toupper() ctype macro toupper() Convert characters to upper case #include <ctype.h> int toupper(c) int c; toupper is a macro that converts the letter c to upper case and returns the converted character. If c is not a letter or is al- ready upper case, then toupper returns it unchanged. ***** Example ***** For examples of this routine, see the entries for ctype and tolower. ***** See Also ***** ctype, tolower() COHERENT Lexicon Page 1