| .\" zip_file_extra_field_get.mdoc -- get extra field for file in zip |
| .\" Copyright (C) 2012-2017 Dieter Baron and Thomas Klausner |
| .\" |
| .\" This file is part of libzip, a library to manipulate ZIP files. |
| .\" The authors can be contacted at <libzip@nih.at> |
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| .Dd December 18, 2017 |
| .Dt ZIP_FILE_EXTRA_FIELD_GET 3 |
| .Os |
| .Sh NAME |
| .Nm zip_file_extra_field_get , |
| .Nm zip_file_extra_field_get_by_id |
| .Nd get extra field for file in zip |
| .Sh LIBRARY |
| libzip (-lzip) |
| .Sh SYNOPSIS |
| .In zip.h |
| .Ft const zip_uint8_t * |
| .Fn 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" |
| .Ft const zip_uint8_t * |
| .Fn 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" |
| .Sh DESCRIPTION |
| The |
| .Fn zip_file_extra_field_get |
| function returns the extra field with index |
| .Ar extra_field_index |
| for the file at position |
| .Ar index |
| in the zip archive. |
| This pointer should not be modified or |
| .Xr free 3 Ap d , |
| and becomes invalid when |
| .Ar archive |
| is closed. |
| If |
| .Ar idp |
| is not |
| .Dv NULL , |
| the integer to which it points will be set to the ID (two-byte |
| signature) of the selected extra field. |
| If |
| .Ar lenp |
| is not |
| .Dv NULL , |
| the integer to which it points will be set to the length of the |
| extra field. |
| Generally speaking, |
| .Ar lenp |
| and |
| .Ar idp |
| should be passed since only the extra field data is returned (i.e., |
| neither the ID nor the length, if the |
| .Ar idp |
| and |
| .Ar lenp |
| arguments are not provided). |
| .Pp |
| The following |
| .Ar flags |
| are supported: |
| .Bl -tag -width ZIP_FL_UNCHANGEDXX -offset indent |
| .It Dv ZIP_FL_CENTRAL |
| Return extra fields from the archive's central directory. |
| .It Dv ZIP_FL_LOCAL |
| Return extra fields from the local file headers. |
| .It Dv ZIP_FL_UNCHANGED |
| Return the original unchanged extra fields, ignoring any changes made. |
| .El |
| .Pp |
| The |
| .Fn zip_file_extra_field_get_by_id |
| function returns the extra field with ID (two-byte signature) |
| .Ar extra_field_id |
| and index |
| .Ar extra_field_index |
| (in other words, the |
| .Ar extra_field_index Ns No 'th |
| extra field with ID |
| .Ar extra_field_id ) |
| The other arguments are the same as for |
| .Fn zip_file_extra_field_get . |
| .Sh RETURN VALUES |
| Upon successful completion, a pointer to an extra field is returned, |
| or |
| .Dv NULL |
| if there is no extra field with that |
| .Ar extra_field_index |
| for the file with index |
| .Ar index . |
| In case of an error, |
| .Dv NULL |
| is returned and the error code in |
| .Ar archive |
| is set to indicate the error. |
| .Sh ERRORS |
| .Fn zip_file_extra_field_get |
| and |
| .Fn zip_file_extra_field_get_by_id |
| fail if: |
| .Bl -tag -width Er |
| .It Bq Er ZIP_ER_NOENT |
| .Ar index |
| is not a valid file index in |
| .Ar archive , |
| or |
| .Ar extra_field_index |
| is not a valid extra file index (for ID |
| .Ar extra_field_id ) . |
| .El |
| .Sh SEE ALSO |
| .Xr libzip 3 , |
| .Xr zip_file_extra_field_delete 3 , |
| .Xr zip_file_extra_field_set 3 , |
| .Xr zip_file_extra_fields_count 3 |
| .Sh HISTORY |
| .Fn zip_file_extra_field_get |
| and |
| .Fn zip_file_extra_field_get_by_id |
| were added in libzip 0.11. |
| .Sh AUTHORS |
| .An -nosplit |
| .An Dieter Baron Aq Mt dillo@nih.at |
| and |
| .An Thomas Klausner Aq Mt tk@giga.or.at |
| .Sh 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 |
| .Fn zip_file_extra_field_get |
| since they are used by |
| .Xr libzip 3 |
| internally. |
