ZIP_FILE_EXTRA_FIELDS_COUNT(3) | Library Functions Manual | ZIP_FILE_EXTRA_FIELDS_COUNT(3)

# 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`(zip_t *archive, zip_uint64_t index, zip_flags_t flags);

zip_int16_t
`zip_file_extra_fields_count_by_id`(zip_t *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.

# SEE ALSO

libzip(3), zip_file_extra_field_delete(3), zip_file_extra_field_get(3), zip_file_extra_field_set(3)

# HISTORY

`zip_file_extra_fields_count`() and `zip_file_extra_fields_count_by_id`() were added in libzip 0.11.

# AUTHORS

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

December 18, 2017 | NiH