The Elk Shell Language

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Shell Customisation ​

Init File ​

Elk looks for the init file in ~/.config/elk/init.elk, and runs it when starting a new shell session if it exists. The init file can be compared to the .bashrc file used in bash.

Custom Prompt ​

Elk generates the prompt by calling a function called elkPrompt. This function can be re-defined in the init file in order to customise the prompt. The value returned by the function is used as the prompt. The default implementation of the elkPrompt function can be found in the init file at /usr/share/elk/init.elk

Alias ​

Aliases can be created with the syntax alias name="value" and removed with the syntax unalias name.

elk
alias l="ls --color"
unalias l
alias l="ls --color"
unalias l

Custom Completions ​

The cli module can be used to set up custom completions for the interactive shell. In order to register a file specifying completions for a program, it can be added to the ~/.config/elk/completions directory. The completions will then automatically be loaded when a program with the same name as the file is used. In order for this to work, cli::registerForCompletion needs to be invoked in the file as well. The built-in completions can be found in the repository.

Below is a trimmed down example of the custom completions for git:

elk
# ~/.config/elk/completions/git.elk

cli::create git
    | cli::registerForCompletion
    | cli::addVerb add => &handleAdd
    | cli::addArgument({ "valueKind": "path", "variadic": true })
    | cli::addFlag({ "short": "v", "long": "version", "description": "display git version" })

fn handleAdd(parser) {
    parser
        | cli::addArgument({ "identifier": "file", "completionHandler": &unstagedFilesHandler, "variadic": true })
}

fn unstagedFilesHandler(value, state) {
    let repoPath = git rev-parse --show-toplevel
    git ls-files ${repoPath} --exclude-standard --others --modified | str::path::fuzzyFind(value)
}
# ~/.config/elk/completions/git.elk

cli::create git
    | cli::registerForCompletion
    | cli::addVerb add => &handleAdd
    | cli::addArgument({ "valueKind": "path", "variadic": true })
    | cli::addFlag({ "short": "v", "long": "version", "description": "display git version" })

fn handleAdd(parser) {
    parser
        | cli::addArgument({ "identifier": "file", "completionHandler": &unstagedFilesHandler, "variadic": true })
}

fn unstagedFilesHandler(value, state) {
    let repoPath = git rev-parse --show-toplevel
    git ls-files ${repoPath} --exclude-standard --others --modified | str::path::fuzzyFind(value)
}