*** gtp.c	2009-02-18 06:41:31.000000000 +0900
--- gtp.c	2023-11-03 18:49:30.171279432 +0900
***************
*** 45,50 ****
--- 45,52 ----
  
  #include "gtp.h"
  
+ #include <emscripten.h>
+ 
  /* These are copied from gnugo.h. We don't include this file in order
   * to remain as independent as possible of GNU Go internals.
   */
*************** static int current_id;
*** 75,80 ****
--- 77,107 ----
   */
  FILE *gtp_output_file = NULL;
  
+ /* for JavaScript line input for fgets(*,,stdin) only. */
+ EM_JS(int, my_fgets, (char *buf, int maxlen), {
+   return Asyncify.handleAsync(async () => {
+     const mySleep = function(itvl) {
+       return new Promise(function(resolve) {
+         setTimeout(function(){resolve();}, itvl);
+       });
+     };
+     const waitBuffer = async function(itvl) {
+       while(Module.fgets_buffer.length <= 0) {
+         fgbuf = await mySleep(10);
+       }
+     };
+     await waitBuffer();
+     const input = Module.fgets_buffer.shift();
+     const len = Math.min(input.length, maxlen);
+     if (len === input.length) {
+       HEAPU8.set(input, buf);
+     } else {
+       HEAPU8.set(input.subarray(0, len), buf);
+       Module.fgets_buffer.unshift(input.subarray(len));
+     }
+     return len;
+   });
+ });
  
  /* Read filehandle gtp_input linewise and interpret as GTP commands. */
  void
*************** gtp_main_loop(struct gtp_command command
*** 92,98 ****
  
    while (status == GTP_OK) {
      /* Read a line from gtp_input. */
!     if (!fgets(line, GTP_BUFSIZE, gtp_input))
        break; /* EOF or some error */
  
      if (gtp_dump_commands) {
--- 119,125 ----
  
    while (status == GTP_OK) {
      /* Read a line from gtp_input. */
!     if (!my_fgets(line, GTP_BUFSIZE))
        break; /* EOF or some error */
  
      if (gtp_dump_commands) {