Reference¶

Usage¶

$ jiren [OPTIONS] [TEMPLATE] [-- VARIABLE_OPTIONS]

TEMPLATE is a template file path. Omit it, or pass -, to read the template from standard input. Pass values for template variables after --.

Scalar values passed after -- are always strings. They do not inherit the type of a corresponding value loaded with --data: for example, --count=5 produces "5", and --enabled=false produces the truthy string "false". Use --data or --data-string when a variable needs a JSON or YAML type, such as a number, boolean, list, or object.

Render a template¶

Read a template from standard input:

$ echo "hello, {{ name }}" | jiren -- --name=world
hello, world

Read a template from a file:

$ echo "hello, {{ name }}" > template.jinja
$ jiren template.jinja -- --name=world
hello, world

jiren uses MiniJinja instead of Jinja2, so some Jinja2 template syntax is not supported. See the MiniJinja compatibility documentation for supported syntax and differences.

Nested command-line variables¶

Use dot-separated variable paths after -- to provide nested values:

$ echo "{{ greeting.message }}" | jiren -- --greeting.message=hello
hello

The default --max-depth=1 supports one nested level. For a deeper path, pass the remaining nested value as a JSON string to the deepest available option:

$ echo "{{ user.profile.name }}" | jiren -- --user.profile='{"name":"you"}'
you

Alternatively, set --max-depth to pass each level as a separate option:

$ echo "{{ user.profile.name }}" | jiren --max-depth=2 -- --user.profile.name=you
you

Inspect template variables¶

Pass --help with a template to list the variables it uses:

$ echo "{{ message }}, {{ name }}" | jiren --help -
...

variables:
  --name NAME
  --message MESSAGE

Use jiren --help without a template argument to show general usage without reading standard input. Use - explicitly when help should include variables from a template provided on standard input.

Default values¶

Jinja default filters can provide values when a variable is not supplied:

$ echo "{{ message }}, {{ name | default('world') }}" | jiren -- --message=hello
hello, world

Options¶

--data PATH, -d PATH¶

Load template variables from a JSON or YAML data file.

$ cat <<EOF > data.yaml
greeting:
  message: hello
  name: world
EOF

$ echo "{{ greeting.message }}, {{ greeting.name }}" | jiren --data=data.yaml
hello, world

Values passed after -- override values with the same top-level name from the data file. Each scalar override is a string, even when the original data value has another type.

--data-string DATA¶

Load template variables from JSON or YAML supplied directly on the command line. This is useful for values that must retain their types without creating a data file.

$ echo "{{ count + 1 }}, {{ enabled | lower }}" | jiren --data-string='{"count": 42, "enabled": true}'
43, true

--data-string cannot be combined with --data.

--max-depth DEPTH¶

Set the maximum nesting depth for command-line variable paths. The default is 1; values beyond that depth are passed as JSON strings.

--strict¶

With --data, report top-level data-file keys that are not used by the template.

$ cat <<EOF > data.yaml
message: hello
invalid_key: invalid
EOF

$ echo "{{ message }}" | jiren --data=data.yaml --strict
jiren: error: the data file contains unknown variables: invalid_key

--required¶

Require a value for every variable used by the template.

$ echo "{{ message }}, {{ name }}" | jiren --required -- --message=hello
jiren: error: the following variables are required: name

--required checks whether every template variable was provided, even when the template uses a Jinja default filter for that variable.

--debug¶

Enable debug log output.

--version, -V¶

Print the installed jiren version and exit.