LIBXO(3)

💅 LIBXO(3) — okay bestie, it’s giving Library Functions Manual energy 💅

Hiiii so this is LIBXO(3) from the Library Functions Manual, and it’s lowkey a tiny page with one very specific job: adding attribute name/value pairs to formatted output. Slay. ✨

🎀 NAME 🎀

xo_attr, xo_attr_h, xo_attr_hv — Add attribute name/value pairs to formatted output. 💖

📚 LIBRARY 📚

library “libxo” — that’s the library, bestie. 🦋

✨ 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 💅

Okay so xo_attr() emits attributes for the XML output style — yes, XML specifically, no cap. The attribute value gets recorded in the handle and is attached to the next field that is emitted via a xo_emit(3) call. That’s the whole vibe. 🫶

The name parameter gives 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(). Cute, right? 😭

Here’s the example, preserved exactly because we do not play with code:

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>

And remember: 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. That’s the caveat, bestie — don’t make it weird. 💀

🔍 SEE ALSO 🔍

• xo_emit(3) — the emit call your attribute is waiting to attach to. 👑
• libxo(3) — the library page itself. 🌈

🕰️ HISTORY 🕰️

The libxo library first appeared in FreeBSD 11.0. Vintage-ish. ✨

💌 AUTHORS 💌

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

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Source/version: Debian. Date: July, 2014. Page: LIBXO(3). 🎀