path: root/man/man3/cmark.3

.TH cmark 3 "March 19, 2019" "LOCAL" "Library Functions Manual"
.SH
NAME
.PP
\f[B]cmark\f[] \- CommonMark parsing, manipulating, and rendering

.SH
DESCRIPTION
.SS
Simple Interface

.PP
\fIchar *\f[] \fBcmark_markdown_to_html\f[](\fIconst char *text\f[], \fIsize_t len\f[], \fIint options\f[])

.PP
Convert \f[I]text\f[] (assumed to be a UTF\-8 encoded string with length
\f[I]len\f[]) from CommonMark Markdown to HTML, returning a
null\-terminated, UTF\-8\-encoded string. It is the caller's
responsibility to free the returned buffer.

.SS
Node Structure

.PP
.nf
\fC
.RS 0n
typedef enum {
  /* Error status */
  CMARK_NODE_NONE,

  /* Block */
  CMARK_NODE_DOCUMENT,
  CMARK_NODE_BLOCK_QUOTE,
  CMARK_NODE_LIST,
  CMARK_NODE_ITEM,
  CMARK_NODE_CODE_BLOCK,
  CMARK_NODE_HTML_BLOCK,
  CMARK_NODE_CUSTOM_BLOCK,
  CMARK_NODE_PARAGRAPH,
  CMARK_NODE_HEADING,
  CMARK_NODE_THEMATIC_BREAK,

  CMARK_NODE_FIRST_BLOCK = CMARK_NODE_DOCUMENT,
  CMARK_NODE_LAST_BLOCK = CMARK_NODE_THEMATIC_BREAK,

  /* Inline */
  CMARK_NODE_TEXT,
  CMARK_NODE_SOFTBREAK,
  CMARK_NODE_LINEBREAK,
  CMARK_NODE_CODE,
  CMARK_NODE_HTML_INLINE,
  CMARK_NODE_CUSTOM_INLINE,
  CMARK_NODE_EMPH,
  CMARK_NODE_STRONG,
  CMARK_NODE_LINK,
  CMARK_NODE_IMAGE,

  CMARK_NODE_FIRST_INLINE = CMARK_NODE_TEXT,
  CMARK_NODE_LAST_INLINE = CMARK_NODE_IMAGE,
} cmark_node_type;
.RE
\f[]
.fi



.PP
.nf
\fC
.RS 0n
typedef enum {
  CMARK_NO_LIST,
  CMARK_BULLET_LIST,
  CMARK_ORDERED_LIST
} cmark_list_type;
.RE
\f[]
.fi



.PP
.nf
\fC
.RS 0n
typedef enum {
  CMARK_NO_DELIM,
  CMARK_PERIOD_DELIM,
  CMARK_PAREN_DELIM
} cmark_delim_type;
.RE
\f[]
.fi



.SS
Custom memory allocator support

.PP
.nf
\fC
.RS 0n
typedef struct cmark_mem {
  void *(*calloc)(size_t, size_t);
  void *(*realloc)(void *, size_t);
  void (*free)(void *);
} cmark_mem;
.RE
\f[]
.fi

.PP
Defines the memory allocation functions to be used by CMark when parsing
and allocating a document tree

.SS
Creating and Destroying Nodes

.PP
\fIcmark_node *\f[] \fBcmark_node_new\f[](\fIcmark_node_type type\f[])

.PP
Creates a new node of type \f[I]type\f[]. Note that the node may have
other required properties, which it is the caller's responsibility to
assign.

.PP
\fIcmark_node *\f[] \fBcmark_node_new_with_mem\f[](\fIcmark_node_type type\f[], \fIcmark_mem *mem\f[])

.PP
Same as \f[C]cmark_node_new\f[], but explicitly listing the memory
allocator used to allocate the node. Note: be sure to use the same
allocator for every node in a tree, or bad things can happen.

.PP
\fIvoid\f[] \fBcmark_node_free\f[](\fIcmark_node *node\f[])

.PP
Frees the memory allocated for a node and any children.

.SS
Tree Traversal

.PP
\fIcmark_node *\f[] \fBcmark_node_next\f[](\fIcmark_node *node\f[])

.PP
Returns the next node in the sequence after \f[I]node\f[], or NULL if
there is none.

.PP
\fIcmark_node *\f[] \fBcmark_node_previous\f[](\fIcmark_node *node\f[])

.PP
Returns the previous node in the sequence after \f[I]node\f[], or NULL
if there is none.

.PP
\fIcmark_node *\f[] \fBcmark_node_parent\f[](\fIcmark_node *node\f[])

.PP
Returns the parent of \f[I]node\f[], or NULL if there is none.

.PP
\fIcmark_node *\f[] \fBcmark_node_first_child\f[](\fIcmark_node *node\f[])

.PP
Returns the first child of \f[I]node\f[], or NULL if \f[I]node\f[] has
no children.

.PP
\fIcmark_node *\f[] \fBcmark_node_last_child\f[](\fIcmark_node *node\f[])

.PP
Returns the last child of \f[I]node\f[], or NULL if \f[I]node\f[] has no
children.

.SS
Iterator
.PP
An iterator will walk through a tree of nodes, starting from a root
node, returning one node at a time, together with information about
whether the node is being entered or exited. The iterator will first
descend to a child node, if there is one. When there is no child, the
iterator will go to the next sibling. When there is no next sibling, the
iterator will return to the parent (but with a \f[I]cmark_event_type\f[]
of \f[C]CMARK_EVENT_EXIT\f[]). The iterator will return
\f[C]CMARK_EVENT_DONE\f[] when it reaches the root node again. One
natural application is an HTML renderer, where an \f[C]ENTER\f[] event
outputs an open tag and an \f[C]EXIT\f[] event outputs a close tag. An
iterator might also be used to transform an AST in some systematic way,
for example, turning all level\-3 headings into regular paragraphs.
.IP
.nf
\f[C]
void
usage_example(cmark_node *root) {
    cmark_event_type ev_type;
    cmark_iter *iter = cmark_iter_new(root);

    while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
        cmark_node *cur = cmark_iter_get_node(iter);
        // Do something with `cur` and `ev_type`
    }

    cmark_iter_free(iter);
}
\f[]
.fi
.PP
Iterators will never return \f[C]EXIT\f[] events for leaf nodes, which
are nodes of type:
.IP \[bu] 2
CMARK_NODE_HTML_BLOCK
.IP \[bu] 2
CMARK_NODE_THEMATIC_BREAK
.IP \[bu] 2
CMARK_NODE_CODE_BLOCK
.IP \[bu] 2
CMARK_NODE_TEXT
.IP \[bu] 2
CMARK_NODE_SOFTBREAK
.IP \[bu] 2
CMARK_NODE_LINEBREAK
.IP \[bu] 2
CMARK_NODE_CODE
.IP \[bu] 2
CMARK_NODE_HTML_INLINE
.PP
Nodes must only be modified after an \f[C]EXIT\f[] event, or an
\f[C]ENTER\f[] event for leaf nodes.

.PP
.nf
\fC
.RS 0n
typedef enum {
  CMARK_EVENT_NONE,
  CMARK_EVENT_DONE,
  CMARK_EVENT_ENTER,
  CMARK_EVENT_EXIT
} cmark_event_type;
.RE
\f[]
.fi



.PP
\fIcmark_iter *\f[] \fBcmark_iter_new\f[](\fIcmark_node *root\f[])

.PP
Creates a new iterator starting at \f[I]root\f[]. The current node and
event type are undefined until \f[I]cmark_iter_next\f[] is called for
the first time. The memory allocated for the iterator should be released
using \f[I]cmark_iter_free\f[] when it is no longer needed.

.PP
\fIvoid\f[] \fBcmark_iter_free\f[](\fIcmark_iter *iter\f[])

.PP
Frees the memory allocated for an iterator.

.PP
\fIcmark_event_type\f[] \fBcmark_iter_next\f[](\fIcmark_iter *iter\f[])

.PP
Advances to the next node and returns the event type
(\f[C]CMARK_EVENT_ENTER\f[], \f[C]CMARK_EVENT_EXIT\f[] or
\f[C]CMARK_EVENT_DONE\f[]).

.PP
\fIcmark_node *\f[] \fBcmark_iter_get_node\f[](\fIcmark_iter *iter\f[])

.PP
Returns the current node.

.PP
\fIcmark_event_type\f[] \fBcmark_iter_get_event_type\f[](\fIcmark_iter *iter\f[])

.PP
Returns the current event type.

.PP
\fIcmark_node *\f[] \fBcmark_iter_get_root\f[](\fIcmark_iter *iter\f[])

.PP
Returns the root node.

.PP
\fIvoid\f[] \fBcmark_iter_reset\f[](\fIcmark_iter *iter\f[], \fIcmark_node *current\f[], \fIcmark_event_type event_type\f[])

.PP
Resets the iterator so that the current node is \f[I]current\f[] and the
event type is \f[I]event_type\f[]. The new current node must be a
descendant of the root node or the root node itself.

.SS
Accessors

.PP
\fIvoid *\f[] \fBcmark_node_get_user_data\f[](\fIcmark_node *node\f[])

.PP
Returns the user data of \f[I]node\f[].

.PP
\fIint\f[] \fBcmark_node_set_user_data\f[](\fIcmark_node *node\f[], \fIvoid *user_data\f[])

.PP
Sets arbitrary user data for \f[I]node\f[]. Returns 1 on success, 0 on
failure.

.PP
\fIcmark_node_type\f[] \fBcmark_node_get_type\f[](\fIcmark_node *node\f[])

.PP
Returns the type of \f[I]node\f[], or \f[C]CMARK_NODE_NONE\f[] on error.

.PP
\fIconst char *\f[] \fBcmark_node_get_type_string\f[](\fIcmark_node *node\f[])

.PP
Like \f[I]cmark_node_get_type\f[], but returns a string representation
of the type, or \f[C]"<unknown>"\f[].

.PP
\fIconst char *\f[] \fBcmark_node_get_literal\f[](\fIcmark_node *node\f[])

.PP
Returns the string contents of \f[I]node\f[], or an empty string if none
is set. Returns NULL if called on a node that does not have string
content.

.PP
\fIint\f[] \fBcmark_node_set_literal\f[](\fIcmark_node *node\f[], \fIconst char *content\f[])

.PP
Sets the string contents of \f[I]node\f[]. Returns 1 on success, 0 on
failure.

.PP
\fIint\f[] \fBcmark_node_get_heading_level\f[](\fIcmark_node *node\f[])

.PP
Returns the heading level of \f[I]node\f[], or 0 if \f[I]node\f[] is not
a heading.

.PP
\fIint\f[] \fBcmark_node_set_heading_level\f[](\fIcmark_node *node\f[], \fIint level\f[])

.PP
Sets the heading level of \f[I]node\f[], returning 1 on success and 0 on
error.

.PP
\fIcmark_list_type\f[] \fBcmark_node_get_list_type\f[](\fIcmark_node *node\f[])

.PP
Returns the list type of \f[I]node\f[], or \f[C]CMARK_NO_LIST\f[] if
\f[I]node\f[] is not a list.

.PP
\fIint\f[] \fBcmark_node_set_list_type\f[](\fIcmark_node *node\f[], \fIcmark_list_type type\f[])

.PP
Sets the list type of \f[I]node\f[], returning 1 on success and 0 on
error.

.PP
\fIcmark_delim_type\f[] \fBcmark_node_get_list_delim\f[](\fIcmark_node *node\f[])

.PP
Returns the list delimiter type of \f[I]node\f[], or
\f[C]CMARK_NO_DELIM\f[] if \f[I]node\f[] is not a list.

.PP
\fIint\f[] \fBcmark_node_set_list_delim\f[](\fIcmark_node *node\f[], \fIcmark_delim_type delim\f[])

.PP
Sets the list delimiter type of \f[I]node\f[], returning 1 on success
and 0 on error.

.PP
\fIint\f[] \fBcmark_node_get_list_start\f[](\fIcmark_node *node\f[])

.PP
Returns starting number of \f[I]node\f[], if it is an ordered list,
otherwise 0.

.PP
\fIint\f[] \fBcmark_node_set_list_start\f[](\fIcmark_node *node\f[], \fIint start\f[])

.PP
Sets starting number of \f[I]node\f[], if it is an ordered list.
Returns 1 on success, 0 on failure.

.PP
\fIint\f[] \fBcmark_node_get_list_tight\f[](\fIcmark_node *node\f[])

.PP
Returns 1 if \f[I]node\f[] is a tight list, 0 otherwise.

.PP
\fIint\f[] \fBcmark_node_set_list_tight\f[](\fIcmark_node *node\f[], \fIint tight\f[])

.PP
Sets the "tightness" of a list. Returns 1 on success, 0 on failure.

.PP
\fIconst char *\f[] \fBcmark_node_get_fence_info\f[](\fIcmark_node *node\f[])

.PP
Returns the info string from a fenced code block.

.PP
\fIint\f[] \fBcmark_node_set_fence_info\f[](\fIcmark_node *node\f[], \fIconst char *info\f[])

.PP
Sets the info string in a fenced code block, returning 1 on success
and 0 on failure.

.PP
\fIconst char *\f[] \fBcmark_node_get_url\f[](\fIcmark_node *node\f[])

.PP
Returns the URL of a link or image \f[I]node\f[], or an empty string if
no URL is set. Returns NULL if called on a node that is not a link or
image.

.PP
\fIint\f[] \fBcmark_node_set_url\f[](\fIcmark_node *node\f[], \fIconst char *url\f[])

.PP
Sets the URL of a link or image \f[I]node\f[]. Returns 1 on success, 0
on failure.

.PP
\fIconst char *\f[] \fBcmark_node_get_title\f[](\fIcmark_node *node\f[])

.PP
Returns the title of a link or image \f[I]node\f[], or an empty string
if no title is set. Returns NULL if called on a node that is not a link
or image.

.PP
\fIint\f[] \fBcmark_node_set_title\f[](\fIcmark_node *node\f[], \fIconst char *title\f[])

.PP
Sets the title of a link or image \f[I]node\f[]. Returns 1 on success, 0
on failure.

.PP
\fIconst char *\f[] \fBcmark_node_get_on_enter\f[](\fIcmark_node *node\f[])

.PP
Returns the literal "on enter" text for a custom \f[I]node\f[], or an
empty string if no on_enter is set. Returns NULL if called on a
non\-custom node.

.PP
\fIint\f[] \fBcmark_node_set_on_enter\f[](\fIcmark_node *node\f[], \fIconst char *on_enter\f[])

.PP
Sets the literal text to render "on enter" for a custom \f[I]node\f[].
Any children of the node will be rendered after this text. Returns 1 on
success 0 on failure.

.PP
\fIconst char *\f[] \fBcmark_node_get_on_exit\f[](\fIcmark_node *node\f[])

.PP
Returns the literal "on exit" text for a custom \f[I]node\f[], or an
empty string if no on_exit is set. Returns NULL if called on a
non\-custom node.

.PP
\fIint\f[] \fBcmark_node_set_on_exit\f[](\fIcmark_node *node\f[], \fIconst char *on_exit\f[])

.PP
Sets the literal text to render "on exit" for a custom \f[I]node\f[].
Any children of the node will be rendered before this text. Returns 1 on
success 0 on failure.

.PP
\fIint\f[] \fBcmark_node_get_start_line\f[](\fIcmark_node *node\f[])

.PP
Returns the line on which \f[I]node\f[] begins.

.PP
\fIint\f[] \fBcmark_node_get_start_column\f[](\fIcmark_node *node\f[])

.PP
Returns the column at which \f[I]node\f[] begins.

.PP
\fIint\f[] \fBcmark_node_get_end_line\f[](\fIcmark_node *node\f[])

.PP
Returns the line on which \f[I]node\f[] ends.

.PP
\fIint\f[] \fBcmark_node_get_end_column\f[](\fIcmark_node *node\f[])

.PP
Returns the column at which \f[I]node\f[] ends.

.SS
Tree Manipulation

.PP
\fIvoid\f[] \fBcmark_node_unlink\f[](\fIcmark_node *node\f[])

.PP
Unlinks a \f[I]node\f[], removing it from the tree, but not freeing its
memory. (Use \f[I]cmark_node_free\f[] for that.)

.PP
\fIint\f[] \fBcmark_node_insert_before\f[](\fIcmark_node *node\f[], \fIcmark_node *sibling\f[])

.PP
Inserts \f[I]sibling\f[] before \f[I]node\f[]. Returns 1 on success, 0
on failure.

.PP
\fIint\f[] \fBcmark_node_insert_after\f[](\fIcmark_node *node\f[], \fIcmark_node *sibling\f[])

.PP
Inserts \f[I]sibling\f[] after \f[I]node\f[]. Returns 1 on success, 0 on
failure.

.PP
\fIint\f[] \fBcmark_node_replace\f[](\fIcmark_node *oldnode\f[], \fIcmark_node *newnode\f[])

.PP
Replaces \f[I]oldnode\f[] with \f[I]newnode\f[] and unlinks
\f[I]oldnode\f[] (but does not free its memory). Returns 1 on success, 0
on failure.

.PP
\fIint\f[] \fBcmark_node_prepend_child\f[](\fIcmark_node *node\f[], \fIcmark_node *child\f[])

.PP
Adds \f[I]child\f[] to the beginning of the children of \f[I]node\f[].
Returns 1 on success, 0 on failure.

.PP
\fIint\f[] \fBcmark_node_append_child\f[](\fIcmark_node *node\f[], \fIcmark_node *child\f[])

.PP
Adds \f[I]child\f[] to the end of the children of \f[I]node\f[].
Returns 1 on success, 0 on failure.

.PP
\fIvoid\f[] \fBcmark_consolidate_text_nodes\f[](\fIcmark_node *root\f[])

.PP
Consolidates adjacent text nodes.

.SS
Parsing
.PP
Simple interface:
.IP
.nf
\f[C]
cmark_node *document = cmark_parse_document("Hello *world*", 13,
                                            CMARK_OPT_DEFAULT);
\f[]
.fi
.PP
Streaming interface:
.IP
.nf
\f[C]
cmark_parser *parser = cmark_parser_new(CMARK_OPT_DEFAULT);
FILE *fp = fopen("myfile.md", "rb");
while ((bytes = fread(buffer, 1, sizeof(buffer), fp)) > 0) {
	   cmark_parser_feed(parser, buffer, bytes);
	   if (bytes < sizeof(buffer)) {
	       break;
	   }
}
document = cmark_parser_finish(parser);
cmark_parser_free(parser);
\f[]
.fi

.PP
\fIcmark_parser *\f[] \fBcmark_parser_new\f[](\fIint options\f[])

.PP
Creates a new parser object.

.PP
\fIcmark_parser *\f[] \fBcmark_parser_new_with_mem\f[](\fIint options\f[], \fIcmark_mem *mem\f[])

.PP
Creates a new parser object with the given memory allocator

.PP
\fIvoid\f[] \fBcmark_parser_free\f[](\fIcmark_parser *parser\f[])

.PP
Frees memory allocated for a parser object.

.PP
\fIvoid\f[] \fBcmark_parser_feed\f[](\fIcmark_parser *parser\f[], \fIconst char *buffer\f[], \fIsize_t len\f[])

.PP
Feeds a string of length \f[I]len\f[] to \f[I]parser\f[].

.PP
\fIcmark_node *\f[] \fBcmark_parser_finish\f[](\fIcmark_parser *parser\f[])

.PP
Finish parsing and return a pointer to a tree of nodes.

.PP
\fIcmark_node *\f[] \fBcmark_parse_document\f[](\fIconst char *buffer\f[], \fIsize_t len\f[], \fIint options\f[])

.PP
Parse a CommonMark document in \f[I]buffer\f[] of length \f[I]len\f[].
Returns a pointer to a tree of nodes. The memory allocated for the node
tree should be released using \f[I]cmark_node_free\f[] when it is no
longer needed.

.PP
\fIcmark_node *\f[] \fBcmark_parse_file\f[](\fIFILE *f\f[], \fIint options\f[])

.PP
Parse a CommonMark document in file \f[I]f\f[], returning a pointer to a
tree of nodes. The memory allocated for the node tree should be released
using \f[I]cmark_node_free\f[] when it is no longer needed.

.SS
Rendering

.PP
\fIchar *\f[] \fBcmark_render_xml\f[](\fIcmark_node *root\f[], \fIint options\f[])

.PP
Render a \f[I]node\f[] tree as XML. It is the caller's responsibility to
free the returned buffer.

.PP
\fIchar *\f[] \fBcmark_render_html\f[](\fIcmark_node *root\f[], \fIint options\f[])

.PP
Render a \f[I]node\f[] tree as an HTML fragment. It is up to the user to
add an appropriate header and footer. It is the caller's responsibility
to free the returned buffer.

.PP
\fIchar *\f[] \fBcmark_render_man\f[](\fIcmark_node *root\f[], \fIint options\f[], \fIint width\f[])

.PP
Render a \f[I]node\f[] tree as a groff man page, without the header. It
is the caller's responsibility to free the returned buffer.

.PP
\fIchar *\f[] \fBcmark_render_commonmark\f[](\fIcmark_node *root\f[], \fIint options\f[], \fIint width\f[])

.PP
Render a \f[I]node\f[] tree as a commonmark document. It is the caller's
responsibility to free the returned buffer.

.PP
\fIchar *\f[] \fBcmark_render_latex\f[](\fIcmark_node *root\f[], \fIint options\f[], \fIint width\f[])

.PP
Render a \f[I]node\f[] tree as a LaTeX document. It is the caller's
responsibility to free the returned buffer.

.SS
Options

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_DEFAULT 0
.RE
\f[]
.fi

.PP
Default options.

.SS
Options affecting rendering

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_SOURCEPOS (1 << 1)
.RE
\f[]
.fi

.PP
Include a \f[C]data\-sourcepos\f[] attribute on all block elements.

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_HARDBREAKS (1 << 2)
.RE
\f[]
.fi

.PP
Render \f[C]softbreak\f[] elements as hard line breaks.

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_SAFE (1 << 3)
.RE
\f[]
.fi

.PP
\f[C]CMARK_OPT_SAFE\f[] is defined here for API compatibility, but it no
longer has any effect. "Safe" mode is now the default: set
\f[C]CMARK_OPT_UNSAFE\f[] to disable it.

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_UNSAFE (1 << 17)
.RE
\f[]
.fi

.PP
Render raw HTML and unsafe links (\f[C]javascript:\f[],
\f[C]vbscript:\f[], \f[C]file:\f[], and \f[C]data:\f[], except for
\f[C]image/png\f[], \f[C]image/gif\f[], \f[C]image/jpeg\f[], or
\f[C]image/webp\f[] mime types). By default, raw HTML is replaced by a
placeholder HTML comment. Unsafe links are replaced by empty strings.

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_NOBREAKS (1 << 4)
.RE
\f[]
.fi

.PP
Render \f[C]softbreak\f[] elements as spaces.

.SS
Options affecting parsing

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_NORMALIZE (1 << 8)
.RE
\f[]
.fi

.PP
Legacy option (no effect).

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_VALIDATE_UTF8 (1 << 9)
.RE
\f[]
.fi

.PP
Validate UTF\-8 in the input before parsing, replacing illegal sequences
with the replacement character U+FFFD.

.PP
.nf
\fC
.RS 0n
#define CMARK_OPT_SMART (1 << 10)
.RE
\f[]
.fi

.PP
Convert straight quotes to curly, \-\-\- to em dashes, \-\- to en
dashes.

.SS
Version information

.PP
\fIint\f[] \fBcmark_version\f[](\fIvoid\f[])

.PP
The library version as integer for runtime checks. Also available as
macro CMARK_VERSION for compile time checks.
.IP \[bu] 2
Bits 16\-23 contain the major version.
.IP \[bu] 2
Bits 8\-15 contain the minor version.
.IP \[bu] 2
Bits 0\-7 contain the patchlevel.
.PP
In hexadecimal format, the number 0x010203 represents version 1.2.3.

.PP
\fIconst char *\f[] \fBcmark_version_string\f[](\fIvoid\f[])

.PP
The library version string for runtime checks. Also available as macro
CMARK_VERSION_STRING for compile time checks.

.SH
AUTHORS
.PP
John MacFarlane, Vicent Marti, Kārlis Gaņģis, Nick Wellnhofer.