capability.c

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/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
***********************************************************************/
 
#ifdef HAVE_CONFIG_H
#include <fc_config.h>
#endif
 
#include "fc_prehdrs.h"
 
#include <string.h>
 
/* utility */
#include "shared.h"             /* TRUE, FALSE */
#include "support.h"            /* fc_is* */
 
#include "capability.h"
 
#define GET_TOKEN(start, end)                                               \
  {                                                                         \
    /* skip leading whitespace */                                           \
    while (fc_isspace(*start)) {                                            \
      start++;                                                              \
    }                                                                       \
    /* skip to end of token */                                              \
    for (end = start; *end != '\0' && !fc_isspace(*end) && *end != ',';     \
         end++) {                                                           \
      /* nothing */                                                         \
    }                                                                       \
  }
 
/***********************************************************************/
static bool fc_has_capability(const char *cap, const char *capstr,
                              const size_t cap_len)
{
  const char *next;
 
  fc_assert_ret_val(capstr != NULL, FALSE);
 
  for (;;) {
    GET_TOKEN(capstr, next);
 
    if (*capstr == '+') {
      capstr++;
    }
 
    fc_assert(next >= capstr);
 
    if (((size_t)(next - capstr) == cap_len)
        && strncmp(cap, capstr, cap_len) == 0) {
      return TRUE;
    }
    if (*next == '\0') {
      return FALSE;
    }
 
    capstr = next + 1;
  }
}
 
/***********************************************************************/
bool has_capability(const char *cap, const char *capstr)
{
  return fc_has_capability(cap, capstr, strlen(cap));
}
 
/***********************************************************************/
bool has_capabilities(const char *us, const char *them)
{
  const char *next;
 
  for (;;) {
    GET_TOKEN(us, next);
 
    if (*us == '+' && !fc_has_capability(us+1, them, next-(us+1))) {
      return FALSE;
    }
    if (*next == '\0') {
      return TRUE;
    }
 
    us = next+1;
  }
}