Declaring char array results segmentation fault in C programming language - c

Question

I was just creating simple implementation where I read input.txt file which has one line of code containing two numbers separated by space (e.g. 4 4).
I was trying to separate them by delimiting with space first.
And I was trying to use the first value as a size of char array.
However it keeps causing segmentation fault but I have no idea.
int main(int argc, char **argv){
int number;
int i = 0;
char *token;
char buf[100];
int tempNum[2];
// Open file
FILE * fPointer;
fPointer = fopen("input.txt", "r");
// Read first line
fgets(buf, 1024, fPointer);
token = strtok(buf, " ");
number = atoi(token);
char charArray[number];
while(token != NULL){
tempNum[i] = atoi(token);
token = strtok(NULL, "\n");
printf("%d\n", tempNum[i]);
i++;
}
If I comment out "char charArray[number]" it does not cause segmentation fault. If I comment out only the while loop, it does not cause segmentation fault. But I cannot figure out why it is causing the segmentation in the first place. Please help.
Thank you in advance.

Answer 1

Something like this?
#include <stdlib.h>
#include <stdio.h>
#include <stdio.h>
#include <string.h>
#define BUF_SIZE 1024
#define MAX_INPUT 2
int main(int argc, char **argv) {
char *token = NULL;
char *next_token = NULL;
char buf[BUF_SIZE];
long tempNum[MAX_INPUT] = { 0 };
const char *delim = " ";
char * end = NULL;
// Init vars
memset(buf, 0, BUF_SIZE);
// Open file
FILE * fPointer = fopen("input.txt", "r");
if (fPointer == NULL) {
return 1;
}
// Read first line
if (fgets(buf, BUF_SIZE, fPointer) == NULL) {
fclose(fPointer);
return 2;
}
// Parse line
token = strtok_s(buf, delim, &next_token);
for (int i = 0;((i < MAX_INPUT) && (token != NULL)); i++){
tempNum[i] = strtol(token, &end, 10);
if (*end != NULL){
printf("error in %s\n", token);
} else {
printf("%d\n", tempNum[i]);
}
token = strtok_s(NULL, delim, &next_token);
}
fclose(fPointer);
return 0;
}