PHP Cookbook

20.9. Program: Command Shell

The command-shell.php program shown in Example 20-1 provides a shell-like prompt to let you execute PHP code interactively. It reads in lines using readline( ) and then runs them with eval( ). By default, it runs each line after it’s typed in. In multiline mode (specified with -m or --multiline), however, it keeps reading lines until you enter . on a line by itself; it then runs the accumulated code.

Additionally, command-shell.php uses the Readline word-completion features to more easily enter PHP functions. Enter a few characters and hit Tab to see a list of functions that match the characters you’ve typed.

This program is helpful for running snippets of code interactively or testing different commands. The variables, functions, and classes defined in each line of code stay defined until you quit the program, so you can test different database queries, for example:

% php -q command-shell.php
[1]> require 'DB.php';

[2]> $dbh = DB::connect('mysql://user:pwd@localhost/phpc');

[3]> print_r($dbh->getAssoc('SELECT sign,planet,start_day FROM zodiac WHERE element 
            LIKE "water"'));
Array
(
    [Cancer] => Array
        (
            [0] => Moon
            [1] => 22
        )
    [Scorpio] => Array
        (
            [0] => Mars
            [1] => 24
        )
    [Pisces] => Array
        (
            [0] => Neptune
            [1] => 19
        )
)

The code for command-shell.php is in Example 20-1.

Example 20-1. command-shell.php

// Load the readline library if (! function_exists('readline')) { dl('readline.'. (((strtoupper(substr(PHP_OS,0,3))) == 'WIN')?'dll':'so')) or die("Readline ...