xenial (3) zip_file_extra_field_get.3.gz

NAME

       zip_file_extra_field_get, zip_file_extra_field_get_by_id - get extra field for file in zip

LIBRARY

       libzip (-lzip)

SYNOPSIS

       zip.h  const  zip_uint8_t  *  zip_file_extra_field_get  zip_t  *archive  zip_uint64_t  index zip_uint16_t
       extra_field_index  zip_uint16_t  *idp  zip_uint16_t  *lenp  zip_flags_t   flags   const   zip_uint8_t   *
       zip_file_extra_field_get_by_id zip_t *archive zip_uint64_t index zip_uint16_t extra_field_id zip_uint16_t
       extra_field_index zip_uint16_t *lenp zip_flags_t flags

DESCRIPTION

       The zip_file_extra_field_get function returns the extra field with index extra_field_index for  the  file
       at  position  index  in  the  zip archive.  This pointer should not be modified or free(3)'d, and becomes
       invalid when archive is closed.  If idp is not NULL, the integer to which it points will be set to the ID
       (two-byte  signature)  of  the selected extra field.  If lenp is not NULL, the integer to which it points
       will be set to the length of the extra field.  Generally speaking, lenp and idp should  be  passed  since
       only the extra field data is returned (i.e., neither the ID nor the length, if the idp and lenp arguments
       are not provided).

       The following flags are supported:

       ZIP_FL_CENTRAL
              Return extra fields from the archive's central directory.

       ZIP_FL_LOCAL
              Return extra fields from the local file headers.

       ZIP_FL_UNCHANGED
              Return the original unchanged extra fields, ignoring any changes made.

       The zip_file_extra_field_get_by_id  function  returns  the  extra  field  with  ID  (two-byte  signature)
       extra_field_id  and index extra_field_index (in other words, the extra_field_index'th extra field with ID
       extra_field_id) The other arguments are the same as for zip_file_extra_field_get.

RETURN VALUES

       Upon successful completion, a pointer to an extra field is returned, or NULL if there is no  extra  field
       with that extra_field_index for the file with index index.  In case of an error, NULL is returned and the
       error code in archive is set to indicate the error.

ERRORS

       zip_file_extra_field_get and zip_file_extra_field_get_by_id fail if:

       [ZIP_ER_NOENT]   index is not a valid file index in archive, or extra_field_index is not  a  valid  extra
                        file index (for ID extra_field_id).

SEE ALSO

       libzip(3), zip_file_extra_field_delete(3), zip_file_extra_field_set(3), zip_file_extra_fields_count(3)

AUTHORS

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

CAVEATS

       Please note that the extra field IDs 0x0001 (ZIP64 extension), 0x6375 (Infozip UTF-8 comment), and 0x7075
       (Infozip UTF-8 file name) can not be read using zip_file_extra_field_get since they are used by libzip(3)
       internally.