Explanation for newbies:
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Shell is the programming language that you use when you open a terminal on linux or mac os. Well, actually "shell" is a family of languages with many different implementations (bash, dash, ash, zsh, ksh, fish, ....)
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Writing programs in shell (called "shell scripts") is a harrowing experience because the language is optimized for interactive use at a terminal, not writing extensive applications
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The two lines in the meme change the shell's behavior to be slightly less headache-inducing for the programmer:
set -euo pipefailis the short form of the following three commands:set -e: exit on the first command that fails, rather than plowing through ignoring all errorsset -u: treat references to undefined variables as errorsset -o pipefail: If a command piped into another command fails, treat that as an error
export LC_ALL=Ctells other programs to not do weird things depending on locale. For example, it forcesseqto output numbers with a period as the decimal separator, even on systems where coma is the default decimal separator (russian, dutch, etc.).
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The title text references "posix", which is a document that standardizes, among other things, what features a shell must have. Posix does not require a shell to implement
pipefail, so if you want your script to run on as many different platforms as possible, then you cannot use that feature.
I even use powershell as my main scripting language on my Mac now. Iโve come around.
That's sounds terrible honestly
Iโm so used to using powershell to handle collections and pipelines that I find I want it for small scripts on Mac. For instance, I was using ffmpeg to alter a collection of files on my Mac recently. I found it super simple to use Powershell to handle the logic. I could have used other tools, but I didnโt find anything about it terrible.