- eval '*EINPROGRESS = sub { 10036 };';
- eval '*EWOULDBLOCK = *EAGAIN = sub { 10035 };';
- eval '*F_GETFL = sub { 0 };';
- eval '*F_SETFL = sub { 0 };';
- eval '*IPPROTO_TCP = sub { 6 };';
- eval '*TCP_NODELAY = sub { 1 };';
+ eval '*EINPROGRESS = sub { 10036 };' unless defined *EINPROGRESS;
+ eval '*EWOULDBLOCK = *EAGAIN = sub { 10035 };' unless defined *EWOULDBLOCK;
+ eval '*F_GETFL = sub { 0 };' unless defined *F_GETFL;
+ eval '*F_SETFL = sub { 0 };' unless defined *F_SETFL;
+ eval 'sub IPPROTO_TCP { 6 };';
+ eval 'sub TCP_NODELAY { 1 };';