ZIP_FILE_EXTRA_FIELDS_COUNT

Section: Library Functions Manual (3)
Updated: February 20, 2013
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NAME

zip_file_extra_fields_count, zip_file_extra_fields_count_by_id - count extra fields for file in zip

LIBRARY

libzip (-lzip)

SYNOPSIS

#include <zip.h>

zip_int16_t
zip_file_extra_fields_count(struct zip *archive, zip_uint64_t index, zip_flags_t flags);

zip_int16_t
zip_file_extra_fields_count_by_id(struct zip *archive, zip_uint64_t index, zip_uint16_t extra_field_id, zip_flags_t flags);

DESCRIPTION

The zip_file_extra_fields_count() function counts the extra fields for the file at position index in the zip archive.

The following flags are supported:

ZIP_FL_CENTRAL: Count extra fields from the archive's central directory.
ZIP_FL_LOCAL: Count extra fields from the local file headers.
ZIP_FL_UNCHANGED: Count the original unchanged extra fields, ignoring any changes made.

The zip_file_extra_fields_count_by_id() function counts the extra fields with ID (two-byte signature) extra_field_id. The other arguments are the same as for zip_file_extra_fields_count().

Extra fields that are the same in the central directory and the local file header are merged into one. Therefore, the counts with ZIP_FL_CENTRAL and ZIP_FL_LOCAL do not need to add up to the same value as when given ZIP_FL_CENTRAL|ZIP_FL_LOCAL at the same time.

RETURN VALUES

Upon successful completion, the requested number of extra fields is returned. Otherwise, -1 is returned and the error code in archive is set to indicate the error.

ERRORS

zip_file_extra_fields_count() and zip_file_extra_fields_count_by_id() fail if:

[ZIP_ER_NOENT]: index is not a valid file index in archive.

AUTHORS

Dieter Baron <dillo@nih.at> and Thomas Klausner <tk@giga.or.at>