seg fault Need help

Code:

#include <stdio.h>

int main(void)
{
  char* ch;
  int max = 1000;
  int i = 0;
  /* read character by character from stdin */


    while (fgets(ch, max, stdin) != NULL){

      printf("%s ",ch);
      i++;
    }
  return 0;
}

THIS is my program and when i do
program < README

Code:

XXXXXXX XXXXXX
XXXXXX XXXXX
CS101 
Assignment 1

List.java
This program is to manipulate a LIST ADT giving it multiple functions 
either ways to adjust a list by adding nodes or deleting them. It will
change pointers like make current go to the top of the list or bottom or
even move it to go a space up or down. List also contain boolean functions
like it would check to see if the list is empty or where current is. The
main purpose of List.java is to create a list and make it a certain way 
for user to make.

ListTest.java 
This was just multiple function calls to make it work or see if 
List.java actually works many test trials over each function.

Shuffle.java
This program is to manipulate a list to do Permutaion alignment like 
giving a list of permutation, then create a List going for n to n-1. 
The Permutation list will then adjust teh new list to arrange the certain
numbers to the order of the permutation list. This is the main function 
that calls on List.java.

I get a seg fault at the very very end wit the line
that calls on List.java why is that happening

It gives segmentation fault because you are not allocating the memory for the string.
Try this code.

Code:

#include <stdio.h>
#include<malloc.h>

int main(void)
{
  char* ch;
  int max = 1000;
  int i = 0;
  /* read character by character from stdin */


  ch=(char *)malloc(max);
    while (fgets(ch, max, stdin) != NULL){

      printf("%s ",ch);
      i++;
    }
    free(ch);
  return 0;
}

"ch" doesn't point to anything meaningful, it's initialised with whatever.

Perhaps you mean:

Code:

char buffer[1000];

while(fgets(buffer, sizeof buffer, stdin) != NULL)
{
   ...

?

Normally, If the pointer points something no need to allocate the memory. It will take the memory from which it is points.
Ex:

Code:

char arr[max];
char *ch;
ch=arr; // It points the memory from arr.

But If you are using pointer alone, that is it needs to point the new memory not the some other memory. So in this case you need to allocate the memory.

Code:

char *ch;
ch = (char *)malloc(max);// It points new memory that is return by malloc.

Segmentation fault error will come when the pointer tries to point illegal or non-allocated or not-allowed or read-only location.