If option and value are both NULL these functions will do nothing and ARCHIVE_OK will be returned. If option is NULL but value is not, these functions will do nothing and ARCHIVE_FAILED will be returned.
If module is not NULL option and value will be provided to the filter or reader named module The return value will be either ARCHIVE_OK if the option was successfully handled or ARCHIVE_WARN if the option was unrecognized by the module or could otherwise not be handled. If there is no such module, ARCHIVE_FAILED will be returned.
If module is NULL option and value will be provided to every registered module. If any module returns ARCHIVE_FATAL this value will be returned immediately. Otherwise, ARCHIVE_OK will be returned if any module accepts the option, and ARCHIVE_FAILED in all other cases.
Individual options have one of the following forms:
Setting this boolean option will force the writer to use Zip64 extensions even for small files that would not otherwise require them. This is primarily useful for testing.
Disabling this option with !zip64 will force the Zip writer to avoid Zip64 extensions: It will reject files with size greater than 4 GiB, it will reject any new entries once the total archive size reaches 4 GiB, and it will not use Zip64 extensions for files with unknown size. In particular, this can improve compatibility when generating archives where the entry sizes are not known in advance.
a = archive_write_new(); archive_write_add_filter_gzip(a); archive_write_set_format_iso9660(a); archive_write_set_options(a, "boot=kernel.img,compression=9"); archive_write_open_filename(a, filename, blocksize);