socket_send.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */
 
/**
 * @file socket_send.c
 * @brief Implements OP_SOCK_SEND to transmit data over a connected socket.
 *
 * Behavior:
 * - Pops data (string) and a socket file descriptor (int) and pushes the number of bytes sent (>=0) or -1 on error.
 * - On non-UNIX platforms, pushes -1 (unsupported) without sending.
 *
 * Errors:
 * - If argument types are wrong, prints an error, frees values, and pushes -1.
 */
 
case OP_SOCK_SEND: {
  /* Pops data string, fd; pushes bytes sent (>=0) or -1 */
  Value datav = pop_value(vm);
  Value fdv = pop_value(vm);
  int sent = -1;
#ifdef __unix__
  if (fdv.type != VAL_INT || datav.type != VAL_STRING) {
    fprintf(stderr, "Runtime type error: sock_send expects (int fd, string data)\n");
    free_value(datav);
    free_value(fdv);
    push_value(vm, make_int(-1));
    break;
  }
  int fd = (int)fdv.i;
  const char *buf = datav.s ? datav.s : "";
  size_t len = strlen(buf);
  ssize_t n = send(fd, buf, len, 0);
  if (n >= 0)
    sent = (int)n;
  else
    sent = -1;
#endif
  free_value(datav);
  free_value(fdv);
  push_value(vm, make_int(sent));
  break;
}