Hey All
This code is for matching a string with a wildcard in it to another string. If you want to have a Astrix in the first string be counted as a character and not as a wildcard put a \ in front of it. I have tested it for quite a few different possibilities and it has worked for what I have tested it with. Include is a short main function demonstrating it working. Fell free to use it if you want but I CAN'T guarantee that it is bug free.
Nathan
// WildcardCompare.h
#ifndef WILDCARDCOMPARE_H
#define WILDCARDCOMPARE_H
#include <string>
#include <vector>
bool WildcardCompare(std::string searchTerm, std::string checkAgaints)
{
bool found = false;
std::vector<std::string> parts;
std::string temp;
if (searchTerm == "*")
return true;
if (searchTerm.size() - 1 > checkAgaints.size())
return false;
std::string::const_iterator it = searchTerm.begin(), end = searchTerm.end();
size_t counter = 0;
while (it != end)
{
if (*it != '*')
temp += *it;
if (*it == '*')
{
parts.push_back(temp);
temp = "";
}
it++;
}
parts.push_back(temp);
std::vector<std::string>::const_iterator vecIt = parts.begin(), vecEnd = parts.end();
if (!parts[0].empty())
{
if (parts[0] != checkAgaints.substr(0, parts[0].size()))
return false;
}
else
vecIt++;
size_t size = checkAgaints.size();
size_t pos = 0;
size_t tempSize;
while (vecIt != vecEnd)
{
temp = *vecIt;
tempSize = temp.size();
if (temp.empty())
return true;
while (pos + tempSize < size)
{
if (temp == checkAgaints.substr(pos, temp.size()))
{
checkAgaints.erase(0, pos + temp.size());
found = true;
break;
}
pos++;
}
if (found == false)
return false;
pos = 0;
vecIt++;
}
return true;
}
#endif
// main.cpp
#include <iostream>
#include "WildcardCompare.h"
int main()
{
std::string searchFor = "*my*day.*";
std::string word = "this is my good day.txt";
if (WildcardCompare(searchFor, word))
std::cout << "works";
else
std::cout << "doesnt work";
searchFor = "*my\*day.*";
word = "my*day.txt";
if (WildcardCompare(searchFor, word))
std::cout << "works";
else
std::cout << "doesnt work";
std::cin.get();
return 0;
}
>> searchFor = "*my\*day.*";
That will not compile -- if you want a \ in the string then you have to put two of them, so the code should be searchFor = "*my\\*day.*"; Otherwise the program appears to work ok for the tests I made. Now I think you should improve the program by allowing ? as a wild card that matches just a single character.
Very useful, thank you :)
I think there is some problems..
I tried the escaping of asterisk - didn't seem to work.
I tried to searchFor "*.php" and set word to "MyScript.php" - returned false.
Thank you AD for your reply. The single slash in my code was a typo. As for having a ? act as a any single letter I am implementing that right now and I should have it finished shortly. I'll post the updated code once its done.
@ Excizted I fixed what was causing the problem and when I post the updated code "*.php" for searchFor and "MyScript.php" for word will work.
Okay well I believe I have it all sorted out. I added using a ? as a single letter wildcard and it appears to work just fine. I wound up having to write another function that compared 2 strings if one had a ? in it. I just went through the string that had the ?'s in it and where ever there was a ? i replaced it with the letter in the second string at that same spot. The main function has not changed from my first post so I will just post my new WildcardCompare.h. If anyone else finds something it doesn't work for or isn't right let me know so i can try and fix it. Thanks.
test cases
"*this*my*\\**da?.php"
against
"this is my *good day.php"
outcome
true
"???.txt"
against
"bad.txt"
outcome
true
"\\*.txt"
against
"8.txt"
outcome
true
and lastly
"*.php"
against
"MyScript.php"
outcome
true#ifndef WILDCARDCOMPARE_H
#define WILDCARDCOMPARE_H
#include <string>
#include <vector>
bool SingleWildcardMatch(std::string, std::string);
bool WildcardCompare(std::string searchTerm, std::string checkAgaints)
{
bool found = false;
std::vector<std::string> parts;
std::string temp;
if (searchTerm == "*")
return true;
if (searchTerm.size() - 1 > checkAgaints.size())
return false;
std::string::const_iterator it = searchTerm.begin(), end = searchTerm.end();
size_t counter = 0;
while (it != end)
{
if (*it == '*')
{
parts.push_back(temp);
temp = "";
it++;
continue;
}
if (*it == '\\' && *(++it) == '*')
{
temp += "*";
it++;
continue;
}
temp += *it;
it++;
}
parts.push_back(temp);
bool singleWildcardPresent = false;
if(temp.find_first_of("?",0) != std::string::npos)
singleWildcardPresent = true;
std::vector<std::string>::const_iterator vecIt = parts.begin(), vecEnd = parts.end();
if (!parts[0].empty() && !singleWildcardPresent)
{
if (parts[0] != checkAgaints.substr(0, parts[0].size()))
return false;
}
if (!parts[0].empty() && singleWildcardPresent)
{
if (!SingleWildcardMatch(parts[0], checkAgaints.substr(0, parts[0].size())))
return false;
}
else
vecIt++;
size_t size = checkAgaints.size();
size_t pos = 0;
size_t tempSize;
while (vecIt != vecEnd)
{
temp = *vecIt;
tempSize = temp.size();
if (temp.empty())
return true;
while (pos + tempSize <= size)
{
if (singleWildcardPresent)
{
if (SingleWildcardMatch(temp, checkAgaints.substr(pos, temp.size())))
{
checkAgaints.erase(0, pos + temp.size());
found = true;
break;
}
}
else
{
if (temp == checkAgaints.substr(pos, temp.size()))
{
checkAgaints.erase(0, pos + temp.size());
found = true;
break;
}
}
pos++;
}
if (found == false)
return false;
pos = 0;
vecIt++;
}
return true;
}
bool SingleWildcardMatch(std::string first, std::string second)
{
if (first.size() != second.size())
return false;
std::string::iterator firstIt = first.begin(), firstEnd = first.end();
std::string::const_iterator secondIt = second.begin();
while (firstIt != firstEnd)
{
if (*firstIt == '?')
*firstIt = *secondIt;
firstIt++;
secondIt++;
}
if (first == second)
return true;
return false;
}
#endif
One problem with this code is that it can't match a literal '?'. Another is its complexity. I can't even try to understand how it works, let alone debug it.
This is how I would approach globbing:
#include "glob.h"
int globMatch(char * pattern, char * text)
{
while(*pattern && *text) {
char p = *pattern++;
switch(p) {
case '*':
while(*text) {
int rc = globMatch(pattern, text++);
if(rc != MATCH_FAIL)
return rc;
}
return MATCH_FAIL;
case '\\':
if((p = *pattern++) == 0)
return MATCH_ERROR;
if(p != *text++)
return MATCH_FAIL;
break;
case '?':
text++;
break;
default:
if(p != *text++)
return MATCH_FAIL;
}
}
return ((*pattern == 0) && (*text == 0))? MATCH_SUCCESS: MATCH_FAIL;
}with an obvious glob.h:
#ifndef _GLOB_H_
#define _GLOB_H_
#define MATCH_ERROR -1
#define MATCH_SUCCESS 0
#define MATCH_FAIL 1
#ifdef cplusplus
extern "C" {
#endif
int globMatch(char * pattern, char * text);
#ifdef cplusplus
}
#endif
#endifOne problem with this code is that it can't match a literal '?'. Another is its complexity. I can't even try to understand how it works, let alone debug it.
This is how I would approach globbing:#include "glob.h" int globMatch(char * pattern, char * text) { while(*pattern && *text) { char p = *pattern++; switch(p) { case '*': while(*text) { int rc = globMatch(pattern, text++); if(rc != MATCH_FAIL) return rc; } return MATCH_FAIL; case '\\': if((p = *pattern++) == 0) return MATCH_ERROR; if(p != *text++) return MATCH_FAIL; break; case '?': text++; break; default: if(p != *text++) return MATCH_FAIL; } } return ((*pattern == 0) && (*text == 0))? MATCH_SUCCESS: MATCH_FAIL; }with an obvious glob.h:
#ifndef _GLOB_H_ #define _GLOB_H_ #define MATCH_ERROR -1 #define MATCH_SUCCESS 0 #define MATCH_FAIL 1 #ifdef cplusplus extern "C" { #endif int globMatch(char * pattern, char * text); #ifdef cplusplus } #endif #endif
Very interesting code.
I tried it out and with simple things it worked, eg. "Hello.*" will match "Hello.cpp".
What doesn't work is "MyFile*.mat.*" trying to match "MyFileForComputers.mat.php" which obviously should match.
Otherwise that is a nice approach.
Okay well I believe I have it all sorted out. I added using a ? as a single letter wildcard and it appears to work just fine. I wound up having to write another function that compared 2 strings if one had a ? in it. I just went through the string that had the ?'s in it and where ever there was a ? i replaced it with the letter in the second string at that same spot. The main function has not changed from my first post so I will just post my new WildcardCompare.h. If anyone else finds something it doesn't work for or isn't right let me know so i can try and fix it. Thanks.
test cases"*this*my*\\**da?.php" against "this is my *good day.php" outcome true "???.txt" against "bad.txt" outcome true "\\*.txt" against "8.txt" outcome true and lastly "*.php" against "MyScript.php" outcome true#ifndef WILDCARDCOMPARE_H #define WILDCARDCOMPARE_H #include <string> #include <vector> bool SingleWildcardMatch(std::string, std::string); bool WildcardCompare(std::string searchTerm, std::string checkAgaints) { bool found = false; std::vector<std::string> parts; std::string temp; if (searchTerm == "*") return true; if (searchTerm.size() - 1 > checkAgaints.size()) return false; std::string::const_iterator it = searchTerm.begin(), end = searchTerm.end(); size_t counter = 0; while (it != end) { if (*it == '*') { parts.push_back(temp); temp = ""; it++; continue; } if (*it == '\\' && *(++it) == '*') { temp += "*"; it++; continue; } temp += *it; it++; } parts.push_back(temp); bool singleWildcardPresent = false; if(temp.find_first_of("?",0) != std::string::npos) singleWildcardPresent = true; std::vector<std::string>::const_iterator vecIt = parts.begin(), vecEnd = parts.end(); if (!parts[0].empty() && !singleWildcardPresent) { if (parts[0] != checkAgaints.substr(0, parts[0].size())) return false; } if (!parts[0].empty() && singleWildcardPresent) { if (!SingleWildcardMatch(parts[0], checkAgaints.substr(0, parts[0].size()))) return false; } else vecIt++; size_t size = checkAgaints.size(); size_t pos = 0; size_t tempSize; while (vecIt != vecEnd) { temp = *vecIt; tempSize = temp.size(); if (temp.empty()) return true; while (pos + tempSize <= size) { if (singleWildcardPresent) { if (SingleWildcardMatch(temp, checkAgaints.substr(pos, temp.size()))) { checkAgaints.erase(0, pos + temp.size()); found = true; break; } } else { if (temp == checkAgaints.substr(pos, temp.size())) { checkAgaints.erase(0, pos + temp.size()); found = true; break; } } pos++; } if (found == false) return false; pos = 0; vecIt++; } return true; } bool SingleWildcardMatch(std::string first, std::string second) { if (first.size() != second.size()) return false; std::string::iterator firstIt = first.begin(), firstEnd = first.end(); std::string::const_iterator secondIt = second.begin(); while (firstIt != firstEnd) { if (*firstIt == '?') *firstIt = *secondIt; firstIt++; secondIt++; } if (first == second) return true; return false; } #endif
Indeed this code is a bit complex.
It seems to work in many cases, I did find one that doesn't work though.
Let me try to reproduce it with a test string.
Edit: "D?or*.material" against "Door424.material" returns false.
Ill look into it later today and see what's goimg on
And this is why kids, building a regular expression function is so damn hard.
@ Zoon - The first example you posted with "MyFile*.mat.*" against "MyFileForComputers.mat.php" worked fine with the code I have. The second example you posted with "D?or*.material" against "Door424.material" did return false and it was a variable name error. On line 40 of my second code post it should be
if(parts[0].find_first_of("?",0) != std::string::npos)Thanks for catching that.
@ nezachem - I understand it might look a little complex but it is pretty self explanatory. I went the STL route and that sometimes make it look a little more complicated. Also I wanted to try and solve this without using recursion.
I will work on adding support for having a ? be a ? as well. Not sure if I'll get to it today though. I'm attaching the updated code this time instead of posting it to save space.
Well I think I have a solution now that will allow the user to \? to have that be an actual ?. I had to change my approach a little bit and added a couple new functions but it works for the test cases I have tried. I'm just attaching the code again.
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