Question

I need to build up a path to a file. I have the following class method:

void Directory::scanDirectory(char *directory) {
    DIR *dirp;
    struct dirent *entry;
    char path[1];

    if(dirp = opendir(directory)) {
        while(entry = readdir(dirp)) {
            if (entry->d_name[0] != '.') {
                strcpy(path, directory);
                strcat(path, "/");
                strcat(path, entry->d_name);
                if (entry->d_type == 8) {
                    // Files
                } else if (entry->d_type == 4) {
                    //scanDirectory(path);
                }
                printf("Name: %s, Type: %d\n", entry->d_name, entry->d_type);
            }
        }
        closedir(dirp);
    }
}

I need to build up the path to files by concatenating the directory and entry->d_name. When I try running this code it segfaults. From what I can tell it’s segfaulting at the point where I build the path. Is there a better way of doing this?

Answer 1

The buffer path needs to have enough space to hold the whole path. Right now it only has space for a single character. Try making it bigger. strcat doesn’t allocate space itself. You have to manually manage that memory.

As for a better way, you may want to look into using a string. You won’t need to worry about memory, and you can concatenate with the + operator.