forth/src/fh_builtins_stdin.c

#include "forth_internal.h"
 
#include <unistd.h>
#include <termios.h>

static char getch() {
        char buf = 0;
        struct termios old = {0};
        if (tcgetattr(0, &old) < 0)
                perror("tcsetattr()");
        old.c_lflag &= ~ICANON;
        old.c_lflag &= ~ECHO;
        old.c_cc[VMIN] = 1;
        old.c_cc[VTIME] = 0;
        if (tcsetattr(0, TCSANOW, &old) < 0)
                perror("tcsetattr ICANON");
        if (read(0, &buf, 1) < 0)
                perror ("read()");
        old.c_lflag |= ICANON;
        old.c_lflag |= ECHO;
        if (tcsetattr(0, TCSADRAIN, &old) < 0)
                perror ("tcsetattr ~ICANON");
        return (buf);
}


static enum fh_error w_key(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a;
  
  a = getch();
  
  TRY(ds_push(fh, a));
  return FH_OK;
}

static inline bool iscrlf(char c) {
  return c == '\r' || c == '\n';
}

static enum fh_error w_accept(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t abuf;
  uint32_t count;
  
  TRY(ds_pop(fh, &count));
  TRY(ds_pop(fh, &abuf));
  
  char *s = fgets(&fh->heap[abuf], count, stdin);
  if (!s) {
    LOGE("Error reading stdin!");
    count = 0;
  } else {
    count = strnlen(s, count);
    // remove the newline
    if(count > 0) {
      char *end = s + (count - 1);
      while (iscrlf(*end)) {
        end--;
        count--;
      }
    }
  }
  
  TRY(ds_push(fh, count));
  return FH_OK;
}

const struct name_and_handler fh_builtins_stdin[] = {
    {"key",  w_key,          0, 0},
    {"accept",  w_accept,          0, 0},
    { /* end marker */ }
};