Function keeps crashing without error message - c

Question

Hello I am taking an intro to C-programming class so I am using very basic codes. Here I am simply trying to get a matrix of the commas out of the main string. However when I try running the program it keeps crashing on me and I don't know what is my problem. I was able to use the fgets function correctly so I think that is working fine still.
CD Data.txt File
Eagles, Hotel California, 1976, Rock, 4
The Fratellis, Costello Music, 2006, Garage Rock, 5
Awolnation, Megalithic Symphony, 2011, Indie Rock, 5
Lindsey Stirling, Lindsey Stirling, 2012, Classical Crossover, 5
Arctic Monkeys, AM, 2013, Indie Rock, 4
Program
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define row 1000
#define column 1000
void getCommas(char str[], int commas[])
{
int flag, count, index;
count = 0;
index = 0;
flag = 1;
while(flag = 1)
{
if(str[count] = ',')
{
commas[index] = count;
index = index + 1;
}
count = count + 1;
if(str[count] = '\0')
{
flag = 0;
}
}
}
int main()
{
int i;
char CdInfo[row][column];
int Index[row][column];
FILE *fp;
fp = fopen("CD Data.txt","r");
for(i=0; i<5; i++)
{
fgets(CdInfo[i], sizeof CdInfo, fp);
//printf("%s\n",CdInfo[i]);
}
for (i=0; i<5; i++)
{
getCommas(CdInfo[i], Index[i]);
}
fclose(fp);
return 0;
}

Answer 1

These two variables are too big to be on the stack:
int main()
{
int i;
char CdInfo[row][column]; //<<
int Index[row][column]; //<<
declare them as static or as global variables.
And:
while(flag = 1)
should be
while(flag == 1)
and all
if (str[count] = ...
should be
if(str[count] == ...

Answer 2

You should also think about replacing
while(flag = 1) {
with :
while(flag == 1)

Answer 3

// note:
// the code is not making any use of more than one line of the
// input file at any one time, so
// only the current row actually needs to be defined
// note:
// this code makes no check for max length of each row (1000 char)
// that could/will be a problem when the input line is longer than 1000 character
// to avoid the error of writing an assignment rather than a literal,
// place the literal on the left side,
// then the compiler will notify you of the error
// rather than you having to spend time debugging the code
// trying to find the error
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define row 1000
#define column 1000
//void getCommas(char str[], int commas[])
void getCommas( char * pStr, int * pCommas )
{
//int flag, count, index;
//count = 0;
//index = 0;
//flag = 1;
int flag = 1;
int count = 0;
int index = 0;
//while(flag = 1)
// following while loop could eliminate
// the 'flag' variable and related code by using
// and would be safer because never looking at string termination
// character but once.
// while( '\0' != pStr[count] )
while( 1 == flag )
{
//if(str[count] = ',')
if( ',' == pStr[count] )
{
pCommas[index] = count;
index = index + 1;
}
count = count + 1;
//if(str[count] = '\0')
if( '\0' == pStr[count] )
{ // then found end of string
flag = 0;
}
}
}
char CdInfo[row][column];
int Index[row][column];
int main()
{
int i = 0;
int rowCount = 0;
//char CdInfo[row][column]; // this is a huge item on the stack,
//int Index[row][column]; // this is a huge item on the stack,
//FILE *fp;
FILE *fp = NULL;
fp = fopen("CD Data.txt","r");
// always check the result of calls to io functions
if ( NULL == fp )
{ // then fopen failed
perror( "fopen" );
exit(1);
}
// implied else
// there is no reasonable reason (in the real world)
// to expect the input to be only 5 lines
//for(i=0; i<5; i++)
//{
// fgets(CdInfo[i], sizeof CdInfo, fp);
// //printf("%s\n",CdInfo[i]);
//}
for( i=0; i<row; i++ )
{
// following line checks results of call to I/O function
if( 0 == fgets( CdInfo[i], row, fp ) ) { break; }
// above line exits loop on end of file or I/O error
rowCount++;
}
//for (i=0; i<5; i++)
for( i = 0; i < rowCount; i++ )
{
getCommas(CdInfo[i], Index[i]);
}
fclose(fp);
return 0;
}