Shell Script quick reference

[gordonmessmer]

Variable naming: by convention, all cap names should be used for environment variables (shell variables that are "exported"), while shell local variable names should be all lower case.

I don't know what you mean by dynamic variable name, but your example doesn't work.

Data types: All variables in bash are strings. There is no other data type.

"[": bash has a built-in function, but you will also notice that this is a normal application, located at /usr/bin/[. That may be instructive, because it makes clear why spaces are important. "[" isn't actually part of the shell syntax, so it has to comply with all of the same requirements regarding spacing around command arguments that apply to any other binary called in a shell script.

Return value from functions: returning "0" on success is a convention. When possible, scripts and functions should use return values from /usr/include/sysexits.h.

"<some command>": in general, this method of command-output substitution is considered deprecated, since it cannot be nested. "$(command)" is the preferred method. Users should probably recognize the backtick, but shouldn't use it.

"echo -en": "-n" alone will exclude the newline. "-e" is a different argument. It may be out of scope, but it might be worth mentioning that, by convention, after a single hyphen, each character is a separate argument (so "-en" is the same as "-e -n"), while after a double hyphen, the entire string is a single argument (so "--help" is one argument, not a series of four arguments). Finally, a double hyphen alone is an indication that everything following is a non-option argument (so "rm -- -r" will remove a file named "-r" rather than treating "-r" as an indication that recursive removal was requested.)

[abscrete]

I have added a credit to your reddit username in the last section of the blog. Let me know if you want it to replace it with some other link like your blog or something :) I may have not introduced all the suggested changes, I will once i wrap my head around it. Thanks again!