btowc
wint_t btowc(int);
PROTO_NORMAL(btowc);
DEF_STRONG(btowc);
*(cp = buf) = (wchar_t)btowc(GETARG(int));
while (pt < ptlim && (*pt = btowc(*str++)) != L'\0')
result = btowc(ch);
eols = zero_ended ? btowc('\0') : btowc('\n');
eols = zero_ended ? btowc('\0') : btowc('\n');
sort_opts_vals.field_sep = btowc(optarg[0]);