Fossil

  /* Check to see the If-Modified-Since constraint is satisfied */
  zIfModifiedSince = P("HTTP_IF_MODIFIED_SINCE");
  if( zIfModifiedSince==0 ) return;
  x = cgi_rfc822_parsedate(zIfModifiedSince);
  if( x<=0 || x>mtime ) return;

#if 0  
  /* If the Fossil executable is more recent than If-Modified-Since,
  ** go ahead and regenerate the resource. */
  exeMtime = file_mtime(g.nameOfExe, ExtFILE);
  if( exeMtime>x ) return;
#endif

  /* If we reach this point, it means that the resource has not changed
  ** and that we should generate a 304 Not Modified reply */
  cgi_reset_content();
  cgi_set_status(304, "Not Modified");
  cgi_reply();
  fossil_exit(0);