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.

Usage

List all settings:

config -> <stdout>

Get a setting:

config get app key -> `<stdout>`

Set a setting:

config set app key value

`<stdin>` -> config set app key

config eval app key { -> code-block }

Define a new config setting:

config define app key { mxjson }

Reset a setting to it's default value:

!config app key

config default app key

Examples

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

» function: foobar { -> match foobar }
» config: eval shell safe-commands { -> append foobar }

Detail

With regards to config, the following terms are applied:

"app"

This refers to a grouped category of settings. For example the name of a built in.

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"

This 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

"scope" / "scoped"

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.

Please note that config settings are scoped differently to local variables.

"global"

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

Directives

The directives for config define are listed below. Headings are formatted as follows:

"DirectiveName": json data-type (default value)

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": string (required)

This is the Murex data-type for the value.

"Description": string (required)

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

"Global": boolean (false)

This defines whether this setting is global or scoped.

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

"Default": any (required)

This is the initialized and default value.

"Options": array (nil)

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

"Dynamic": map of strings (nil)

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
(this is the default value) -> > example.conf

# mxjson format, so we can have comments and block quotes: #, (, )
config define example test ({
    "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.

See the mxjson data-type for more details.

"Dynamic":

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

"Dynamic":

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

• [[ (element): Outputs an element from a nested structure
• [ (index): Outputs an element from an array, map or table
• append: Add data to the end of an array
• event: Event driven programming for shell scripts
• function: Define a function block
• get: Makes a standard HTTP request and returns the result as a JSON object
• getfile: Makes a standard HTTP request and return the contents as Murex-aware data type for passing along Murex pipelines.
• match: Match an exact value in an array
• open: Open a file with a preferred handler
• post: HTTP POST request with a JSON-parsable return
• runtime: Returns runtime information on the internal state of Murex
• mxjson: Murex-flavoured JSON (deprecated)