adding segfault code

lab1/starter/segfault/Makefile

@@ -0,0 +1,19 @@
+CC=gcc
+CFLAGS=-Wall -g
+LD=gcc
+LDFLAGS=-g
+
+
+OBJS=main_segv.o
+
+all: main_segv.out
+
+main_segv.out: $(OBJS) 
+	$(LD) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) 
+
+.c.o:
+	$(CC) $(CFLAGS) -c $<
+
+.PHONY: clean
+clean:
+	rm -f *.o *.out 

lab1/starter/segfault/README.md

@@ -0,0 +1 @@
+The sample code demonstrates a segmentation fault. 

lab1/starter/segfault/main_segv.c

@@ -0,0 +1,43 @@
+/**
+ * @brief: To demonstrate segmentation fault 
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct buf {
+    size_t size;  /* buffer size */
+    char *data ;  /* data */
+};
+
+/* To model a point on 2D terminal screen */
+struct point
+{
+    int x;
+    int y;
+};
+
+
+int main(void)
+{
+    struct buf *p, *q;
+    struct point pt={1,2};
+
+    p = (struct buf *)malloc(sizeof(struct buf));
+    q = p;
+
+    p->data = (char *)&pt ;
+    p->size = sizeof(struct point); 
+
+    printf("p->x = %d, p->y =%d\n", ((struct point*)(p->data))->x, ((struct point *)(p->data))->y);
+
+    /* remove pointe p */
+    p->data = NULL;
+    p->size = 0;
+    free(p);
+
+    printf("q->x = %d, q->y =%d\n", ((struct point*)(q->data))->x, ((struct point *)(q->data))->y);
+
+
+    return(0);
+}