10:32 > php -h
Usage: php [options] [-f] <file> [args...]
       php [options] -r <code> [args...]
       php [options] [-- args...]
  -a               Run interactively
  -c <path>|<file> Look for php.ini file in this directory
  -n               No php.ini file will be used
  -d foo[=bar]     Define INI entry foo with value 'bar'
  -e               Generate extended information for debugger/profiler
  -f <file>        Parse <file>.
  -h               This help
  -i               PHP information
  -l               Syntax check only (lint)
  -m               Show compiled in modules
  -r <code>        Run PHP <code> without using script tags <?..?>
  -s               Display colour syntax highlighted source.
  -v               Version number
  -w               Display source with stripped comments and whitespace.
  -z <file>        Load Zend extension <file>.

  args...          Arguments passed to script. Use -- args when first argument 
                   starts with - or script is read from stdin

#!/usr/bin/php 
 <?php
 echo "Hello World\n";

10:35 > php -r 'for($i = 1; $i < 7; $i++) { echo "$i^2: ", ($i*$i),  "\n"; }'
1^2: 1
2^2: 4
3^2: 9
4^2: 16
5^2: 25
6^2: 36