How do I save a binary file from libzip

Question

My goal is to write file to disk

If I use gio to create the file

GError *error;
char path[strlen(dirpath)]; 
sprintf(path, "%s", dirpath); // Create path to the file by copying from another variable
zip_file_t *contentfile = zip_fopen_index(book, index, ZIP_RDONLY);
zip_stat_index(book, index, ZIP_CHECKCONS, &fileinfo);
GFile *gfile = g_file_new_for_path(strcat(path, fileinfo.name));
GFileOutputStream *file = g_file_create(gfile, G_FILE_CREATE_NONE, g_cancellable_new(), &error);
if (error)
    printf("Error :%i\n", error->code);
else
    zip_fread(contentfile, file, fileinfo.size);
g_error_free(error);

I cant put anything in the file. Its just a file created with 0 bytes. I am extracting all files on the archive with a loo. Hence index in zip_file_t *contentfile = zip_fopen_index(book, index, ZIP_RDONLY);. I am getting a segfault : GError set over the top of a previous GError or uninitialized memory.

If I use FILE

char path[strlen(dirpath)]; 
sprintf(path, "%s", dirpath); // Create path to the file by copying from another variable
zip_file_t *contentfile = zip_fopen_index(book, index, ZIP_RDONLY);
zip_stat_index(book, index, ZIP_CHECKCONS, &fileinfo);
FILE *file = fopen(strcat(path, fileinfo.name), "wb");
zip_fread(contentfile, file, fileinfo.size);

This gives a segmentation fault with : double free or corruption (out)

How do I properly write zip_read( contents to a file on disk?

Answer 1

@MikeCAT was right I first needed to fix my char path size. Using the same idea I changed my void *buffer to char buffer[size] and not a pointer. It does save files from some zips some are still giving segmentation error. I will investigate why [probably insufficient memory somewhere] but at least it does work for now. I will update later

Had to set buffer with malloc to avoid the error, now it works

static void extract_book(zip_t *book, char *bookname)
{
    int size = strlen(pubdir) + strlen(bookname) + 1;
    char pubpath[size];
    strncat(strncat(strcpy(pubpath, pubdir), bookname, strlen(bookname)), "/", 2);
    GFile *dir = g_file_new_for_path(pubpath);
    g_file_make_directory_with_parents(dir, NULL, NULL);
    for (int index = 0; index < zip_get_num_files(book); index++)
    {
        zip_file_t *contentfile = zip_fopen_index(book, index, 0);
        zip_stat_t fileinfo;
        int status = zip_stat_index(book, index, ZIP_FL_ENC_GUESS, &fileinfo);
        if (status == 0)
        {
            char *buffer = malloc(fileinfo.size);
            char filepath[size + strlen(fileinfo.name)];
            strcat(strcpy(filepath, pubpath), fileinfo.name);
            zip_fread(contentfile, buffer, fileinfo.size);
            zip_fclose(contentfile);
            FILE *file = fopen(filepath, "wb");
            fwrite(buffer, fileinfo.size, 1, file);
            fclose(file);
        }
        else
        {
            printf("%s at %i\n", puberror, zip_get_error(book)->zip_err);
        }
    }
}