Thread: Array Elements Overwritten

I suppose the question is, how sure are you that paths[i] is correct when the function starts? Maybe add an extra for-loop at the front to print all the paths before the main for loop that reads things. The only thing that I don't know what it is is this pCurPath thing. What is that, and what does it point to, and why do you free it every time through the loop?

I actually have one at the beginning of the function, but I removed it before posting for brevity
So yes, the paths array definitely looks okay at the beginning of the function.

Well, freeing pCurPath still looks a little suspicious. (What if it points to the paths?) I don't see anything else that can tromp on your array.

sorry...forgot to take that line out. that's a leftover char* from when i tried, on each iteration, to copy the contents of path[i] into a temporary string pointer. i thought that would prevent any code from touching the actual array besides strcpy, but it didn't fix my problem.

Then you're not having any problems then.

Originally Posted by my machine

Search path before loop: DayDate
Found a file.
file:.
.
.
.
Search path before loop: Documents
Found a file.
.
.
.
Search path before loop: Library
Found a file.
.
.
.

so you ran that fine on your machine? how could that be? i ran this code on both a linux vm, and then on os x, and got the same result for both. assuming the array argument looks fine coming into the function, is there anything that could mess with it?

The code looks like so:

Code:

#include <stdio.h>
#include <unistd.h>
#include <dirent.h>

int processIt(const char* command,  char* paths[])
{
  printf("processIt\n");

  int status;
  int i;

  DIR *dir;
  struct dirent *entry;
  int x;

  for (i = 0; paths[i] != NULL; i++) {
    printf("Search path before loop: %s\n", paths[i]);

    dir = opendir(paths[i]);
    if (dir == NULL) {
      printf("Error");
     return -1;
    }

    while ((entry = readdir(dir)) != NULL) {
      printf("Found a file.\n");
      printf("file:%s\n", entry->d_name);
    }

    closedir(dir);

  }


  return 0;
} /* processIt! */

int main(int argc, char *argv[])
{
    char *paths[] = {"DayDate", "Documents", "Library", 0};
    processIt("ls", paths);
 return 0;
}

Obviously, those are just three directories I happened to choose out of my home directory. I took out some of the variables that weren't being used, too.

I can do the same thing and everything works fine. This is crazy! In both cases, the array argument looks fine when I enter the function. But something else must be going on...can I send you the rest of my code (it's only like 3 files)?

Thanks for your help!

Originally Posted by Zoetermeer

I can do the same thing and everything works fine. This is crazy! In both cases, the array argument looks fine when I enter the function. But something else must be going on...can I send you the rest of my code (it's only like 3 files)?

Thanks for your help!

You should be able to attach it to a message here, sure.

ok, here are the three files (i tried to attach the makefile but i think the site won't allow it). let me know if this works.

around line 150, i have both the "actual" code (that passes in the array, where i was having problems), as well as some commented code that passes in the test array as you did.

also - i managed to look at this in the debugger, and the array contents seem to get mangled right after the first call to opendir.

i can't thank you enough!

so you added that loop directly after the call to tokenize? i tried running it by adding those two lines and still got the garbled data in the array on the second iteration.

Inside util.c, this looks wrong:

Code:

  copyofstring= (char *)malloc(strlen(string));
  strcpy(copyofstring, string);

Should allow for one more byte for trailing nul.