LIBXO(3)               FreeBSD Library Functions Manual               LIBXO(3)

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

LIBRARY
     Text, XML, JSON, and HTML Output Emission Library (libxo, -lxo)

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>.

FreeBSD 13.1-RELEASE-p6           July, 2014           FreeBSD 13.1-RELEASE-p6