c - Why does this SEGFAULT? (small amount of code) -

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#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>  #include "mystuff.h"  typedef struct node {         int size;         int status;         struct node *next;         struct node *previous; } node;   node *endnode; node *rootnode;  void *my_foo(int size) {         node *thenode;         void *ptr;          if (rootnode->next == null)         {                 thenode->status = 1;                 ...

it segfaults @ "rootnode-> == null" if change "rootnode == null" segfaults when hits "thenode->status = 1" , declaring thenode , rootnode null not help.

...and declaring thenode , rootnode null not help.

dereferencing null (usually) will result in segfault. you've got set them more useful (like allocated structure) before go off modifying them!


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