zip_file_extra_field_get
,
zip_file_extra_field_get_by_id
—
get extra field for file in zip
libzip (-lzip)
#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);
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
().
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.
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).
libzip(3),
zip_file_extra_field_delete(3),
zip_file_extra_field_set(3),
zip_file_extra_fields_count(3)
zip_file_extra_field_get
() and
zip_file_extra_field_get_by_id
() were added
in libzip 0.11.
Dieter Baron
<
dillo@nih.at>
and
Thomas Klausner
<
tk@giga.or.at>
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.