is errno STRUNCATE specific to windowsOS looking for its equivalent in linux/mac. using it in implementation of mbstowcs_s()

Question

Is errno STRUNCATE specific to windows OS? looking for its equivalent in mac/linux.

implementing mbstowcs_s() for mac/linux, following https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/mbstowcs-s-mbstowcs-s-l?view=vs-2019, mbstowcs_s() returns STRUNCATE for one condition, trying to understand where STRUNCATE is defined, so that it can be reused properly in mac/linux.

Answer 1

STRUNCATE is a Windows thing (value 80), so you will need to define it yourself. On Windows, it is declared in errno.h.