xo_emit_hv(3)

xo_emit_hv3

Emit formatted output based on format string and arguments

Part of xo_emit(3).

Usage

xo_ssize_t

xo_ssize_t

xo_ssize_t

Library

library “libxo”

Overview

The xo_emit() function emits formatted output using the description in a format string along with a set of zero or more arguments, in a style similar to printf(3) but using a more complex format description string, as described in xo_format(5).

xo_emit() uses the default output handle, as described in libxo(3), where xo_emit_h() uses an explicit handle. xo_emit_hv() accepts a va_list for additional flexibility.

Examples

In this example, a set of four values is emitted using the following source code:

    xo_emit(" {:lines/%7ju} {:words/%7ju} "
            "{:characters/%7ju} {d:filename/%s}\n",
            linect, wordct, charct, file);

Output can then be generated in various style, using the "--libxo" option:

    % wc /etc/motd
          25     165    1140 /etc/motd
    % wc --libxo xml,pretty,warn /etc/motd
    <wc>
      <file>
        <lines>25</lines>
        <words>165</words>
        <characters>1140</characters>
        <filename>/etc/motd</filename>
      </file>
    </wc>
    % wc --libxo json,pretty,warn /etc/motd
    {
      "wc": {
        "file": [
          {
            "lines": 25,
            "words": 165,
            "characters": 1140,
            "filename": "/etc/motd"
          }
        ]
      }
    }
    % wc --libxo html,pretty,warn /etc/motd
    <div class="line">
      <div class="text"> </div>
      <div class="data" data-tag="lines">     25</div>
      <div class="text"> </div>
      <div class="data" data-tag="words">    165</div>
      <div class="text"> </div>
      <div class="data" data-tag="characters">   1140</div>
      <div class="text"> </div>
      <div class="data" data-tag="filename">/etc/motd</div>
    </div>

Return code

xo_emit returns a negative value on error. If the XOF_COLUMNS flag has been turned on for the specific handle using xo_set_flags(3), then the number of display columns consumed by the output will be returned.

Releases

25 releases since FreeBSD 11.0-RELEASE; the text changed 3 times.

  1. 11.0–11.1
  2. 11.2–12.4
  3. 13.0–13.5
  4. 14.0–16.0

History

The libxo library first appeared in FreeBSD 11.0.

Authors

libxo was written by Phil Shafer ⟨[email protected]⟩.

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.