KHTML_ATTR(3) Library Functions Manual KHTML_ATTR(3)

khtml_attr, khtml_attrxopen an element scope for kcgihtml

library “libkcgihtml”

#include <sys/types.h>
#include <stdarg.h>
#include <stdint.h>
#include <kcgi.h>
#include <kcgihtml.h>

enum kcgi_err
khtml_attr(struct khtmlreq *req, enum kelem elem, ...);

enum kcgi_err
khtml_attrx(struct khtmlreq *req, enum kelem elem, ...);

Open a new scope of element elem on the current element stack of req, initialised with khtml_open(3). Scopes are closed with khtml_closeelem(3), khtml_closeto(3), or khtml_close(3). If elem is a "void" eleemnt (self-closing, like KELEM_LINK) or KELEM_DOCTYPE, the scope is immediately closed so no new scope is opened.

For (), variable arguments are in pairs, with the first of a pair being a enum attr of the attribute type and the second being a non-NULL string.

For (), variable arguments are in triplets: the first is a enum attr of the attribute type, the second is a enum attrx describing the data format of the third type, and the third type is either an int64_t, char *, or double for KATTRX_INT, KATTRX_STRING, or KATTRX_DOUBLE, respectively.

In both cases, string content is HTML escaped, for example, the double-quote character is rendered as "&quot;". This prevents arguments from "breaking" the attribute string context.

The variable arguments terminated with a singular KATTR__MAX.

Returns an enum kcgi_err indicating the error state.

Success (not an error).
Internal memory allocation failure, including reaching the maximum number of possible HTML scopes.
The output connection has been terminated. For FastCGI connections, the current connection should be released with khttp_free(3) and parse loop reentered.
The connection is still expecting headers with khttp_head(3). Indicates that khttp_body(3) did not return with success or was not invoked. For FastCGI connections, the current connection should be released with khttp_free(3) and parse loop reentered.
Internal system error writing to the output stream.

The following outputs a simple HTML page. It assumes r is a struct kreq pointer. For brevity, it does not do any error checking.

khttp_head(r, kresps[KRESP_STATUS],
  "%s", khttps[KHTTP_200]);
khttp_head(r, kresps[KRESP_CONTENT_TYPE],
  "%s", kmimetypes[KMIME_TEXT_HTML]);
khtml_open(&req, r, 0);
khtml_elem(&req, KELEM_DOCTYPE);
khtml_elem(&req, KELEM_HTML);
khtml_elem(&req, KELEM_HEAD);
khtml_attr(req, KELEM_META,
khtml_attrx(req, KELEM_LINK,
  KATTR_REL, KATTRX_STRING, "stylesheet",

The latter invocation could just as easily use khtml_attr().


The referenced HTML5 standard is HTML5.2.

Written by Kristaps Dzonsons <>.

September 23, 2021 OpenBSD 6.7