HelenOS sources

iscntrl            67 common/stdc/ctype.c int iscntrl(int c)
iscntrl            67 kernel/generic/common/stdc/ctype.c int iscntrl(int c)
iscntrl            67 uspace/lib/c/common/stdc/ctype.c int iscntrl(int c)
iscntrl            73 uspace/lib/cpp/include/__bits/locale/locale_misc.hpp     bool iscntrl(Char c, const locale& loc)