Tab Autocompletion (autocomplete)

Set definitions for tab-completion in the command line

Description

autocomplete digests a JSON schema and uses that to define the tab- completion rules for suggestions in the interactive command line.

Usage

autocomplete get [ command ] -> <stdout>

autocomplete set command { mxjson }

Flags

• get output all autocompletion schemas
• set define a new autocompletion schema

Detail

Undefining autocomplete

Currently there is no support for undefining an autocompletion rule however you can overwrite existing rules.

Directives

The directives are listed below.

Alias

Value: str (default: empty)

Aliases are used inside FlagValues as a way of pointing one flag to another without duplicating code. eg -v and --version might be the same flag. Or -?, -h and --help. With Alias you can write the definitions for one flag and then point all the synonyms as an alias to that definition.

AllowAny

Value: bool (default: false)

The way autocompletion works in Murex is the suggestion engine looks for matches and if it fines one, it then moves onto the next index in the JSON schema. This means unexpected values typed in the interactive terminal will break the suggestion engine's ability to predict what the next expected parameter should be. Setting AllowAny to true tells the suggestion engine to accept any value as the next parameter thus allowing it to then predict the next parameter afterwards.

This directive isn't usually necessary because such fields are often the last parameter or most parameters can be detectable with a reasonable amount of effort. However AllowAny is often required for more complex command line tools.

AllowMultiple

Value: bool (default: false)

Set to true to enable multiple parameters following the same rules as defined in this index. For example the following will suggest directories on each tab for multiple parameters:

autocomplete set example %[{
    IncDirs: true
    AllowMultiple: true
}]

AnyValue

Deprecated. Please use AllowAny instead.

AutoBranch

Value bool (default: false)

Use this in conjunction with Dynamic. If the return is an array of paths, for example [ "/home/foo", "/home/bar" ] then AutoBranch will return the following patterns in the command line:

» example [tab]
# suggests "/home/"

» example /home/[tab]
# suggests "/home/foo" and "/home/bar"

Please note that AutoBranch's behavior is also dependant on a "shell" config setting, "recursive-enabled":

» config get shell recursive-enabled
true

CacheTTL

Value: int (default: 5)

Dynamic autocompletions (via Dynamic or DynamicDesc) are cached to improve interactivity performance. By default the cache is very small but you can increase that cache or even disable it entirely. Setting this value will define the duration (in seconds) to cache that autocompletion.

If you wish to disable this then set CacheTTL to -1.

This directive needs to live in the very first definition and affects all autocompletes within the rest of the command. For example

autocomplete set foobar %[
    {
        Flags: [ --foo, --bar ]
        CacheTTL: 60
    }
    {
        Dynamic: '{
            a [Monday..Friday]
            sleep 3
        }'
    }
]

Here the days of the week take 3 seconds to show up as autocompletion suggestions the first time and instantly for the next 60 seconds after.

Dynamic

Value: code block as a str (default: empty)

This is a Murex block which returns an array of suggestions.

Code inside that block are executed like a function and the parameters will mirror the same as those parameters entered in the interactive terminal.

Two variables are created for each Dynamic function:

• ISMETHOD: true if the command being autocompleted is going to run as a pipelined method. false if it isn't.

• PREFIX: contains the partial term. For example if you typed hello wor[tab] then $PREFIX would be set to wor for hello's autocompletion.

The expected stdout should be an array (list) of any data type. For example:

[
    "Monday",
    "Tuesday",
    "Wednesday",
    "Thursday",
    "Friday"
]

You can additionally include suggestions if any of the array items exactly matches any of the following strings:

• @IncFiles (read more)
• @IncDirs (read more)
• @IncExePath (read more)
• @IncExeAll (read more)
• @IncManPage (read more)

DynamicDesc

Value: code block as a str (default: empty)

This is very similar to Dynamic except your function should return a map instead of an array. Where each key is the suggestion and the value is a description.

The description will appear either in the hint text or alongside the suggestion - depending on which suggestion "popup" you define (see ListView).

Two variables are created for each Dynamic function:

• ISMETHOD: true if the command being autocompleted is going to run as a pipelined method. false if it isn't.

• PREFIX: contains the partial term. For example if you typed hello wor[tab] then $PREFIX would be set to wor for hello's autocompletion.

The expected stdout should be an object (map) of any data type. The key is the autocompletion suggestion, with the value being the description. For example:

{
    "Monday": "First day of the week",
    "Tuesday": "Second day of the week",
    "Wednesday": "Third day of the week"
    "Thursday": "Forth day of the week",
    "Friday": "Fifth day of the week",
}

DynamicPreview

Value: code block as a str (default: empty)

The DynamicPreview directive is used to populate the [f1] preview screen.

stdout and stderr are passed directly to the preview frame.

ExecCmdline

Value: bool (default: false)

Sometimes you'd want your autocomplete suggestions to aware of the output returned from the commands that preceded it. For example the suggestions for [ (index) will depend entirely on what data is piped into it.

ExecCmdline tells Murex to run the commandline up until the command which your cursor is editing and pipe that output to the stdin of that commands Dynamic or DynamicDesc code block.

This is a dangerous feature to enable so ExecCmdline is only honoured if the commandline is considered "safe". Dynamic / DynamicDesc will still be executed however if the commandline is "unsafe" then your dynamic autocompletion blocks will have no stdin.

Because this is a dangerous feature, your partial commandline will only execute if the following conditions are met:

• the commandline must be one pipeline (eg ; tokens are not allowed)
• the commandline must not have any new line characters
• there must not be any redirection, including named pipes (eg cmd <namedpipe>) and the stdout/stderr switch token (?)
• the commandline doesn't inline any variables ($strings, @arrays) or functions (${subshell}, $[index])
• lastly all commands are whitelisted in "safe-commands" (config get shell safe-commands)

If these criteria are met, the commandline is considered "safe"; if any of those conditions fail then the commandline is considered "unsafe".

Murex will come with a number of sane commands already included in its safe-commands whitelist however you can add or remove them using config

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

Remember that ExecCmdline is designed to be included with either Dynamic or DynamicDesc and those code blocks would need to read from stdin:

autocomplete set "[" %[{
    AnyValue: true
    AllowMultiple: true
    ExecCmdline: true
    Dynamic: '{
        switch ${ get-type stdin } {
            case * {
                <stdin> -> [ 0: ] -> format json -> [ 0 ]
            }

            catch {
                <stdin> -> formap k v { out $k } -> cast str -> append "]"
            }
        }
    }'
}]

FileRegexp

Value: str (default: empty)

When set in conjunction with IncFiles, this directive will filter on files files which match the regexp string. eg to only show ".txt" extensions you can use the following:

autocomplete set notepad.exe %[{
    IncFiles: true
    FileRegexp: (\.txt)
}]

Please note that you may need to double escape any regexp strings: escaping the . match and then also escaping the escape character in JSON. It is recommended you use the mxjson method of quoting using parentheses as this will compile that string into JSON, automatically adding additional escaping where required.

FlagValues

Value: map of arrays (default: empty)

This is a map of the flags with the values being the same array of directive as the top level.

This allows you to nest operations by flags. eg when a flag might accept multiple parameters.

FlagValues takes a map of arrays, eg

autocomplete set example %[{
    Flags: [ add, delete ]
    FlagValues: {
        add: [{
            Flags: [ foo ]
        }]
        delete: [{
            Flags: [ bar ]
        }]
    }
}]

...will provide "foo" as a suggestion to example add, and "bar" as a suggestion to example delete.

Defaults for matched flags

You can set default properties to all matched flags by using * as a FlagValues value. To expand the above example...

autocomplete set example %[{
    Flags: [ add, delete ]
    FlagValues: {
        add: [{
            Flags: [ foo ]
        }]
        delete: [{
            Flags: [ bar ]
        }]
        "*": [{
            IncFiles
        }]
    }
}]

...in this code we are saying not only does "add" support "foo" and "delete" supports "bar", but both "add" and "delete" also supports any filesystem files.

This default only applies if there is a matched Flags or FlagValues.

Defaults for any flags (including unmatched)

If you wanted a default which applied to all FlagValues, even when the flag wasn't matched, then you can use a zero length string (""). For example

autocomplete set example %[{
    Flags: [ add, delete ]
    FlagValues: {
        add: [{
            Flags: [ foo ]
        }],
        delete: [{
            Flags: [ bar ]
        }],
        "": [{
            IncFiles: true
        }]
    }
}]

Flags

Value: array of strings (default is auto-populated from man pages)

Setting Flags is the fastest and easiest way to populate suggestions because it is just an array of strings. eg

autocomplete set example %[{
    Flags: [ foo, bar ]
}]

If a command doesn't Flags already defined when you request a completion suggestion but that command does have a man page, then Flags will be automatically populated with any flags identified from an a quick parse of the man page. However because man pages are written to be human readable rather than machine parsable, there may not be a 100% success rate with the automatic man page parsing.

FlagsDesc

Value: map of strings (default: empty)

This is the same concept as Flags except it is a map with the suggestion as a key and description as a value. This distinction is the same as the difference between Dynamic and DynamicDesc.

Please note that currently man page parsing cannot provide a description so only Flags get auto-populated.

Goto

Value: str (default: empty)

This is a goto in programming terms. While "ugly" it does allow for quick and easy structural definitions without resorting to writing the entire autocomplete in code.

Goto takes a string which represents the path to jump to from the top level of that autocomplete definition. The path should look something like: /int/string/int/string.... where

• the first character is the separator,

• the first value is an integer that relates to the index in your autocomplete array,

• the second value is a string which points to the flag value map (if you defined FlagValues),

• the third value is the integer of the autocomplete array inside that FlagValues map,

• ...and so on as necessary.

An example of a really simple Goto:

autocomplete set dd %[
    {
        Flags: [ "if=", "of=", "bs=", "iflag=", "oflag=", "count=", "status=" ]
        FlagValues: {
            "if": [{
                IncFiles: true
            }]
            "of": [{
                IncFiles: true
            }]
            "*": [{
                AllowAny: true
            }]
        }
    },
    {
        Goto: "/0"
    }
]

Goto is given precedence over any other directive. So ensure it's the only directive in it's group.

IgnorePrefix

Value: bool (default: false)

When set to true, this allows Dynamic and DynamicDesc functions to return every result and not just those that match the partial term (as would normally be the default).

ImportCompletion

Value: str (default: empty)

This allows you to import autocompletion config from another command. Similar in purpose to NestedCommand except where NestedCommand will dynamically select the command name, ImportCompletion hardcodes it. For example:

autocomplete set murex-package %[{
    FlagsDesc: {
        # ...cropped out...
        git: "Run `git` against a package"
    }
    FlagValues: {
        # ...cropped out...
        git: [
            {
                # list packages to run `git` against
                Dynamic: %({ murex-package list packages })
            }
            {
                # include `git` autocompletions as the next set of parameters
                ImportCompletion: git
            }
        ]
    }
}]

The above code allows you to type murex-package git package-name [tab], where [tab] will be the completions for git.

IncDirs

Value: bool (default: false)

Enable to include directories.

Not needed if IncFiles is set to true.

Behavior of this directive can be altered with config set shell recursive-enabled

IncExeAll

Value: bool (default: false)

Enable this to any executables. Suggestions will include aliases, functions builtins and any executables in $PATH. It will not include private functions.

IncExePath

Value: bool (default: false)

Enable this to include any executables in $PATH. Suggestions will not include aliases, functions nor privates.

IncFiles

Value: bool (default: true)

Include files and directories. This is enabled by default for any commands that don't have autocomplete defined but you will need to manually enable it in any autocomplete schemas you create and want files as part of the suggestions.

If you want to filter files based on file name then you can set a regexp string to match to using FileRegexp.

IncManPage

Value: bool (default: false)

The default behavior for commands with no autocomplete defined is to parse the man page and use those results. If a custom autocomplete is defined then that man page parser is disabled by default. You can re-enable it and include its results with other flags and behaviors you define by using this directive.

ListView

Value: bool (default: false)

This alters the appearance of the autocompletion suggestions "popup". Rather than suggestions being in a grid layout (with descriptions overwriting the hint text) the suggestions are in a list view with the descriptions next to them on the same row (similar to how an IDE might display it's suggestions).

NestedCommand

Value: bool (default: false)

Only enable this if the command you are autocompleting is a nested parameter of the parent command you have types. For example with sudo, once you've typed the command name you wish to elivate, then you would want suggestions for that command rather than for sudo itself.

Optional

Value: bool (default: false)

Specifies if a match is required for the index in this schema. ie optional flags.

Synonyms

• autocomplete

See Also

• Alias Pointer (alias): Create an alias for a command
• Get Data Type (get-type): Returns the data-type of a variable or pipe
• Get Item ([ Index ]): Outputs an element from an array, map or table
• Private Function (private): Define a private function block
• Public Function (function): Define a function block
• Read From Stdin (<stdin>): Read the stdin belonging to the parent code block
• Set Command Summary Hint (summary): Defines a summary help text for a command
• Shell Configuration And Settings (config): Query or define Murex runtime settings
• Switch Conditional (switch): Blocks of cascading conditionals
• mxjson: Murex-flavoured JSON (deprecated)

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This document was generated from builtins/core/autocomplete/autocomplete_doc.yaml.