LD_PRELOAD is an environment variable that can be set to load ELF
shared objects before all others. Linux and BSD are known to fit.
This change also unifies the use of command line, ensuring the prefix
"> " prompt.
Some documents explain passing MIMALLOC_STATS=1 to print
statistics, though it handles as mimalloc_show_stats in the actual
code. According to the code, change the name MIMALLOC_STATS to MIMALLOC_SHOW_STATS.
In 2012, with the release of OS X 10.8 Mountain Lion, the name of the
system was shortened from Mac OS X to OS X. In 2016, with the release
of macOS 10.12 Sierra, the name was changed from OS X to macOS to
streamline it with the branding of Apple's other primary operating
systems: iOS, watchOS, and tvOS.
Reference: https://en.wikipedia.org/wiki/MacOS