config.md

Shell Configuration And Settings (config)

Query or define Murex runtime settings

Description

Rather than Murex runtime settings being definable via obscure environmental variables, Murex instead supports a registry of config defined via the config command. This means any preferences and/or runtime config becomes centralised and discoverable.

Terminology

The following terms have special means with regards to config:

app

app refers to a grouped category of settings. For example the name of an integration or builtin.

Other app names include

• shell: for "global" (system wide) Murex settings
• proc: for scoped Murex settings
• http: for settings that are applied to any processes which use the builtin HTTP user agent (eg open, get, getfile, post)
• test: settings for Murex's test frameworks
• index: settings for [ (index)

key

key refers to the config setting itself. For example the app might be http but the key might be timeout - where the key, in this instance, holds the value for how long any HTTP user agents might wait before timing out.

value

value is the actual value of a setting. So the value for app: http, key: timeout might be 10. eg

» config get http timeout
10

Usage

Get value

config get app key -> <stdout>

Set value

           config set  app key value
<stdin> -> config set  app key
           config eval app key { code-block }

Reset to default

!config app key
config default app key

Define custom configs

config define app key { json }

Examples

eval

Using eval to append to an array (in this instance, adding a function name to the list of "safe" commands):

» config eval shell safe-commands { -> append function-name }

You could also use the ~> operator too:

» config eval shell safe-commands { ~> %[function-name] }

Flags

• default Reset a the value of app's key to its default value (the default value is defined by the same process that defines the config field)
• define Allows you to create custom config options. See Custom Config Directives to learn how to use define
• get Output the currently held config value without changing it
• set Change the value of an app's key. set does not print any output

Detail

scope

Settings in config, by default, are scoped per function and module. Any functions called will inherit the settings of it's caller parent. However any child functions that then change the settings will only change settings for it's own function and not the parent caller.

global

Global settings defined inside a function will affect settings queried inside another executing function (same concept as global variables).

Custom Config Directives

This section relates to creating custom configs via config define. You do not need to refer to this for any regular usage of config.

• DataType
• Description
• Global
• Default
• Options
• Dynamic
  • Dynamic Read
  • Dynamic Write

Where "default value" is what will be auto-populated if you don't include that directive (or "required" if the directive must be included).

DataType

Value: str (required)

This is the Murex data-type for the value.

Description

Value: str (required)

Description is a required field to force developers into writing meaning hints enabling the discoverability of settings within Murex.

Global

Value: bool (default: false)

This defines whether this setting is global or scoped.

All Dynamic config must also be Global. This is because Dynamic config rely on a state that likely isn't scoped (eg the contents of a file on disk or environmental variable).

Default

Value: any (required)

This is the initialized and default value.

Options

Value: array (default: null)

Some suggested options (if known) to provide as autocompletion suggestions in the interactive command line.

Dynamic

Value: map of strings (default: null)

Only use this if config options need to be more than just static values stored inside Murex's runtime. Using Dynamic means autocomplete get app key and autocomplete set app key value will spawn off a subshell running a code block defined from the Read and Write mapped values. eg

# Create the example config file
out "this is the default value" |> example.conf

config define example test5 %{
    Description: This is only an example
    DataType: str
    Global: true
    Dynamic: {
        Read: '{
            open example.conf
        }'
        Write: '{
            |> example.conf
        }'
    },
    
    # read the config file to get the default value
    Default: ${open example.conf}
}

It's also worth noting the different syntax between Read and Default. The Read code block is being executed when the Read directive is being requested, whereas the Default code block is being executed when the JSON is being read.

In technical terms, the Default code block is being executed by Murex when config define is getting executed where as the Read and Write code blocks are getting stored as a JSON string and then executed only when those hooks are getting triggered.

Dynamic Read

Value: str (default: empty)

This is executed when autocomplete get app key is ran. The stdout of the code block is the setting's value.

Dynamic Write

Value: str (default: empty)

This is executed when autocomplete is setting a value (eg set, default, eval). is ran. The stdin of the code block is the new value.

Synonyms

• config
• !config

See Also

• Alter Data Structure (alter / ~>): Change a value within a structured data-type and pass that change along the pipeline without altering the original source input
• Append To List (append): Add data to the end of an array
• Download File (getfile): Makes a standard HTTP request and return the contents as Murex-aware data type for passing along Murex pipelines.
• Get Item ([ Index ]): Outputs an element from an array, map or table
• Get Nested Element ([[ Element ]]): Outputs an element from a nested structure
• Get Request (get): Makes a standard HTTP request and returns the result as a JSON object
• Match String (match): Match an exact value in an array
• Murex Event Subsystem (event): Event driven programming for shell scripts
• Open File (open): Open a file with a preferred handler
• Post Request (post): HTTP POST request with a JSON-parsable return
• Public Function (function): Define a function block
• Shell Runtime (runtime): Returns runtime information on the internal state of Murex
• %{} Object Builder: Quickly generate objects (dictionaries / maps)

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This document was generated from builtins/core/config/config_doc.yaml.