LIBXO(3)

NAME
xo_attr, xo_attr_h, xo_attr_hv - Add attribute name/value pairs to formatted output

LIBRARY
libxo

SYNOPSIS
#include <libxo/xo.h>
xo_ssize_t
xo_attr(const char *name, const char *fmt, ...);
xo_ssize_t
xo_attr_h(xo_handle_t *handle, const char *name, const char *fmt, ...);
xo_ssize_t
xo_attr_hv(xo_handle_t *handle, const char *name, const char *fmt, va_list vap);

DESCRIPTION
The xo_attr() function emits attributes for the XML output style. The attribute value is recorded in the handle and is attached to the next field that is emitted via a xo_emit(3) call.

The name parameter give the name of the attribute to be encoded. The fmt parameter gives a printf-style format string used to format the value of the attribute using any remaining arguments, or the vap parameter as passed to xo_attr_hv().

        EXAMPLE:
          xo_attr("seconds", "%ld", (unsigned long) login_time);
          struct tm *tmp = localtime(login_time);
          strftime(buf, sizeof(buf), "%R", tmp);
          xo_emit("Logged in at {:login-time}\n", buf);
        XML:
            <login-time seconds="1408336270">00:14</login-time>

Since attributes are only emitted in XML, their use should be limited to meta-data and additional or redundant representations of data already emitted in other form.

SEE ALSO
xo_emit(3), libxo(3)

HISTORY
The libxo library first appeared in FreeBSD 11.0.

AUTHORS
libxo was written by Phil Shafer <phil@freebsd.org>.