Is C function case sensitive?

It is case-insensitive . The behavior is NOT undefined (it is well-defined) if either string is a null ptr. Regular strncmp() has undefined behavior if either string is a null ptr (see: https://en.cppreference.com/w/cpp/string/byte/strncmp).

It is case-insensitive . The behavior is NOT undefined (it is well-defined) if either string is a null ptr. Regular strncmp() has undefined behavior if either string is a null ptr (see: https://en.cppreference.com/w/cpp/string/byte/strncmp).

Anything that is case sensitive discriminates between uppercase and lowercase letters . In other words, it means that two words that appear or sound identical but are using different letter cases, are not considered equal.

Anything that is case sensitive discriminates between uppercase and lowercase letters . In other words, it means that two words that appear or sound identical but are using different letter cases, are not considered equal.