native_getusershell function
Successive calls return the shells listed in `/etc/shells'.
Implementation
ffi.Pointer<Utf8> native_getusershell() {
_getusershell ??= Libc()
.dylib
.lookupFunction<ffi.Pointer<Utf8> Function(), _dart_getusershell>(
'getusershell');
return _getusershell!();
}