---
name: "xo"
section: "1"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/xo"
---

# xo(1)

emit formatted output based on format string and arguments

## NAME

**xo** – emit formatted output based on format string and arguments

## SYNOPSIS

**xo** \[**-options**\] \[*argument...*\]

## DESCRIPTION

The **xo** utility allows command line access to the functionality of the **libxo** library. Using **xo**, shell scripts can emit *XML*, *JSON*, or *HTML* using the same commands that emit text output.

- **--close** *path*

  Close tags for the given path

- **-C** \| **--continuation**

  Indicates this output is a continuation of the previous output data and should appear on the same line. This is allows HTML output to be constructed correctly.

- **--depth** *num*

  Set the depth for pretty printing

- **--help**

  Display help text

- **-H** \| **--html**

  Generate HTML output

- **-J** \| **--json**

  Generate JSON output

- **--leading-xpath** *path*

  Add a prefix to generated XPaths (HTML)

- **--not-first**

  Indicate that this content is not the first in a series of sibling objects, which is vital information for "JSON" output, which requires a comma between such objects.

- **--open** *path*

  Open tags for the given path

- **-p** \| **--pretty**

  Make 'pretty' output (add indent, newlines)

- **--style** *style*

  Generate given style (xml, json, text, html)

- **-T** \| **--text**

  Generate text output (the default style)

- **--top-warp**

  Indicates the entire object should be placed inside a top-level object wrapper, specifically when generating JSON output.

- **--version**

  Display version information

- **-W** \| **--warn**

  Display warnings in text on stderr

- **--warn-xml**

  Display warnings in xml on stdout

- **--wrap** *path*

  Wrap output in a set of containers

- **-X** \| **--xml**

  Generate XML output

- **--xpath**

  Add XPath data to HTML output

The **xo** utility accepts a format string suitable for [xo\_emit(3)](/xo_emit/3.md) and a set of zero or more arguments used to supply data for that string.

In addition, **xo** accepts any of the **libxo** options listed in [xo\_options(7)](/xo_options/7.md).

## EXAMPLES

In this example, **xo** is used to emit the same data encoded in text and then in XML by adding the "-p" (pretty) and "-X" (XML output) flags:

```
  % xo 'The {:product} is {:status}\n' stereo "in route"
  The stereo is in route
  % xo -p -X 'The {:product} is {:status}\n' stereo "in route"
  <product>stereo</product>
  <status>in route</status>
```

In this example, the output from a **xo** command is shown in several styles:

```
  xo "The {k:name} weighs {:weight/%d} pounds.\n" fish 6
  TEXT:
    The fish weighs 6 pounds.
  XML:
    <name>fish</name>
    <weight>6</weight>
  JSON:
    "name": "fish",
    "weight": 6
  HTML:
    <div class="line">
      <div class="text">The </div>
      <div class="data" data-tag="name">fish</div>
      <div class="text"> weighs </div>
      <div class="data" data-tag="weight">6</div>
      <div class="text"> pounds.</div>
    </div>
```

The **--wrap \<path\>** option can be used to wrap emitted content in a specific hierarchy. The path is a set of hierarchical names separated by the '/' character.

```
  xo --wrap top/a/b/c '{:tag}' value
  XML:
    <top>
      <a>
        <b>
          <c>
            <tag>value</tag>
          </c>
        </b>
      </a>
    </top>
  JSON:
    "top": {
      "a": {
        "b": {
          "c": {
            "tag": "value"
          }
        }
      }
    }
```

The **--open \<path\>** and **--close \<path\>** can be used to emit hierarchical information without the matching close and open tag. This allows a shell script to emit open tags, data, and then close tags. The **--depth** option may be used to set the depth for indentation. The **--leading-xpath** may be used to prepend data to the XPath values used for HTML output style.

```
  #!/bin/sh
  xo --open top/data
  xo --depth 2 '{:tag}' value
  xo --close top/data
  XML:
    <top>
      <data>
        <tag>value</tag>
      </data>
    </top>
  JSON:
    "top": {
      "data": {
        "tag": "value"
      }
    }
```

## SEE ALSO

[libxo(3)](/libxo/3.md), [xo\_emit(3)](/xo_emit/3.md), [xo\_options(7)](/xo_options/7.md)

## HISTORY

The **libxo** library first appeared in FreeBSD 11.0.

## AUTHORS

**libxo** was written by Phil Shafer ⟨*phil@freebsd.org*⟩.