murex Shell Docs

Command Reference: alter

Change a value within a structured data-type and pass that change along the pipeline without altering the original source input

Description

alter a value within a structured data-type.

The path separater is defined by the first character in the path. For example /path/to/key, ,path,to,key, |path|to|key and #path#to#key are all valid however you should remember to quote or escape any special characters (tokens) used by the shell (such as pipe, |, and hash, #).

The value must always be supplied as JSON however

Usage

<stdin> -> alter: [ -m | --merge ] /path value -> <stdout>

Examples

» config: -> [ shell ] -> [ prompt ] -> alter: /Value moo
{
    "Data-Type": "block",
    "Default": "{ out 'murex » ' }",
    "Description": "Interactive shell prompt.",
    "Value": "moo"
}

alter also accepts JSON as a parameter for adding structured data:

config: -> [ shell ] -> [ prompt ] -> alter: /Example { "Foo": "Bar" }
{
    "Data-Type": "block",
    "Default": "{ out 'murex » ' }",
    "Description": "Interactive shell prompt.",
    "Example": {
        "Foo": "Bar"
    },
    "Value": "{ out 'murex » ' }"
}

However it is also data type aware so if they key you're updating holds a string (for example) then the JSON data a will be stored as a string:

» config: -> [ shell ] -> [ prompt ] -> alter: /Value { "Foo": "Bar" }
{
    "Data-Type": "block",
    "Default": "{ out 'murex » ' }",
    "Description": "Interactive shell prompt.",
    "Value": "{ \"Foo\": \"Bar\" }"
}

Numbers will also follow the same transparent conversion treatment:

» tout: json { "one": 1, "two": 2 } -> alter: /two "3"
{
    "one": 1,
    "two": 3
}

Please note: alter is not changing the value held inside config but instead took the STDOUT from config, altered a value and then passed that new complete structure through it's STDOUT.

If you require modifying a structure inside murex config (such as http headers) then you can use config alter. Read the config docs for reference.

-m / --merge

Thus far all the examples have be changing existing keys. However you can also alter a structure by appending to an array or a merging two maps together. You do this with the --merge (or -m) flag.

» out: a\nb\nc -> alter: --merge / ([ "d", "e", "f" ])
a
b
c
d
e
f

Detail

Path

The path parameter can take any character as node separators. The separator is assigned via the first character in the path. For example

config -> alter: .shell.prompt.Value moo
config -> alter: >shell>prompt>Value moo

Just make sure you quote or escape any characters used as shell tokens. eg

config -> alter: '#shell#prompt#Value' moo
config -> alter: ' shell prompt Value' moo

Supported data-types

The value field must always be supplied as JSON however the STDIN struct can be any data-type supported by murex.

You can check what data-types are available via the runtime command:

runtime --marshallers

Marshallers are enabled at compile time from the builtins/data-types directory.

See Also

This site's content is rebuilt automatically from murex's source code after each merge to the master branch. Downloadable murex binaries are also built with the website.

Last built on Tue Jun 22 08:18:17 UTC 2021 against commit 2235c7b2235c7b18f86f1cf214e246b88b0ea193d87fe80.

Current version is 2.2.1100 BETA which has been verified against tests.