Checking if a pointer is allocated memory or not

Question

Can we check whether a pointer passed to a function is allocated with memory or not in C?

I have wriiten my own function in C which accepts a character pointer -

Answer 1

in general lib users are responsible for input check and verification. You may see ASSERT or something in the lib code and they are used only for debug perpose. it is a standard way when writing C/C++. while so many coders like to do such check and verfying in their lib code very carefully. really "BAD" habits. As stated in IOP/IOD, lib interfaces should be the contracts and make clear what will the lib do and what will not, and what a lib user should do and what should be not necessary.