I'm writing a bash script for building containers with Podman, and I'm running into some issues between my laptop, which is an M2 MacOS with an older version of bash (3.x), and my server that uses Alma Linux (RHEL) 9.5. I'm executing a command to start a Postgres instance, but I've noticed some discrepancies. For instance, a line in my script works on macOS: `modified_line="${modified_line//:'sp'/'$sp'}"`, while the commented version for Linux doesn't. The results are also different; the macOS version creates the file correctly, but the Linux version appends doubled content, which isn't what I want. I'm wondering how to write bash code that's compatible across both systems. Should I switch to fish or maybe another language to avoid these version problems? Or is it worth running everything in containers to bypass the MacOS quirks?
4 Answers
Definitely install Homebrew first and then bash! You'll marvel at how easily you can switch versions. Just keep in mind that scripting can have quirks between systems, but with tools like shellcheck, you can solve many issues before they arise.
If you want to avoid these versioning headaches, running your scripts inside containers is a solid option. You'll ensure consistency as your containers can have the same environment no matter where they run. Plus, it saves you the hassle of figuring out different system behaviors!
Installing a newer bash version on your Mac using Homebrew can be a game changer. Run `brew install bash` and you’ll find a lot more features available that align with what you see on Linux. Also, don't forget to check out shellcheck for debugging your scripts—it’s super helpful!
To tackle the compatibility issue, consider writing your scripts in a more POSIX-compliant manner. That way, the shebang and structure can align better across different systems. Also, using double quotes for variable expansions can help, like `modified_line="${modified_line//:'sp'/'"$sp"'}"` which might work on both platforms. You might also think about using `zsh` or ensure a modern bash version is installed on both your Mac and server.
Wow, didn't realize I could just change the quotes! Thanks for the tip! I’ll give it a shot.