.\" zip_file_get_comment.mdoc -- get comment for file in zip
.\" Copyright (C) 2006-2021 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 September 22, 2020
.Dt ZIP_FILE_GET_COMMENT 3
.Os
.Sh NAME
.Nm zip_file_get_comment
.Nd get comment for file in zip
.Sh LIBRARY
libzip (-lzip)
.Sh SYNOPSIS
.In zip.h
.Ft const char *
.Fn zip_file_get_comment "zip_t *archive" "zip_uint64_t index" "zip_uint32_t *lenp" "zip_flags_t flags"
.Sh DESCRIPTION
The
.Fn zip_file_get_comment
function returns the comment for the file at position
.Ar index
in the zip archive.
The name is in UTF-8 encoding unless
.Dv ZIP_FL_ENC_RAW
was specified (see below).
This pointer should not be modified or
.Xr free 3 Ap d ,
and becomes invalid when
.Ar archive
is closed.
If
.Ar lenp
is not
.Dv NULL ,
the integer to which it points will be set to the length of the
comment.
If
.Ar flags
is set to
.Dv ZIP_FL_UNCHANGED ,
the original unchanged comment is returned.
.Pp
Additionally, the following
.Ar flags
are supported:
.Bl -tag -width ZIP_FL_ENC_STRICTXX -offset indent
.It Dv ZIP_FL_ENC_RAW
Return the unmodified comment as it is in the ZIP archive.
.It Dv ZIP_FL_ENC_GUESS
(Default.)
Guess the encoding of the comment in the ZIP archive and convert it
to UTF-8, if necessary.
(Only CP-437 and UTF-8 are recognized.)
.It Dv ZIP_FL_ENC_STRICT
Follow the ZIP specification for file names and extend it to file
comments, expecting them to be encoded in CP-437 in the ZIP archive
(except if it is a UTF-8 comment from the special extra field).
Convert it to UTF-8.
.El
.Em Note :
ASCII is a subset of both CP-437 and UTF-8.
.Sh RETURN VALUES
Upon successful completion, a pointer to the comment is returned,
or
.Dv NULL
if there is no comment.
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_get_comment
fails if:
.Bl -tag -width Er
.It Bq Er ZIP_ER_INVAL
.Ar index
is not a valid file index in
.Ar archive .
.El
.Sh SEE ALSO
.Xr libzip 3 ,
.Xr zip_file_set_comment 3 ,
.Xr zip_get_archive_comment 3
.Sh HISTORY
.Fn zip_file_get_comment
was 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