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
<
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.