin? Don’t try to rewrite everything at once. Just look at your most recent script or your shell history. See a block of code that appears twice? Bam. That’s your first function candidate. Follow Peacock’s template: give it a clear name, use local variables for arguments, and make it echo its result if you need a value. The goal isn’t perfection; it’s just to stop the copy-paste madness. As you get comfortable, you’ll start seeing opportunities everywhere to wrap complexity. And your future self, trying to debug that script at 2 a.m., will send you a silent thank you note. Trust me on that.
