C语言通配符匹配

C语言通配符匹配

工作中经常会遇到通配符，windows控制台程序，linux shell，还有web服务器配置路径，Makefile中。

我来分享两个C语言通配符匹配程序和测试程序；我是抱着拿来主义的想法，年纪大了越越懒得动脑子了。

通配符程序中用到的是*和?

*表示任意多个任意字符

?表示单个任意字符

关于通配符的定义引用百度百科的一段话

通配符是一种特殊语句，主要有星号(*)和问号(?)，用来模糊搜索文件。当查找文件夹时，可以使用它来代替一个或多个真正字符；当不知道真正字符或者懒得输入完整名字时，常常使用通配符代替一个或多个真正的字符。 实际上用”*Not?paOd”可以对应Notpad\MyNotpad【*可以代表任何文字】;Notpad\Notepad【?仅代表单个字】;Notepad\Notepod【ao代表a与o里二选一】，其余以此类推。

第一个程序是商业友好的license，请放心使用！

License

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第二个没有明确标明。

两个程序是类似的，第一个程序用的是循环，第二个程序用的是递归。

static int wildcmp(const char* wild, const char* pattern)
{
  // Written by Jack Handy - <A href="mailto:[email protected]">[email protected]</A>
  const char *cp = NULL, *mp = NULL;

  while ((*pattern) && (*wild != '*')) 
  {
    if ((*wild != *pattern) && (*wild != '?')) 
    {
      return 0;
    }
    wild++;
    pattern++;
  }

  while (*pattern) 
  {
    if (*wild == '*') 
    {
      if (!*++wild) 
      {
        return 1;
      }
      mp = wild;
      cp = pattern + 1;
    }
    else if ((*wild == *pattern) || (*wild == '?')) 
    {
      wild++;
      pattern++;
    }
    else
    {
      wild = mp;
      pattern = cp++;
    }
  }

  while (*wild == '*') 
  {
    wild++;
  }
  return !*wild;
}


// The main function that checks if two given strings match. The first
// string may contain wildcard characters
static bool match(const char *first,  const char* second)
{
  // If we reach at the end of both strings, we are done
  if (*first == '\0' && *second == '\0')
    return true;

  // Make sure that the characters after '*' are present in second string.
  // This function assumes that the first string will not contain two
  // consecutive '*' 
  if (*first == '*' && *(first + 1) != '\0' && *second == '\0')
    return false;

  // If the first string contains '?', or current characters of both 
  // strings match
  if (*first == '?' || *first == *second)
    return match(first + 1, second + 1);

  // If there is *, then there are two possibilities
  // a) We consider current character of second string
  // b) We ignore current character of second string.
  if (*first == '*')
    return match(first + 1, second) || match(first, second + 1);
  return false;
}

// A function to run test cases
static void test(const char* first, const char* second)
{
  match(first, second) ? puts("Yes") : puts("No");
}

static void test2(const char* first, const char* second)
{
  wildcmp(first, second) ? puts("Yes") : puts("No");
}

int _tmain(int argc, _TCHAR* argv[])
{
  test("g*ks", "geeks"); // Yes
  test("ge?ks*", "geeksforgeeks"); // Yes
  test("g*k", "gee");  // No because 'k' is not in second
  test("*pqrs", "pqrst"); // No because 't' is not in first
  test("abc*bcd", "abcdhghgbcd"); // Yes
  test("abc*c?d", "abcd"); // No because second must have 2 instances of 'c'
  test("*c*d", "abcd"); // Yes
  test("*?c*d", "abcd"); // Yes

  puts("==================================\n");

  test2("g*ks", "geeks"); // Yes
  test2("ge?ks*", "geeksforgeeks"); // Yes
  test2("g*k", "gee");  // No because 'k' is not in second
  test2("*pqrs", "pqrst"); // No because 't' is not in first
  test2("abc*bcd", "abcdhghgbcd"); // Yes
  test2("abc*c?d", "abcd"); // No because second must have 2 instances of 'c'
  test2("*c*d", "abcd"); // Yes
  test2("*?c*d", "abcd"); // Yes

  return 0;
}

测试结果:

参考链接：

http://www.codeproject.com/Articles/1088/Wildcard-string-compare-globbing

http://www.geeksforgeeks.org/wildcard-character-matching/#