I am planning to develop a cross-platform script. On Linux and other operating systems, it will store configuration in XDG_CONFIG_HOME and data files (specifically,
I would use ~/Library/Application Support/script_name/. The subdirectories inside Application Support are used conventionally by various apps, including Apple's own softwares. But it's not enforced by the OS and not tied to apps inside /Applications. So you're perfectly free to create your own directory in it.
For the directory structure of OS X in general, see this Apple document.
I agree with OJFord's comment: if you are writing a script (I think this applies to all CLI-only application), simply follow the XDG Base Directory would be better.
Rationales:
XDG_CONFIG_HOME are typically small-case bare-names like git; the ones in ~/Library/Preferences/ are typically scoped with reversed domain names like com.apple.foo-bar, or first-letter-capital space-delimited names like Foo Bar./Applications. You don't place your script in /Applications; you place them in UNIX-specific directorys. Better to be consistent.~/Library/Preferences/ is full of .plists. No cross-platform script that I know is using property lists.For example, Git places their config file in XDG_CONFIG_HOME/git/config, not in ~/Library/Preferences/Git/config. Makes sense to me.
I made the point only for configuration files ($XDG_CONFIG_HOME) and data files ($XDG_DATA_HOME); for cache files it gets subtle. According to How-To Geek, ~/Library/Caches directory is excluded from Time Machine by default. I don’t care about cache folder since I back up neither directories anyway; but for ones who care, I recommend them to link ~/.cache to somewhere in the default cache folder, such as:
cd ~; mv .cache ~/Library/Caches/XDG-cache; ln -s ~/Library/Caches/XDG-cache .cache
Comparing Apple's documentation for the various paths to the XDG Base Directory specifications approximates to the following locations:
XDG_CONFIG_HOME ▶︎ ~/Library/Preferences/XDG_DATA_HOME ▶︎ ~/Library/XDG_CACHE_HOME ▶︎ ~/Library/Caches/Mapping XDG Base Directory Specification locations for "My App" on Mac OS X could look like this:
XDG_CONFIG_HOME ▶︎ ~/Library/Preferences/name.often.with.domain.myapp.plistXDG_DATA_HOME ▶︎ ~/Library/My App/XDG_CACHE_HOME ▶︎ ~/Library/Caches/My App/These mappings seem pretty reasonable but they aren't exact. Some kinds of cache or data may be appropriate for ~/Library/Application Support/My App, and other may be best in the temp locations or the App bundle. All of it is by convention and the same reasons for using the best XDG_ locations apply to using the best locations on the Mac OS X system.
Your annoyance at ~/.myscript is in line with Apple's guidelines: "Don't pollute user space".
References: