The case.h header

#include "/package/prog/prjlibs/include/case.h"
CASE_IS_UPPER('A')==1;
CASE_IS_LOWER('a')==1;
CASE_TO_UPPER('a')=='A';
CASE_TO_LOWER('A')=='a';

The case.h C header file defines macros for upper/lowercase character operations. These macros are not locale-sensitive, and depend on the ASCII character set.

• CASE_IS_UPPER(c) yields a true value if the given character is an uppercase letter.
• CASE_IS_LOWER(c) yields a true value if the given character is a lowercase letter.
• CASE_TO_UPPER(c) yields the uppercase version of a lowercase letter, or the character itself if it is not a lowercase letter.
• CASE_TO_LOWER(c) yields the lowercase version of an uppercase letter, or the character itself if it is not an uppercase letter.