Thread: wildcard system

i need help making a wildcarding system

so far ive checked if hters a wildcard in the front, and the back. thats all i want for now
then after that, i dont know. lol. i guess if theres a wildcard in the front, get the last word (or bunch), if theres one in the back, compare the first word (or bunch), and on both sides just find the string in it

whats confusing me is:
if i have
*hello
and i type in
i say hello

do i just extract everything from the * to the end, and then, reverse the string i say (i say hello, reverse that), and compare it backwards untill the pattern string is done?

any other ideas?

ok heres my code, works for the most part i guess

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>

int main(int argc, char *argv[]){
	char *pattern = new char[255];
	char *patcpy = new char[255];
	char *patcheck = new char[255];
	
	//wildcard locations
	bool wcfront=false;
	bool wcback=false;
	bool found=true;

	strcpy(pattern,"");
	strcpy(patcheck,"");

	printf("Enter pattern (eg, *hello): ");
	gets(pattern);
	printf("Enter string to check pattern against: ");
	gets(patcheck);

	//get wildcard in front 
	//strcpy(patcpy,pattern);
	while(strlen(pattern)){
		if(*pattern == '*'){
			*pattern++;
			wcfront=true;
			break;
		}
		else if(*pattern!=' ' && *pattern!='*'){
			break;
		}
		else{
			*pattern++;
		}
	}

	//wildcard in back, strip it off
	pattern=strrev(pattern);
	while(strlen(pattern)){
		if(*pattern=='*'){
			*pattern++;
			wcback=true;
			break;
		}
		else if(*pattern!=' ' && *pattern!='*'){
			break;
		}
		else {
			*pattern++;
		}
	}
	pattern=strrev(pattern);

	if(wcfront && wcback){
		if(strncmp(pattern,patcheck,strlen(pattern))!=0){
			printf("Pattern found in front and back");
		}
	}
	else if(wcfront){
		patcheck = strrev(patcheck);
		pattern = strrev(pattern);
		while(strlen(pattern) && strlen(patcheck)){
			if(*patcheck != *pattern){
				found=false;
				break;
			}
			*pattern++;
			*patcheck++;
		}

		if(found){
			printf("Pattern found in front");
		}
	}
	else if(wcback){
		while(strlen(pattern) && strlen(patcheck)){
			if((*patcheck != *pattern)){
				found=false;
				break;
			}
			*pattern++;
			*patcheck++;
		}

		if(found){
			printf("Pattern found in back");
		}
	}
	else {
		if(!strcmp(pattern,patcheck)){
			printf("They are equal");
		}
		else {
			printf("No match");
		}
	}

	int blah=getch();
		
	return 1;
}

i tested it a bunch, anyone found any errors or things i can do to make it more effecient?

Here's a function:

Code:

bool match(const char *mask, const char *s)
{
  const char     *sNote;          
  const char     *mNote = 0;                                    
  for (;;)
  {
    if (! *s)
    {
      while (*mask == '*')
        ++mask;
      return ! *mask;
    }
    if (*mask == '*')
    {
      if (! *++mask)
        return true
      mNote = mask;
      sNote = s + 1;
      continue;
    }
    if (*mask == *s || *mask == '?')
    {
      ++mask, ++s;
      continue;
    }
    if (! mNote)
    	return false;
    mask = mNote;
    s = sNote++;       
  }
}

it returns true if the mask (with * and ?) matches the string.

BTW, do you want a function for approximate matching too? I wrote one the other day.

wow thats super short..lol..trying to understand it. mask is the pattern and s is the string itself?

also, whats the ? for

and yeah, sure, thanks

The ? matches any character.

"pe???r" matches "petter" but not "peter"
"pet*r" matches both

oic, gotcha thanks