write functions with pointers variables

This is a discussion on write functions with pointers variables within the C Programming forums, part of the General Programming Boards category; Hi all, I have trouble with the below function: int suffix_searching(char*str, int len, char*suffix); The function copies the suffix of ...

  1. #1
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    write functions with pointers variables

    Hi all,

    I have trouble with the below function:

    int suffix_searching(char*str, int len, char*suffix);

    The function copies the suffix of length len of string str into string suffix and returns 1 if len is smaller than or equal to the length of str; returns 0 without copying if len is larger than the length of str

    Thanks

  2. #2
    Woof, woof! zacs7's Avatar
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    Fantastic, care elaborating?

  3. #3
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    Perhaps something like this or shed more light on the problem using code or pseudo-code.
    Code:
    int suffix_searching(char *str, int len, char *suffix)
    {
        int nc = 0;
    
        if (len <= strlen(str)) {
            while (*suffix++ = *str++) {
                if (++nc >= len)
                    break;
            }
            return 1;
        }
        return 0;
    }

  4. #4
    Banned master5001's Avatar
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    I posted code that does exactly this once... If you do as the link suggests you could actually end up stealing my code for your homework with no one being the wiser, but since that option is now on the table I am somehow doubting anyone will help you use the search thingy to find that post of mine.


    [edit]789502 for anyone who would even know what to do with that number.[/edit]
    Last edited by master5001; 10-24-2008 at 01:06 PM.

  5. #5
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    Hi all. Thanks for all the reply.
    What about this function char *substring(char *stra, char *strb);

    Function returns NUll when strb is not a substring of stra. On the other hand, when strb is a substring of stra, it returns a pointer pointing to the 1st occurrance of strb in stra.

  6. #6
    spurious conceit MK27's Avatar
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    Code:
    #include <stdio.h>
    #include <string.h>
    
    char *substring (char *string, char *sub) {
    	int stl=strlen(string), sbl=strlen(sub), i, n;
    	char chunk[sbl+1], *ptr;
    	for (i=0;i<stl;i++) {
    		if (sbl+i > stl) return NULL;
    		for (n=0;n<sbl;n++) chunk[n]=string[i+n];
    		chunk[n]=0;
    		if (strcmp(sub,chunk) == 0) {return (char*)string+i;}
    	}
    	return NULL;
    }
    
    int main() {
    	char string[64], sub[64], *ptr;
    	printf("Enter a string: ");
    	fgets(string,63,stdin);
    	printf("Enter a substring: ");
    	fgets(sub,63,stdin);
    	sub[strlen(sub)-1]=0;  // remove newline
    	ptr=substring(string,sub);
    	if (ptr != NULL) printf("%s\n",ptr);
    }
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

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