HelenOS sources

isalpha            47 common/stdc/ctype.c int isalpha(int c)
isalpha            47 kernel/generic/common/stdc/ctype.c int isalpha(int c)
isalpha           107 kernel/generic/include/macros.h #define isalpha(c)     (is_lower((c)) || is_upper((c)))
isalpha            47 uspace/lib/c/common/stdc/ctype.c int isalpha(int c)
isalpha            91 uspace/lib/cpp/include/__bits/locale/locale_misc.hpp     bool isalpha(Char c, const locale& loc)