Parsing commands

The most flexible way to use jQuery Terminal is to use function as interpreter (first argument) and do all the parsing yourself.

$('body').terminal(function(command) {
   // your own parser, the command is everything
   // that users types into terminal and press enter
});

With this, you can use any parser that is out there. Most common languages have their implementation in JavaScript. Example languages can be found in In The wild section of Examples.

The rest of the article shows how to parse commands like those in Linux command line or any other Unix shell. If you're using a function as an interpreter, you can parse the commands to split the command into arguments.

There are two pairs of functions:

• $.terminal.split_arguments
• $.terminal.parse_arguments

and

• $.terminal.split_command
• $.terminal.parse_command

x_command will create an object from a parsed string

{name, args, rest, command, args_quotes}

• name - text before the first space
• args - the array of arguments parsed with x_arguments
• rest - the rest of the text without name and space as is
• command - the input string as is
• args_quotes - an array of strings with a quote used ' or "

x_arguments functions will create an array from the arguments splitted on space. x_command functions use x_arguments functions to process the arguments array.

The processing can handle spaces inside regular expressions and strings.

Another function was added in version 1.17.0: $.terminal.parse_options. It parses the arguments and accepts two parameters either a string or an array and an object with options. Right now, there is only one option available which is boolean. It should be an array of strings, to indicate options that don't have an argument.

parse_options is very simple and is very similar to yargs parser. It returns an object with a field _as an array for the "free" options and each said "free" options is saved as a key with value set to true. The other options appear as key with their value as string:

$.terminal.parse_options(["-x", "foo", "-aby", "bar"], {boolean: ['y']});

this will return

{_: ["bar"], x: "foo", y: true, a: true, b: true}

If you're using an object as interpreter, you can use the following ES5 syntax to get an options array:

$(function() {
    $('#terminal').terminal({
        fetch: function() {
            var args = Array.from(arguments);
            var options = $.terminal.parse_options(args);
            if (!options.url) {
                this.error("You need to specify the url");
            } else if (options.method == 'POST') {
                 return fetch(options.url, {method: 'POST'}).then(function(res) {
                    return res.text();
                 });
            } else {
                 return fetch(options.url).then(function(res) {
                    return res.text();
                 });
            }
        }
    }, {checkArity: false});
});

Or the ES6 version, if you like:

$(function() {
    $('#terminal').terminal({
        fetch: function(...args) {
            var options = $.terminal.parse_options(args);
            if (!options.url) {
                this.error("You need to specify the url");
            } else if (options.method == 'POST') {
                 return fetch(options.url, {method: 'POST'}).then(res => res.text());
            } else {
                 return fetch(options.url).then(res => res.text());
            }
        }
    }, {checkArity: false});
});

and you will get these responses for these commands:

fetch --method "POST" - will show error that the URL is not specified
fetch --url https://example.com/file.txt --method POST - will fetch the file using POST
fetch --url https://example.com/file.txt - will fetch the file using GET method

And here is another example of sudo command:

$('body').terminal({
  sudo(command, ...args) {
     const options = $.terminal.parse_options(args, { boolean: ['f', 'r']});
     if (command === 'rm' && options.r && options.f) {
        if (options._.length) {
           const [dir] = options._;
           this.echo(`wipe ${dir}`);
        } else {
           this.error('rm: missing operand');
        }
     }
  }
}, {
  checkArity: false
});

It allow to execute:

> sudo rm -rf
rm: missing operand
> sudo rm -rf /
wipe /

Another usage example of this function can be found in the API reference.