Using the command line

CasperJS ships with a built-in command line parser on top of PhantomJS’ parser, located in the cli module. It exposes passed arguments as positional ones and named options

A Casper instance always contains a ready-to-use cli property for easy access to these parameters, so you don’t have to worry about manipulating the cli module parsing API.

Let’s consider this simple casper script:

var casper = require("casper").create();

casper.echo("Casper CLI passed args:");
require("utils").dump(casper.cli.args);

casper.echo("Casper CLI passed options:");
require("utils").dump(casper.cli.options);

casper.exit();

Note

Please note the two casper-path and cli options; these are passed to the casper script through the casperjs Python executable.

Execution results:

$ casperjs test.js arg1 arg2 arg3 --foo=bar --plop anotherarg
Casper CLI passed args: [
    "arg1",
    "arg2",
    "arg3",
    "anotherarg"
]
Casper CLI passed options: {
    "casper-path": "/Users/niko/Sites/casperjs",
    "cli": true,
    "foo": "bar",
    "plop": true
}

Getting, checking or dropping parameters:

var casper = require("casper").create();
casper.echo(casper.cli.has(0));
casper.echo(casper.cli.get(0));
casper.echo(casper.cli.has(3));
casper.echo(casper.cli.get(3));
casper.echo(casper.cli.has("foo"));
casper.echo(casper.cli.get("foo"));
casper.cli.drop("foo");
casper.echo(casper.cli.has("foo"));
casper.echo(casper.cli.get("foo"));
casper.exit();

Execution results:

$ casperjs test.js arg1 arg2 arg3 --foo=bar --plop anotherarg
true
arg1
true
anotherarg
true
bar
false
undefined

Hint

You may need to wrap an option containing a space with escaped double quotes in Windows. –foo=\”space bar\”

Hint

What if you want to check if any arg or option has been passed to your script? Here you go:

// removing default options passed by the Python executable
casper.cli.drop("cli");
casper.cli.drop("casper-path");

if (casper.cli.args.length === 0 && Object.keys(casper.cli.options).length === 0) {
    casper.echo("No arg nor option passed").exit();
}

casperjs native options

New in version 1.1.

The casperjs command has three available options:

  • --direct: to print out log messages to the console
  • --log-level=[debug|info|warning|error] to set the logging level
  • --engine=[phantomjs|slimerjs] to select the browser engine you want to use. CasperJS supports PhantomJS (default) that runs Webkit, and SlimerJS that runs Gecko.

Warning

Deprecated since version 1.1.

The --direct option has been renamed to --verbose. Although --direct will still work, it is now considered deprecated.

Example:

$ casperjs --verbose --log-level=debug myscript.js

Last but not least, you can still use all PhantomJS standard CLI options as you would do with any other PhantomJS script:

$ casperjs --web-security=no --cookies-file=/tmp/mycookies.txt myscript.js

Hint

To remember what the native PhantomJS cli options are available, run the phantomjs --help command. SlimerJS supports almost same options as PhantomJS.

Raw parameter values

New in version 1.0.

By default, the cli object will process every passed argument & cast them to the appropriate detected type; example script:

var casper = require('casper').create();
var utils = require('utils');

utils.dump(casper.cli.get('foo'));

casper.exit();

If you run this script:

$ casperjs c.js --foo=01234567
1234567

As you can see, the 01234567 value has been cast to a Number.

If you want the original string, use the raw property of the cli object, which contains the raw values of the passed parameters:

var casper = require('casper').create();
var utils = require('utils');

utils.dump(casper.cli.get('foo'));
utils.dump(casper.cli.raw.get('foo'));

casper.exit();

Sample usage:

$ casperjs c.js --foo=01234567
1234567
"01234567"

For very long numbers, use the raw property as there is an ECMA script limitation with a numeric precision of up to 17 places. More info here - https://github.com/casperjs/casperjs/issues/1134