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Wildcard string compare (globbing)

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4.90/5 (82 votes)
15 Feb 2005 1.1M   96   144
Matches a string against a wildcard string such as "*.*" or "bl?h.*" etc. This is good for file globbing or to match hostmasks.

Usage:

This is a fast, lightweight, and simple pattern matching function.

if (wildcmp("bl?h.*", "blah.jpg")) {
  //we have a match!
} else {
  //no match =(
}

Function:

int wildcmp(const char *wild, const char *string) {
  // Written by Jack Handy - <A href="mailto:jakkhandy@hotmail.com">jakkhandy@hotmail.com</A>
  const char *cp = NULL, *mp = NULL;

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

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

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

License

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Comments and Discussions

 
QuestionFastest wildcard function benchmarked with 3 compilers Pin
Sanmayce28-Nov-22 14:55
Sanmayce28-Nov-22 14:55 
QuestionMessage Closed Pin
17-Jun-21 14:45
Dayo Thomas17-Jun-21 14:45 
QuestionUnit tests please Pin
richarno2-Dec-19 22:03
richarno2-Dec-19 22:03 
Suggestionnice algorithm, but with a weakness Pin
senzabandiera7-Oct-16 23:24
senzabandiera7-Oct-16 23:24 
Generaldelphi port Pin
vovach77723-Dec-14 3:38
vovach77723-Dec-14 3:38 
QuestionMy vote of 5+ Pin
Sanmayce29-Nov-13 7:47
Sanmayce29-Nov-13 7:47 
GeneralMy vote of 5 Pin
Franc Morales29-May-13 15:47
Franc Morales29-May-13 15:47 
Questionhelp required for wilcard matching * and # Pin
SaimaAsif23-Feb-12 23:56
SaimaAsif23-Feb-12 23:56 
GeneralMy vote of 5 Pin
Plamen Petrov13-Dec-11 21:37
professionalPlamen Petrov13-Dec-11 21:37 
SuggestionModification with '#' as wildcard joker for digits Pin
Thomas Haase25-Sep-11 23:16
Thomas Haase25-Sep-11 23:16 
QuestionLicence Question Pin
randommark23-Nov-10 0:33
randommark23-Nov-10 0:33 
AnswerAnother C# version, with a twist Pin
Thomas Levesque29-Jun-10 14:50
professionalThomas Levesque29-Jun-10 14:50 
GeneralObscurity Pin
Chuck O'Toole25-Apr-10 18:18
Chuck O'Toole25-Apr-10 18:18 
AnswerMy C# contribution - recursive, of course! Pin
RenniePet26-Mar-10 5:21
RenniePet26-Mar-10 5:21 
This strikes me as an obvious place to use recursion. So here goes...

public class MString
{
   /// <summary>
   /// Function to compare two strings, where strA may contain wildcard characters '*' and
   /// '?'. http://en.wikipedia.org/wiki/Wildcard_character
   /// </summary>
   /// <param name="strA">string which may contain wildcards, may be empty, must not be null</param>
   /// <param name="strB">string to compare to, no wildcard processing, may be empty, must not be null</param>
   /// <param name="ignoreCase">true = ignore upper/lower case, false = don't ignore case</param>
   /// <returns>true = match, false = non-match</returns>
   public static bool CompareWWc(string strA, string strB, bool ignoreCase)
   {
      if (ignoreCase)
         return CompareWWc(strA.ToLower(), strB.ToLower());
      else
         return CompareWWc(strA, strB);
   }


   /// <summary>
   /// Recursive function to compare two strings, where strA may contain wildcard characters
   /// '*' and '?'. http://en.wikipedia.org/wiki/Wildcard_character
   /// </summary>
   /// <param name="strA">string which may contain wildcards, may be empty, must not be null</param>
   /// <param name="strB">string to compare to, no wildcard processing, may be empty, must not be null</param>
   /// <returns>true = match, false = non-match</returns>
   public static bool CompareWWc(string strA, string strB)
   {
      // Top of loop to scan across strA (and strB)
      for (int i = 0; i < strA.Length; i++)
      {
         // Special processing when we hit a '*' in strA
         if (strA[i] == '*')
         {
            // If the '*' is at the end of strA then result = true irrespective of strB
            if (i == strA.Length - 1)
               return true;

            // Do recursive calls to try to find a match somewhere to the right in strB
            strA = strA.Substring(i + 1);  // The part of strA beyond the '*'
            for (int j = i; j < strB.Length; j++)
               if (CompareWWc(strA, strB.Substring(j)))
                  return true;
            return false;
         }

         // Normal processing for non-'*' characters in strA
         if (i >= strB.Length || (strA[i] != strB[i] && strA[i] != '?'))
            return false;
      }

      // We've reached the end of strA and the last character is not '*'
      return strA.Length == strB.Length;
   }

}


And here's a little test sequence:

   if (!MString.CompareWWc("", ""))
      Console.WriteLine("Something wrong!");


   if (!MString.CompareWWc("something", "something"))
      Console.WriteLine("Something wrong!");

   if (MString.CompareWWc("something", "zomething"))
      Console.WriteLine("Something wrong!");

   if (MString.CompareWWc("something", "some"))
      Console.WriteLine("Something wrong!");

   if (MString.CompareWWc("something", "something else"))
      Console.WriteLine("Something wrong!");


   if (!MString.CompareWWc("s?m?th???", "something"))
      Console.WriteLine("Something wrong!");

   if (MString.CompareWWc("s?m?th???", "somethin"))
      Console.WriteLine("Something wrong!");


   if (!MString.CompareWWc("*", ""))
      Console.WriteLine("Something wrong!");

   if (!MString.CompareWWc("*", "nonsense"))
      Console.WriteLine("Something wrong!");

   if (!MString.CompareWWc("non*", "nonsense"))
      Console.WriteLine("Something wrong!");


   if (!MString.CompareWWc("*nonsense", "nonsense"))
      Console.WriteLine("Something wrong!");

   if (!MString.CompareWWc("non*nse", "nonsense"))
      Console.WriteLine("Something wrong!");

   if (MString.CompareWWc("non*nse", "nonsenze"))
      Console.WriteLine("Something wrong!");

   if (!MString.CompareWWc("non*n?e", "nonsense"))
      Console.WriteLine("Something wrong!");


   if (!MString.CompareWWc("n*on*nse", "nonsense"))
      Console.WriteLine("Something wrong!");

   if (!MString.CompareWWc("n*n*nse", "nonsense"))
      Console.WriteLine("Something wrong!");

   if (MString.CompareWWc("*non*nse", "nonsenze"))
      Console.WriteLine("Something wrong!");

   if (!MString.CompareWWc("n*n*n?e", "nonsense"))
      Console.WriteLine("Something wrong!");
}


By the way, the name CompareWWc means Compare With Wildcards.
GeneralRe: My C# contribution - recursive, of course! Pin
Erwin de GRoot29-Mar-10 1:58
Erwin de GRoot29-Mar-10 1:58 
GeneralDepends on whether you need to optimize the last few nanoseconds out of it... Pin
RenniePet29-Mar-10 7:45
RenniePet29-Mar-10 7:45 
GeneralSorry - revised numbers Pin
RenniePet29-Mar-10 8:35
RenniePet29-Mar-10 8:35 
GeneralRe: Depends on whether you need to optimize the last few nanoseconds out of it... Pin
Erwin de GRoot29-Mar-10 8:37
Erwin de GRoot29-Mar-10 8:37 
GeneralYet another version - 25% faster, I think [modified] Pin
RenniePet1-Apr-10 8:24
RenniePet1-Apr-10 8:24 
GeneralRe: Yet another version - 25% faster, I think Pin
aleks1k21-Sep-11 2:47
aleks1k21-Sep-11 2:47 
QuestionI used this function but I how I can catch variables from the * ??? Pin
moh.hijjawi20-Oct-09 1:55
moh.hijjawi20-Oct-09 1:55 
AnswerRe: I used this function but I how I can catch variables from the * ??? Pin
RenniePet1-Apr-10 11:27
RenniePet1-Apr-10 11:27 
Questionany updates ? Pin
kiquenet.com2-Jul-09 5:12
professionalkiquenet.com2-Jul-09 5:12 
GeneralImproved matching with end-of-text Pin
Anders Heie11-May-09 15:20
Anders Heie11-May-09 15:20 
GeneralRe: Improved matching with end-of-text: some cases don't work properly! Pin
roadrunner31412-Aug-09 3:35
roadrunner31412-Aug-09 3:35 

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