busybox

Yes, and it lives on in a variety of minimalist environments under active development, such as: * U-boot: https://github.com/u-boot/u-boot/blob/master/common/cli_hush... * Busybox: https://github.com/brgl/busybox/blob/master/shell/hush.c * Barebox: https://github.com/barebox/barebox/blob/master/common/hush.c

I believe you can fairly easily spot recursive search tree implementations in the wild, in production code. Compilers and interpreters often use recursion, and that goes to as many levels as the program requires. Garbage collectors that use recursion to traverse the reachable objects are not unheard of. Reference counting smart pointers are recursive. E.g. when we call object->dropReference(), and the refcount goes to zero, that may trigger otherObject->dropReference(). In C++, recursion is built into the language; e.g. destroying an object can trigger a cascade of recursive destructor calls. The object may have members which are smart pointers; those get destroyed, and may cause their referenced objects to get recursively destroyed. Have you heard of a "recursive descent parser"? GNU C++ uses one (a huge source file written in C++, well

Doesn't memcpy have the same issue as strncpy? the destination will not be null terminated if the source is too long. Many projects just implement a safe_strncpy wrapper that always terminates the destination. Example: https://github.com/brgl/busybox/blob/master/libbb/safe_strnc...