zip_get_archive_comment man page
zip_get_archive_comment — get zip archive comment
const char *
zip_get_archive_comment(zip_t *archive, int *lenp, zip_flags_t flags);
The zip_get_archive_comment() function returns the comment for the entire zip archive. The name is in UTF-8 encoding unless ZIP_FL_ENC_RAW was specified (see below). This pointer should not be modified or free(3)'d, and becomes invalid when archive is closed. If lenp is not NULL, the integer to which it points will be set to the length of the comment. If flags is set to ZIP_FL_UNCHANGED, the original unchanged comment is returned.
Additionally, the following flags are supported:
Return the unmodified archive comment as it is in the ZIP archive.
(Default.) Guess the encoding of the archive comment in the ZIP archive and convert it to UTF-8, if necessary.
Follow the ZIP specification for file names and extend it to the archive comment, thus also expecting it in CP-437 encoding. Convert it to UTF-8.
Note: ASCII is a subset of both CP-437 and UTF-8.
Upon successful completion, a pointer to the comment is returned, or NULL if there is no comment.
Dieter Baron <email@example.com> and Thomas Klausner <firstname.lastname@example.org>
libzip(3), zip_file_get_comment(3), zip_file_set_comment(3), zip_set_archive_comment(3).