ctype.h

Contiene funzioni per verifiche e operazioni conversione su caratteri. Segue la lista completa:

       int isalnum(int character);
       int isalpha(int character);
       int iscntrl(int character);
       int isdigit(int character);
       int isgraph(int character);
       int islower(int character);
       int isprint(int character);
       int ispunct(int character);
       int isspace(int character);
       int isupper(int character);
       int isxdigit(int character);
       int tolower(int character);
       int toupper(int character);