Int Array Being Changed In Function

[klxp9]

These two arrays

/* One Hour Set */
   int one_set_begin[] = {4, 7, 10, 13, 16, 19, 20, 22, 23, 23};
/* One Hour Set */
   int one_set_end[] =   {6, 9, 12, 15, 18, 20, 21, 23, 23, 24};

...are being passed into this function

int create_statement(char hd_begin[2], char *statement, const int *begin, const int *end)

Here's some of the code within that function

char class_no[5];
   int total_in_set = 10;
   int i, j, k;

   for(j = 0; j <= total_in_set-1; j++){
      strcat(statement, "SELECT * FROM (SELECT * FROM dj_music WHERE hd='");
      strcat(statement, hd_begin);

      if(strcmp(hd_begin, "A") == 0)
         strcpy(hd_begin, "B");
      else
         strcpy(hd_begin, "A");

      strcat(statement, "' AND (");

      for(k = begin[j]; k < end[j]+1; k++) {
         strcat(statement, "(classnumber=");
         sprintf(class_no, "%d", k);
         strcat(statement, class_no);
         strcat(statement, ")");

         if(k < end[j])
            strcat(statement, " OR ");
      }
   <snip>

When it gets down to here

for(k = begin[j]; k < end[j]+1; k++) {

...begin[0] (for example) is 134535230, but before that line it read properly as 4.

Why is my int array being changed? Thanks.

[kbw]

How big is statement? Is it being overritten with the strcat/strcpy functions?

[Disch]

Looks to me like it might be memory corruption. You're probably going out of bounds on one of your string buffers and text is "spilling" into your begin/end buffers. Probably 'statement' simply isn't large enough to hold all of the text you're copying to it.

You might want to consider switching from C style strings over to C++'s string and stringstream . This will make memory corruption caused by buffer overflow virtually impossible:

(also seems weird that you're using hd_begin as a string when really it's just a single char):

int create_statement(char hd_begin, stringstream& statement, ...)
{
  statement << "SELECT * FROM (SELECT * FROM dj_music WHERE hd='";
  statement << hd_begin;

  if(hd_begin == 'A')  hd_begin = 'B';
  else                 hd_begin = 'A';

  statement << "'AND (";

  for(k = begin[j]; k <= end[j]; ++k)
  {
    statement << "(classnumber=" << hd_begin << k << ')';

    if(k < end[j])
      statement << " OR ";
  }
  // ... 

stringstream statement(stringstream::in | stringstream::out);
create_statement(hd_begin,staement,one_set_begin,one_set_end);

// to get a c-style string from that, get a std::string first
string str = statement.str();

// then get a c-string
const char* buffer = str.c_str();

// 'buffer' remains valid until 'str' loses scope. 

[klxp9]

OK, thanks for the help guys. Got it to work correctly.