Thread: C Segmentation Fault Help

Hi, I'm having some problems getting the following code to run without reaching a segmentation fault error. It compiles and gives the proper output, but does not close properly and I can't for the life of me figure out why. You can see the code at this link (C code - 50 lines - codepad) or below:

Code:

#include <stdio.h>
#include <ctype.h>

/*
Function: count_match_char_in_array
Purpose:
        Take input character array and count number of characters that match
        an input character value without regard to case and return the count found

InputArray - Array to scan for matching characters
MatchChar - Character to match against
ReturnCount - Count of how many characters passed in MatchChar are found in InputArray

Returns:
        Number of characters in InputArray

*/
int count_match_char_in_array(const char *InputArray, char MatchChar, int *ReturnCount)
{
        int i;
	*ReturnCount = 0;

        for(i=0;InputArray[i] != '\0';i++)
        {
                /* If we match the input char, bump the character count */
                if(tolower(InputArray[i]) == MatchChar)
                {
                        (*ReturnCount)++;
                }

        }
        return(i);
}

/*
Purpose:
        Test CountMatchCharInArray function
        Will input test string and print out the matching count and the number
                of characters in the input test string
*/
main()
{
        int *Count;
        int CharCount;

        CharCount = count_match_char_in_array("Do you know the way to San Jose?", 'a',
                        Count);

        printf("Found %d occurrences in a total length of: %d\n", *Count, CharCount);
}

You had a null pointer assignment. Correct version:

Code:

#include <stdio.h>
#include <ctype.h>

/*
Function: count_match_char_in_array
Purpose:
        Take input character array and count number of characters that match
        an input character value without regard to case and return the count found

InputArray - Array to scan for matching characters
MatchChar - Character to match against
ReturnCount - Count of how many characters passed in MatchChar are found in InputArray

Returns:
        Number of characters in InputArray

*/
int count_match_char_in_array(const char *InputArray, char MatchChar, int *ReturnCount)
{
        int i;
	//*ReturnCount = 0;

        for(i=0;InputArray[i] != '\0';i++)
        {
                /* If we match the input char, bump the character count */
                if(tolower(InputArray[i]) == MatchChar)
                {
                        (*ReturnCount)++;
                }

        }
        return(i);
}

/*
Purpose:
        Test CountMatchCharInArray function
        Will input test string and print out the matching count and the number
                of characters in the input test string
*/
int main()
{
        int Count=0;
        int CharCount=0;
        printf("\n\n");
        CharCount = count_match_char_in_array("Do you know the way to San Jose?", 'a',
                        &Count);

        printf("Found %d occurrences in a total length of: %d\n", Count, CharCount);

  (void) getchar();
  return 0;
}

Thank you very much!

That assessment was from my compiler, just before the program crashed. I trust it.

I never said that *ReturnCount was the problem with the program. If you notice, I left it in there. The assigning of *ReturnCount to zero was REM'd out because it was simply redundant.

When you have a long line of code or text, inside code tags, like this one:

printf("Found %d occurrences in a total length of: %d\n", *Count, CharCount); // [Count] Use of uninitialised value of size 8. CharCount is initialized by count_match_char_in_array() call

Please break it up into two or three lines. Otherwise it "breaks" the forums table width settings.

Thanks, and

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