HelenOS sources

isupper            42 common/stdc/ctype.c int isupper(int c)
isupper            42 kernel/generic/common/stdc/ctype.c int isupper(int c)
isupper           106 kernel/generic/include/macros.h #define isupper(c)     (((c) >= 'A') && ((c) <= 'Z'))
isupper            42 uspace/lib/c/common/stdc/ctype.c int isupper(int c)
isupper            79 uspace/lib/cpp/include/__bits/locale/locale_misc.hpp     bool isupper(Char c, const locale& loc)