jiren

jiren is an application that generates text from a template. The format of the template is based on jinja2.

Installation

$ pip install jiren

Usage

Generate text

Generate text from a template using the jiren command. This command can read a template from stdin or files.

An example of reading a template from stdin:

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

An example of reading a template from a file:

$ echo "hello, {{ name }}" >template.j2
$ jiren template.j2 -- --name=world
hello, world

In this example, the template contains a variable called name. You can set values for variables in a template using program arguments passed to the jiren command. Note that the arguments for the variables must be located after --.

If you want to know more about template format, please refer to jinja2 document ( http://jinja.pocoo.org/ ).

Variables in a template

You can use the help to check the variables defined in a template.

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

variables:
  --name NAME
  --message MESSAGE

Default values

You can set default values for variables for which no values was specified. This is based on the jinja2 specification.

Command:

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

Outputs:

hello, world

Option: data

You can pass a file with variables defined structurally using the --data option.

Command:

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

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

Outputs:

hello, world

Option: strict

If the --strict option is used with the --data option, all variables in the data file must be used in the template.

Command:

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

echo "{{ message }}" | jiren --data=data.yaml --strict -

Outputs:

jiren: error: the data file contains unknown variables: invalid_key

Option: required

When using the --required option, you must specify values for all variables.

Command:

echo "{{ message }}, {{ name }}" | jiren --required - -- --message=hello

Outputs:

jiren: error: the following variables are required: name