.\"	$Id: lowdown_buf_diff.3,v 1.5 2021/01/26 10:43:06 kristaps Exp $
.\"
.\" Copyright (c) 2018, 2020 Kristaps Dzonsons <kristaps@bsd.lv>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
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.Dd $Mdocdate: January 26 2021 $
.Dt LOWDOWN_BUF_DIFF 3
.Os
.Sh NAME
.Nm lowdown_buf
.Nd parse and diff Markdown buffers into formatted output
.Sh LIBRARY
.Lb liblowdown
.Sh SYNOPSIS
.In sys/queue.h
.In stdio.h
.In lowdown.h
.Ft int
.Fo lowdown_buf_diff
.Fa "const struct lowdown_opts *opts"
.Fa "const char *new"
.Fa "size_t newsz"
.Fa "const char *old"
.Fa "size_t oldsz"
.Fa "char **ret"
.Fa "size_t *retsz"
.Fa "struct lowdown_metaq *metaq"
.Fc
.Sh DESCRIPTION
Parses
.Xr lowdown 5
buffers
.Fa new
of size
.Fa newsz
and
.Fa old
of size
.Fa oldsz
and produces an edit script in
.Fa ret
of size
.Fa retsz
according to configurations
.Fa opts .
The script defines differences from
.Fa old
to
.Fa new .
The output format is specified by
.Fa opts->type .
If
.Dv LOWDOWN_METADATA
is set in
.Fa opts->feat
and
.Fa metaq
is not
.Dv NULL ,
.Fa metaq
is filled with metadata rendered in the given output format.
.Pp
The caller is responsible for freeing
.Fa ret
and
.Fa metaq .
.Sh RETURN VALUES
Returns zero on failure, non-zero on success.
Failure occurs from memory exhaustion.
.Sh SEE ALSO
.Xr lowdown 3 ,
.Xr lowdown_metaq_free 3