Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17


Why is malloc overwriting the contents of my variable?

Posted on 2007-03-26
Medium Priority
Last Modified: 2010-05-18
Can anyone see why my *jobID is being overwritten???

              char *jobID =      "123456789";
                         DWORD size = GetCurrentDirectory(0,NULL); /*  size == size needed for array - 1 */
            char *szPwd = (char *)malloc((sizeof(char)size)+1);
            if(!szPwd) {
                  puts("Could not allocate buffer for pwd");
            if(!GetCurrentDirectory(size+1,szPwd)) {
                  printf("Could not get size: Error:%d\n",GetLastError());
            char *szDir = (char *)malloc(sizeof(char)size+10);  /* PROBLEM HERE */
            /* The statement above is what overwrites the contents of *jobID with what looks like part of a path */
            if(!szDir) {
                  puts("Could not allocate Memory for directory name");
            printf("JobID is %s\n",jobID);
Question by:TristinColby
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
LVL 53

Expert Comment

ID: 18796271
     char *szDir = (char *)malloc(sizeof(char)size+10);  /* PROBLEM HERE */

make that :

      char *szDir = (char *)malloc(size+10);  /* PROBLEM HERE */
LVL 53

Accepted Solution

Infinity08 earned 2000 total points
ID: 18796279
Same here :

            char *szPwd = (char *)malloc((sizeof(char)size)+1);

becomes :

            char *szPwd = (char *)malloc(size+1);

and here :


becomes :


Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Preface I don't like visual development tools that are supposed to write a program for me. Even if it is Xcode and I can use Interface Builder. Yes, it is a perfect tool and has helped me a lot, mainly, in the beginning, when my programs were small…
This tutorial is posted by Aaron Wojnowski, administrator at  To view more iPhone tutorials, visit This is a very simple tutorial on finding the user's current location easily. In this tutorial, you will learn ho…
The goal of this video is to provide viewers with basic examples to understand and use conditional statements in the C programming language.
The goal of this video is to provide viewers with basic examples to understand and use switch statements in the C programming language.

704 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question