Re: grokking libgsf

[Jon K Hellan <hellan acm org>]

Allin Cottrell wrote:
> I'm trying some tests with the hope of switching to libgsf in
> place of low-level fiddling with pkzip structures in reading and
> writing zipfiles.  So far I'm only partially successful and I'd
> much appreciate any guidance.
>
> I have the following C source (with correct headers included, and
> followed by a trivial main() function).  The idea is to print the
> structure of a zipfile and then "unzip" it to a specified
> location.
>
> The printing part, "print_kids", is working fine, but the
> "unzipping" part is giving me an empty directory "foo".  I have
> removed error-checking from the following for brevity, but no
> errors were triggered when running the full version of the code.

There is example code in the 'tests' subdirectory. You may already have discovered this.
It looks like test-cp-zip.c should be a good starting point.

Regards

Jon Kåre

> static void print_kids (GsfInfile *infile, int level)
> {
>     int nkids = gsf_infile_num_children(infile);
>     const char *cname;
>     GsfInput *child;
>     gsf_off_t sz;
>     int i, j;
>
>     for (i=0; i<nkids; i++) {
>         child = gsf_infile_child_by_index(infile, i);
>         cname = gsf_input_name(child);
>         sz = gsf_input_size(child);
>         for (j=0; j<level; j++) {
>             putchar(' ');
>         }
>         printf("child %d: '%s' (%d bytes)\n", i, cname, (int) sz);
>         print_kids(GSF_INFILE(child), ++level);
>         g_object_unref(child);
>     }
> }
>
> static int gsf_test_zipread (const char *fname)
> {
>     GsfInput *src, *uncomp;
>     GsfInfile *zipfile;
>     GsfOutfile *outfile;
>
>     gsf_init();
>
>     src = gsf_input_stdio_new(fname, NULL);
>     zipfile = gsf_infile_zip_new(src, NULL);
>     g_object_unref(src);
>
>     print_kids(zipfile, 0);
>
>     uncomp = gsf_input_uncompress(GSF_INPUT(zipfile));
>     g_object_unref(zipfile);
>
>     outfile = gsf_outfile_stdio_new("foo", &err);
>
>     gsf_input_seek(uncomp, 0, G_SEEK_SET);
>     gsf_output_seek(GSF_OUTPUT(outfile), 0, G_SEEK_SET);
>
>     if (!gsf_input_copy(uncomp, GSF_OUTPUT(outfile))) {
>         fprintf(stderr, "gsf_input_copy failed\n");
>     }
>
>     gsf_output_close(GSF_OUTPUT(outfile));
>     gsf_shutdown();
>
>     return 0;
> }
>
> Please, what am I doing wrong in gsf_test_zipread?