Win32 API CopyFile() fails to send multiple files

Question

While attempting to use the CopyFile() function I have encountered a strange error. It will write neither of the files to my destination.

Here is the code. The section when I send files has been commented. Keep in mind this code is a rough draft so ignore the function definitions.

/*


BrowserFind.c
Version 0.2
07/29/09

LogicKills

*/


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

char* getPath();
char* combineStrings(char* profile, char* path);
char** findProfile(char* path);
void copyagain();




int main()
{ 
    int fileIndex;
    char* fileLocation     = getPath();  
    char* whereAmI         = _getcwd(NULL,0);
    char **files           = findProfile(fileLocation);
    char* filesToExport[3] = {"\\formhistory.sqlite","\\cookies.sqlite", "\\downloads.sqlite"};
    char* profileName      = files[2];
    char* partPath         = strncat(fileLocation,"\\",3);
    char* pathWoutFile     = strncat(fileLocation,profileName,strlen(profileName) + 1);
    char* fullPathWithFile;
    char* fullSendPath;

    char* downloads = "\\downloads.sqlite";
    char* cookies   = "\\cookies.sqlite";
    char* history   = "\\formhistory.sqlite";







     char* from1 = strncat(fileLocation,filesToExport[0],100);
     char* send1 = strncat(whereAmI,filesToExport[0],100);


      char* from2 = strncat(fileLocation,filesToExport[1],100);
     char* send2 = strncat(whereAmI,filesToExport[1],100);



// ***** This is where I try to send the files ***** 

CopyFile(from1,send1,TRUE);

//Fails when I add two calls to CopyFile();
CopyFile(from2,send2,TRUE);

    return 0;
}

char* getPath()
{

      char* appPath;
      char* usrPath;
      char* fullPath;
      char* drive     = getenv("SYSTEMDRIVE");
      char* user      = getenv("USERNAME");


      OSVERSIONINFO info;
      info.dwOSVersionInfoSize = sizeof(info);
      GetVersionEx(&info);

      if (info.dwMajorVersion >= 6)
      {
        appPath = "\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles";
        usrPath = "\\Users\\";
      }

      else
      {
         appPath = "\\Application Data\\Mozilla\\Firefox\\Profiles";
         usrPath = "\\Documents and Settings\\";
      }

      strncat(drive,usrPath,strlen(usrPath) + 1);
      strncat(drive,user,strlen(user) + 1);
      strncat(drive,appPath,strlen(appPath) + 1);
      fullPath = drive;



      return (fullPath);
}

char** findProfile(char* path)
{

    DIR *dir = opendir (path);
    struct dirent *dp;          
    size_t filecount = 0;       
    size_t i = 0;
    char **files;

    if (dir == NULL) {

        return NULL;           
    }
    while ((dp = readdir (dir)) != NULL) {
        filecount++;
    }

    files = (char **) malloc (filecount * sizeof (*files));
    if (files == NULL) {
        return NULL;            
    }


    rewinddir (dir);
    while ((dp = readdir (dir)) != NULL) {
        files[i] = strdup (dp->d_name);
        if (files[i] == NULL) {

            while (i > 0) {
                free (files[--i]);
            }
            free (files);
            return NULL;
        }

        i++;
    }

    closedir (dir);
    return files;
}

Answer 1

in your code:

char* whereAmI         = _getcwd(NULL,0);

allocates exactly enough memory for the path

char* send2 = strncat(whereAmI,filesToExport[1],100);

strncat then tries to add to that path, using memory that isn't there.

Result: undefined behaviour.

Answer 2

I think at least part of your problem is that from1 and from2 point to the same string (as does send1 and send2).

These lines both return a printer to fileLocation, so from1 and from2 point to the same thing. Similar for send1 and send2.

 char* from1 = strncat(fileLocation,filesToExport[0],100);
 char* from2 = strncat(fileLocation,filesToExport[1],100);

Another problem is that you are overwriting buffers (and/or writing to buffers that you don't own).

getcwd() returns a pointer to memory that you are not allowed to modify, while _getcwd() returns a pointer to malloc'ed memory (so you can modify it), it's only as large as the string that's returned (as far as you know) so you can't concatenate to it.