# Declaring Getopt Rules

The constructor for the Zend_Console_Getopt class takes from one to three arguments. The first argument declares which options are supported by your application. This class supports alternative syntax forms for declaring the options. See the sections below for the format and usage of these syntax forms.

The constructor takes two more arguments, both of which are optional. The second argument may contain the command-line arguments. This defaults to `$_SERVER['argv']`.

The third argument of the constructor may contain an configuration options to customize the behavior of Zend_Console_Getopt. See Adding Configuration for reference on the options available.

## Declaring Options with the Short Syntax

Zend_Console_Getopt supports a compact syntax similar to that used by GNU Getopt (see http://www.gnu.org/software/libc/manual/html_node/Getopt.html. This syntax supports only single-character flags. In a single string, you type each of the letters that correspond to flags supported by your application. A letter followed by a colon character (:) indicates a flag that requires a parameter.

Using the Short Syntax

    $opts = new Zend_Console_Getopt('abp:');

The example above shows using Zend_Console_Getopt to declare that options may be given as `-a`, `-b`, or `-p`. The latter flag requires a parameter.

The short syntax is limited to flags of a single character. Aliases, parameter types, and help strings are not supported in the short syntax.

## Declaring Options with the Long Syntax

A different syntax with more features is also available. This syntax allows you to specify aliases for flags, types of option parameters, and also help strings to describe usage to the user. Instead of the single string used in the short syntax to declare the options, the long syntax uses an associative array as the first argument to the constructor.

The key of each element of the associative array is a string with a format that names the flag, with any aliases, separated by the pipe symbol ("|"). Following this series of flag aliases, if the option requires a parameter, is an equals symbol ("=") with a letter that stands for the type of the parameter:

- "=s" for a string parameter

- "=w" for a word parameter (a string containing no whitespace)

- "=i" for an integer parameter

If the parameter is optional, use a dash ("-") instead of the equals symbol.

The value of each element in the associative array is a help string to describe to a user how to use your program.

Using the Long Syntax

    $opts = new Zend_Console_Getopt(
      array(
        'apple|a'    => 'apple option, with no parameter',
        'banana|b=i' => 'banana option, with required integer parameter',
        'pear|p-s'   => 'pear option, with optional string parameter'
      )
    );

In the example declaration above, there are three options. `--apple` and `-a` are aliases for each other, and the option takes no parameter. `--banana` and `-b` are aliases for each other, and the option takes a mandatory integer parameter. Finally, `--pear` and `-p` are aliases for each other, and the option may take an optional string parameter.