zip_file_extra_field_get
NAME
zip_file_extra_field_get
,
zip_file_extra_field_get_by_id
—
get extra field for file in zip
LIBRARY
libzip (-lzip)
SYNOPSIS
#include
<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)
HISTORY
zip_file_extra_field_get
() and
zip_file_extra_field_get_by_id
() were added in
libzip 0.11.
AUTHORS
Dieter Baron <dillo@nih.at> and Thomas Klausner <wiz@gatalith.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.