Chapter 20. Client-Side PHP

20.1. Introduction

The same PHP binary built to be executed as a CGI program can be run from the command line. To run a script, pass the script filename as an argument:

% php scan-discussions.php

#!/usr/local/bin/php

You can then run the script just by typing its name on the command line, as long as the file has execute permission.

Command-line PHP scripts almost always use the -q flag, which prevents PHP from printing HTTP response headers at the beginning of its output:

% php -q scan-discussions.php

You can also use this:

#!/usr/local/bin/php -q

Another helpful option on the command line is the -c flag, which lets you specify an alternate php.ini file to load settings from. If your default php.ini file is /usr/local/lib/php.ini, it can be helpful to have a separate configuration file at /usr/local/lib/php-commandline.ini with settings such as max_execution_time = 0; this ensures that your scripts don't quit after 30 seconds. Here's how to use this alternate file:

% php -q -c /usr/local/lib/php-commandline.ini scan-discussions.php

You can also use this :

#!/usr/local/bin/php -q -c /usr/local/lib/php-commandline.ini

if ($GLOBALS['COMMAND_LINE']) {
  print "Database error: ".mysql_error()."\n";
} else {
  print "Database error.<br>";
  error_log(mysql_error());
}

This code not only adjusts the output formatting based on the context it's executing in (\n versus <br>), but also where the information goes. On the command line, it's helpful to the person running the program to see the error message from MySQL, but on the Web, you don't want your users to see potentially sensitive data. Instead, the code outputs a generic error message and stores the details in the server's error log for private review.

The CLI binary accepts a slightly different set of arguments than the CGI binary. It doesn't accept the -q or -C flags because it does what these flags indicate by default. While -q tells the CGI binary not to print headers, the CLI binary never prints headers. Even the header( ) function produces no output under CLI. Similarly, the -C flag tells the CGI binary not to change to the directory of the script being run. The CLI binary never changes to the script directory.

The CLI binary also takes one new argument: -r. When followed by some PHP code without <?php and ?> script tags, the CLI binary runs the code. For example, here's how to print the current time:

% php -r 'print strftime("%c");'

// read from standard in
$input = fgets(STDIN,1024);

// write to standard out
fwrite(STDOUT,$jokebook);

// write to standard error
fwrite(STDERR,$error_code);

if ('cli' == php_sapi_name()) {
  print "Database error: ".mysql_error()."\n";
} else {
  print "Database error.<br>";
  error_log(mysql_error());
}

if (! class_exists('gtk')) {
    dl('php_gtk.dll');
}

On Unix:

if (! class_exists('gtk')) {
    dl('php_gtk.so');
}

If you want the same script to run unaltered on Unix or Windows, you can load the PHP-GTK extension like this:

if (! class_exists('gtk')) {
    dl('php_gtk.'. (((strtoupper(substr(PHP_OS,0,3))) == 'WIN')?'dll':'so'));
}