HelenOS sources

isxdigit          102 common/stdc/ctype.c int isxdigit(int c)
isxdigit          102 kernel/generic/common/stdc/ctype.c int isxdigit(int c)
isxdigit          102 uspace/lib/c/common/stdc/ctype.c int isxdigit(int c)
isxdigit          109 uspace/lib/cpp/include/__bits/locale/locale_misc.hpp     bool isxdigit(Char c, const locale& loc)