doccmd 2026.3.26.2

Installation

$ pip install doccmd

$ brew tap adamtheturtle/doccmd
$ brew install doccmd

$ winget install --id adamtheturtle.doccmd --source winget --exact

$ curl --fail -L https://github.com/adamtheturtle/doccmd/releases/download/2026.03.26.1/doccmd-linux -o /usr/local/bin/doccmd &&
    chmod +x /usr/local/bin/doccmd

$ curl --fail -L https://github.com/adamtheturtle/doccmd/releases/download/2026.03.26.1/doccmd-macos -o /usr/local/bin/doccmd &&
    chmod +x /usr/local/bin/doccmd

$ curl --fail -L https://github.com/adamtheturtle/doccmd/releases/download/2026.03.26.1/doccmd-macos -o /usr/local/bin/doccmd &&
    chmod +x /usr/local/bin/doccmd

$ xattr -d com.apple.quarantine /usr/local/bin/doccmd

$ docker run --rm -v "$(pwd):/workdir" -w /workdir "ghcr.io/adamtheturtle/doccmd" --help

$ nix --extra-experimental-features 'nix-command flakes' run "github:adamtheturtle/doccmd/2026.03.26.1" -- --help

{
  inputs.doccmd.url = "github:adamtheturtle/doccmd";
}

-   repo: https://github.com/adamtheturtle/doccmd-pre-commit
    rev: v2026.3.26.1
    hooks:
    -   id: doccmd
        args: ["--language", "shell", "--command", "shellcheck --shell=bash"]
        additional_dependencies: ["shellcheck-py"]

Usage example

# Run mypy against the Python code blocks in README.md and CHANGELOG.rst
$ doccmd --language=python --command="mypy" README.md CHANGELOG.rst

# Run gofmt against the Go code blocks in README.md
# This will modify the README.md file in place
$ doccmd --language=go --command="gofmt -w" README.md

# or type less... and search for files in the docs directory
$ doccmd -l python -c mypy README.md docs/

# Run ruff format against the code blocks in a Markdown file
# Don't "pad" the code blocks with newlines - the formatter wouldn't like that.
# See the documentation about groups for more information.
$ doccmd --language=python --no-pad-file --no-pad-groups --command="ruff format" README.md

# Run j2lint against the sphinx-jinja2 code blocks in a MyST file
$ doccmd --sphinx-jinja2 --no-pad-file --command="j2lint" README.md

# Run ruff format against the pycon (Python interactive console) code blocks in README.rst
# doccmd strips the >>> prompts before running the formatter and restores them afterward
$ doccmd --language=pycon --no-pad-file --command="ruff format" README.rst

# Run ruff format against python blocks, auto-detecting which ones are pycon
# (use this if your existing docs label interactive sessions as "python" rather than "pycon")
$ doccmd --language=python --no-pad-file --command="ruff format" README.rst

What does it work on?

• reStructuredText (.rst)

.. code-block:: shell

   echo "Hello, world!"

.. code:: shell

   echo "Or this Hello, world!"

• Markdown (.md)

By default, .md files are treated as MyST files. To treat them as Markdown, use --myst-extension=. --markdown-extension=.md.

```shell
echo "Hello, world!"
```

• MyST (.md with MyST syntax)

```{code-block} shell
echo "Hello, world!"
```

```{code} shell
echo "Or this Hello, world!"
```

```{code-cell} shell
echo "Or this code-cell!"
```

• MDX (.mdx)

.mdx files are supported out of the box. Use --mdx-extension if you need additional suffixes.

```javascript
console.log("Hello, MDX!")
```

• Djot (.dj)

.dj files are supported out of the box. Use --djot-extension if you need additional suffixes.

```shell
echo "Hello, Djot!"
```

• Norg (.norg)

.norg files are supported out of the box. Use --norg-extension if you need additional suffixes.

@code shell
echo "Hello, Norg!"
@end

• Want more? Open an issue!

Formatters and padding

Running linters with doccmd gives you errors and warnings with line numbers that match the documentation file. It does this by adding padding to the code blocks before running the command.

Some tools do not work well with this padding, and you can choose to obscure the line numbers in order to give the tool the original code block’s content without padding, by using the --no-pad-file and --no-pad-groups flag. See using_groups_with_formatters for more information.

pycon code blocks

When --language=pycon is used, doccmd strips >>> and ... prompts before passing the code to the tool, and restores them afterward, preserving output lines. This allows linters and formatters that expect plain Python source to work on pycon blocks.

The recommended approach is to label interactive Python sessions in your documentation as pycon, keeping them clearly distinct from plain python blocks.

If your existing documentation already uses python as the language for both plain code and interactive sessions, use --detect-pycon-language=python (the default) together with --language=python. doccmd will automatically detect which python blocks are interactive (by checking whether the first non-empty line starts with >>>), and apply pycon stripping only to those. Plain python blocks are processed without stripping.

File names and linter ignores

doccmd creates temporary files for each code block in the documentation file. These files are created in the same directory as the documentation file, and are named with the documentation file name and the line number of the code block. Files are created with a prefix set to the given --temporary-file-name-prefix argument (default doccmd).

You can use this information to ignore files in your linter configuration.

For example, to ignore a rule in all files created by doccmd in a ruff configuration in pyproject.toml:

[tool.ruff]

lint.per-file-ignores."doccmd_*.py" = [
   # Allow hardcoded secrets in documentation.
   "S105",
]

Running commands in parallel

When doccmd is not writing formatter output back into your documentation files (i.e. you are using --no-write-to-file), you can speed things up by parallelizing both within a document and across documents.

• --example-workers evaluates multiple code blocks from the same document at once.

• --document-workers runs different documents concurrently.

Set either option to 0 to auto-detect a worker count based on the number of CPUs on your machine.

For example, doccmd --no-write-to-file --example-workers 4 --document-workers 2 spreads work across two documents, with up to four blocks active per document. This is handy for CPU-bound linters that only emit diagnostics.

Parallel execution is intentionally disabled whenever --write-to-file is in effect, since doccmd cannot safely merge formatter changes into the original documents out of order. Command output might interleave between example workers and document workers, so stick to the default sequential mode when deterministic stdout/stderr ordering is important.

Skipping code blocks

Code blocks which come just after a comment matching skip doccmd[all]: next are skipped.

To skip multiple code blocks in a row, use skip doccmd[all]: start and skip doccmd[all]: end comments surrounding the code blocks to skip.

Use the --skip-marker option to set a marker for this particular command which will work as well as all. For example, use --skip-marker="type-check" to skip code blocks which come just after a comment matching skip doccmd[type-check]: next.

To skip a code block for each of multiple markers, for example to skip a code block for the type-check and lint markers but not all markers, add multiple skip doccmd comments above the code block.

The skip comment will skip the next code block which would otherwise be run. This means that if you run doccmd with --language=python, the Python code block in the following Markdown or MDX example will be skipped:

<-- skip doccmd[all]: next -->

```{code-block} shell
echo "This will not run because the shell language was not selected"
```

```{code-block} python
print("This will be skipped!")
```

Therefore it is not recommended to use skip doccmd[all] and to instead use a more specific marker. For example, if we used doccmd with --language=shell and --skip-marker=echo the following examples show how to skip code blocks in different formats:

• reStructuredText (.rst)

.. skip doccmd[echo]: next

.. code-block:: shell

   echo "This will be skipped!"

.. code-block:: shell

   echo "This will run"

• Markdown (.md) and MDX (.mdx)

<-- skip doccmd[echo]: next -->

```shell
echo "This will be skipped!"
```

```shell
echo "This will run"
```

• MyST (.md with MyST syntax)

% skip doccmd[echo]: next

```{code-block} shell
echo "This will be skipped!"
```

```{code-block} shell
echo "This will run"
```

Grouping code blocks

"""Example function which is used in a future code block."""


def my_function() -> None:
    """Do nothing."""

my_function()

"""Example function which is used in a future code block."""


def my_function() -> None:
    """Do nothing."""

my_function()

```python group="example1"
def my_function():
    return "Hello"
```

```python group="example2"
def other_function():
    return "World"
```

```python group="example1"
result = my_function()
```

.. invisible-code-block: java

<!-- invisible-code-block: java

-->

Full documentation

See the full documentation.