Wildcard string compare (globbing)

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

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

About the Author

Jack Handy

Web Developer

United States

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Comments and Discussions

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Re: PathMatchSpec instead?

MandatoryDefault

10:39 31 Aug '09

I recommend against PathMatchSpec(). I used that function in my own code and it just bit me. Its wildcard behavior is broken for all but the simplest cases. For example, these two commands incorrectly return false: `::PathMatchSpec("C:\\Windows", "C:\\Windows.*");` `::PathMatchSpec("C:\\Windows", "C:\\Windows.");`
Sign In·View Thread·Permalink	1.00/5 (1 vote)

wchar_t version?

rmorales87

20:16 29 Nov '08

Anyone tried converting this to using wchar_t* (essentially Unicode) instead of char*?
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Re: wchar_t version?

razvar

21:49 31 Mar '11

This is great and got my 5 because is simple, fast and useful!

Here is the wchar_t version:

int wildcmp(const wchar_t *wild, const wchar_t *string)
  {
  const wchar_t *cp = NULL, *mp = NULL;
 
  while ((*string) && (*wild != L'*')) {
    if ((towlower(*wild) != towlower(*string)) && (*wild != L'?')) {
      return 0;
    }
    wild++;
    string++;
  }
 
  while (*string) {
    if (*wild == L'*') {
      if (!*++wild) {
        return 1;
      }
      mp = wild;
      cp = string+1;
    } else if ((towlower(*wild) == towlower(*string)) || (*wild == L'?')) {
      wild++;
      string++;
    } else {
      wild = mp;
      string = cp++;
    }
  }
 
  while (*wild == L'*') {
    wild++;
  }
  return !*wild;
}

Example:

if (wildcmp(L"*bl?h.*", L"asblah.plm")) {
  //we have a match!
   MessageBox(0,"we have a match!","wildcmp wide",MB_TOPMOST);
} else {
  //no match =(
      MessageBox(0,"no match!","wildcmp wide",MB_TOPMOST);
}

wildcmp in XBLite

CodeGibbon

13:56 27 Nov '08

This is the version of the wildcmp function in XBLite programming language:

FUNCTION SBYTE wildcmp( wildcard$, search$)
  ' wildcmp(const char *wild, const char *string)
  ' Written by Jack Handy - jakkhandy@hotmail.com
 
  ULONG cp
  ULONG mp
  
  STRING s_txt$
  ULONG  sp 
  
  STRING w_txt$
  ULONG  wp
 
  IFZ search$   THEN RETURN $$FALSE  
  IFZ wildcard$ THEN RETURN $$FALSE
  
  w_txt$ = wildcard$ + "\0\0"   ' Just to be sure
  s_txt$ = search$   + "\0\0"
  
  DO WHILE (s_txt${sp}) && (w_txt${wp} != '*') 
    IF (w_txt${wp} != s_txt${sp} )  && (w_txt${wp} != '?') THEN RETURN $$FALSE
    
    INC wp
    INC sp
  LOOP
    
  DO WHILE (s_txt${sp})
    IF ( w_txt${wp} == '*' ) THEN    
      INC wp
      IF !(w_txt${wp}) THEN RETURN $$TRUE      
      
      mp = wp     
      cp = sp + 1 
    ELSE 
      IF (w_txt${wp} == s_txt${sp} )  || (w_txt${wp} == '?') THEN    
        INC wp
        INC sp
      ELSE
        wp = mp
      
        sp = cp                   
        IF s_txt${sp} THEN INC cp 
       
      ENDIF
    ENDIF  
  LOOP
    
  DO WHILE (w_txt${wp} == '*' )    
    INC wp
  LOOP
  
  RETURN !w_txt${wp} 
 
END FUNCTION

Wildcard string compare in C#

haiquang

22:15 10 Nov '08

I had converted the wildcmp to C#, it's very easy to wildcard string, thanks so much.

bool WildCompare(string strWild, string strEmail)
{
int cp = 0;
int mp = 0;

int wildIndex = 0;
int emailIndex = 0;

while ((!ValueIsNullOrEmpty(strEmail, emailIndex)) && (ValueAt(strWild, wildIndex) != '*'))
{
if ((ValueAt(strWild, wildIndex) != ValueAt(strEmail, emailIndex)) && (ValueAt(strWild, wildIndex) != '?'))
{
return false;
}
wildIndex++;
emailIndex++;
}

while (!ValueIsNullOrEmpty(strEmail,emailIndex))
{
if (ValueAt( strWild, wildIndex) == '*')
{
wildIndex++;
if (ValueIsNullOrEmpty(strWild,wildIndex ))
{
return true;
}
mp = wildIndex;
cp = emailIndex + 1;
}
else if ((ValueAt(strWild, wildIndex).Equals(ValueAt(strEmail, emailIndex)) || (ValueAt(strWild, wildIndex) == '?')))
{
wildIndex++;
emailIndex++;
}
else
{
wildIndex = mp;
emailIndex = cp++;
}
}

while (ValueAt(strWild, wildIndex) == '*')
{
wildIndex++;
}
return ValueIsNullOrEmpty(strWild, wildIndex);
}

Cry | :((

Re: Wildcard string compare in C#

haiquang

22:22 3 Aug '09

is it good converted? Take SharePoint to new height
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C# Direct Port

hempels

15:10 23 Sep '08

Well, as direct as I could come up with anyway. Makes use of unsafe to enable pointer arithmetic. Unfortunately, because fixed is required to prevent the GC from moving the pointers, I had to change it to use increment indexers instead of directly manipulating the pointers. Alternatively, you could use stackalloc to instantiate two native char[]'s and copy the values, but that seems contrary to this function's low-memory footprint, high performance goals.

Has been tested against every test case presented in the comments section as well as some additional cases I threw in.

public unsafe static bool GlobCompare( string glob, string path )
{
      fixed ( char* pGlob = glob, pPath = path )
      {
            int pGlobInc = 0;
            int pPathInc = 0;

            int mp = 0;
            int cp = 0;

            while ( ( *( pPath + pPathInc ) != 0 ) && ( *( pGlob + pGlobInc ) != '*' ) )
            {
                  if ( ( *( pGlob + pGlobInc ) != *( pPath + pPathInc ) ) && ( *( pGlob + pGlobInc ) != '?' ) )
                  {
                        return false;
                  }
                  pGlobInc++;
                  pPathInc++;
            }

            while ( *( pPath + pPathInc ) != 0 )
            {
                  if ( *( pGlob + pGlobInc ) == '*' )
                  {
                        if ( 0 == *( pGlob + ++pGlobInc ) )
                        {
                              return true;
                        }
                        mp = pGlobInc;
                        cp = pPathInc + 1;
                  }
                  else if ( ( *( pGlob + pGlobInc ) == *( pPath + pPathInc ) ) || ( *( pGlob + pGlobInc ) == '?' ) )
                  {
                        pGlobInc++;
                        pPathInc++;
                  }
                  else
                  {
                        pGlobInc = mp;
                        pPathInc = cp++;
                  }
            }

            while ( *( pGlob + pGlobInc ) == '*' )
            {
                  pGlobInc++;
            }
            return ( 0 == *( pGlob + pGlobInc ) );
      }
}

...and yet another C# port [modified]

DVF

16:59 27 Aug '10

public static bool WildcardMatch(string strCompare, string strWild, bool bIgnoreCase)
{
    if (bIgnoreCase)
    {
        strWild = strWild.ToUpper();
        strCompare = strCompare.ToUpper();
    }
 
    // Lengths of strings
    int iWildLen = strWild.Length;
    int iCompareLen = strCompare.Length;
 
    // Used to save position when '*' found in strWild
    // Initialized to invalid values
    int iWildMatched = iWildLen;
    int iCompareBase = iCompareLen;
 
    int iWild = 0;
    int iCompare = 0;
 
    // Match until first wildcard '*'
    while (iCompare < iCompareLen && (iWild >= iWildLen || strWild[iWild] != '*'))
    {
        if (iWild >= iWildLen || (strWild[iWild] != strCompare[iCompare] && strWild[iWild] != '?'))
            return false;
 
        iWild++;
        iCompare++;
    }
 
    // Process wildcard
    while (iCompare < iCompareLen)
    {
        if (iWild < iWildLen)
        {
            if (strWild[iWild] == '*')
            {
                iWild++;
 
                if (iWild == iWildLen)
                    return true;
 
                iWildMatched = iWild;
                iCompareBase = iCompare + 1;
 
                continue;
            }
 
            if (strWild[iWild] == strCompare[iCompare] || strWild[iWild] == '?')
            {
                iWild++;
                iCompare++;
 
                continue;
            }
        }
 
        iWild = iWildMatched;
        iCompare = iCompareBase++;
    }
 
    while (iWild < iWildLen && strWild[iWild] == '*')
        iWild++;
 
    if (iWild < iWildLen)
        return false;
 
    return true;
}

modified on Saturday, August 28, 2010 10:10 PM

Re: ...and yet another C# port

VUnreal

11:22 21 Sep '10

Works quite well.
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[Message Removed]

stonber

14:22 18 Sep '08

Spam message removed
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Using in Artistic Style

jimp02

4:43 3 Apr '08

I am using this in Artistic Style, a popular multi-platform code formatter available at SourceForge.

http://astyle.sourceforge.net/

Release 1.22 added directory recursion to the project. Wildcard processing was made internal to the program. Linux has a glob function but Windows doesn't. I just used this for both of them. It let me process both platforms in a similar manner.

A minor change was made for Windows to make the comparison case insensitive. Linux was left case sensitive.

Thanks for making it available. Using this was a lot easier than writing my own. I doubt that mine would have been this sophisticated.

Geez...

larryfr

9:39 5 Mar '08

Boy do I feel stupid. I worked on an algorithm like this for days, and never got it quite right. Then, I see the wonderful, and simplistic work of someone like this, and it reminds me that sometimes we all are guilty of 'over-engineering'... Thanks Mr. Handy!
Sign In·View Thread·Permalink	3.00/5 (3 votes)

Convert to a replace?

williaps

8:31 20 Mar '07

How can this code be converted to do a replace? I need to provide a find/replace dialog in an application and I don't want to jump through the hoops of the Boost library. Can anyone help? Patrick
Sign In·View Thread·Permalink	2.00/5 (1 vote)

C# RexExp version

spinsane

6:30 4 Nov '06

Here's RegExp version (may be easily ported to C++).
Pros: More readable, Relies on proven RegExp
Cons: Maybe slower?, If eval string contains RegExp keywords then it might result in unexpected result



public static bool Match(string eval, string pattern, bool caseSensitive)

{

	bool match = false;

 

	// Make input parameters lower-case if case is not an issue

	if (!caseSensitive)

	{

		eval = eval.ToLower();

		pattern = pattern.ToLower();

	}

 

	// Escape regexp special character in pattern

	pattern = pattern.Replace(".", @"\.");

 

	// Replace valid wildcards with regexp equivalents

	pattern = pattern.Replace('?', '.').Replace("*", ".*");

 

	// Add boundaries to pattern

	pattern = @"\A" + pattern + @"\z";

 

	// Search for a match

	try

	{

		match = Regex.IsMatch(eval, pattern);

	}

	catch /* (ArgumentException ex) */

	{

		// Syntax error in the regular expression

	}

 

	// Return result

	return match;

}

Kudos

quantumred

4:37 14 Oct '06

This is tight and clever. Thanks for sharing it.
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Re: Kudos

milkplus

11:19 24 Feb '10

I agree. This is excellent.
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wildcmp("*<*>", "<field1><field2>") not working [modified]

Daniel B.

13:14 6 Sep '06

Hi, wildcmp("<>", "<field1><field2>") return 1 while I think it should return 0 (I maybe wrong, so please tell me). If someone knows how to fix it, I will appreciate. Regards
Sign In·View Thread·Permalink	1.00/5 (1 vote)

Re: wildcmp("*<*>", "<field1><field2>") not working

radboudp

0:35 16 Feb '07

Sure it matches. The first '' matches ''. '<>' matches '' Regards, Radboud
Sign In·View Thread·Permalink	4.00/5 (2 votes)

return value type

wdx04

15:49 8 Jan '06

I think it's better to make the function return a bool value. Anyway, many string comparision functions return 0 when the strings equal.
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*? case match

talimu

23:42 3 Nov '05

if wild = "?.abc", str = "abc.abc" wildcmp(wild, str) not work but if wild = "?.abc", str = "abc.abc" wildcmp(wild, str) do work does anyone have any idea about the case?
Sign In·View Thread·Permalink	3.50/5 (2 votes)

Re: *? case match

kuhnm

2:18 15 Sep '06

Having similar problems with "Hallo 200? ueberalles.ddd". It doesn´t work. I think, when the first * is finished, it does not expect an other wildcard in the pattern to follow.
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Re: *? case match

kuhnm

4:48 18 Sep '06

Ignore my last email, like usually the problem sits in front of the screen. (I mixed a project built with multibyte Chars with this code which was only chars. And of course I used a Umlaut instead of 'ue' in my tests. So no wonder, why it crashed after the '?' ) I´m very sorry!
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Gets my 5

Franc Morales

17:05 18 Oct '05

Simple, fast, useful, AND fun to figure out. Well done.
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mp and cp

twopieman

11:59 15 Mar '05

i got the overall flow of the program I didnt get the logic of the second loop completely. I understand that in the second loop it checks if there is nothing after * if so then it is a match but if there is something it stores them in the two pointers and then goes on.
also in the final else it goes like else
{
wild = mp;
string = cp++;
}
am sorry but am not getting the logic totally.
can someone please explain?

Re: mp and cp

radboudp

1:14 16 Feb '07

In case you are matching something like the following:

"*.abc" to "ab.de.abc"

In the second loop it looks for the first character after the asterisk that is the same in the string. At first it matches "*" against "ab". mp = ".abc" during this. Now wild = ".abc" and string = ".de.abc". Obvious no match. On the next loop the first characters do match (both '.') and wild becomes "abc" and string "de.abc". The next loop there is no match and it falls to the else. Here it resets wild to the last mp (mask pattern??) and string to the last cp (character pattern) WITHOUT THE FIRST CHARACTER. (It actually advances cp one position.)

Why does it do this. After matching the * against part of the string and encountering a possible poisiton where to match the remainder of the pattern, it continued comparing characters from both to each other. This fialed. Since right before the position of mp there was a *, it is still allowed to add characters to the part that is matched against that. Basically, it goes back to that position but decides that the character that occurs in both strings is not the next character in the pattern but part of the '*' wildcard.

In the end it has matched '*' with 'ab.de'.