ruby-wcswidth.c

#define _XOPEN_SOURCE
#include <wchar.h>
#include <stdlib.h>
#include <ruby.h>

static VALUE width(VALUE self, VALUE string) {
  wchar_t* dest;
  int ret, len;

  Check_Type(string, T_STRING);
  len = RSTRING_LEN(string);
  dest = (wchar_t*)calloc(len, sizeof(wchar_t));
  ret = mbstowcs(dest, RSTRING_PTR(string), len);

  if(ret == -1) return Qnil;

  ret = wcswidth(dest, RSTRING_LEN(string));

  free(dest);

  return INT2NUM(ret);
}

void Init_WcsWidth() {
  VALUE cWcsWidth;

  cWcsWidth = rb_define_class("WcsWidth", rb_cObject);
  rb_define_module_function(cWcsWidth, "width", width, 1);
}