C++:不区分大小写的first-n-characters字符串比较

Question

我的问题与此类似,但我有两个字符串(as char *),任务是strnicmp用类似的东西替换函数(仅适用于MS VC)boost::iequals.

注意strnicmp不是stricmp- 它只比较前n个字符.

有没有比这更简单的解决方案:

void foo(const char *s1, const char *s2) 
{
    ...

    std::string str1 = s1;
    std::string str2 = s2;
    int n = 7;

    if (boost::iequals(str1.substr(0, n), str2)) {
        ...
    }
}

Answer 1

如果确实有必要,请编写自己的函数:

bool mystrnicmp(char const* s1, char const* s2, int n){
  for(int i=0; i < n; ++i){
    unsigned char c1 = static_cast<unsigned char>(s1[i]);
    unsigned char c2 = static_cast<unsigned char>(s2[i]);
    if(tolower(c1) != tolower(c2))
      return false;
    if(c1 == '\0' || c2 == '\0')
      break;
  }
  return true;
}