CHAPTER 16 – Parsing Command-Line Options – Examples

Here are some examples of command-line tools written in PHP.

PHP Filter Utility This example includes a little tool for filtering line by line from standard input through a PHP function that returns a string: #!/usr/bin/env php <?php if (empty($argv[1])) { die("Usage: phpfilter <function>n"); } $function = $argv[1]; while ($line = fgets(STDIN)) { $out = $function($line); if (!preg_match('/nr*$/', $out)) { $out .= "n"; } print $out; }

phpfilter This example reads line by line from STDIN, which is a pre- defined file resource in PHP for standard input. An extra newline is added in case the PHP function stripped away the newline. Try it with base64_encode: $ ls | phpfilter base64_encode QnVpbGRpbmdfUEVBUl9Db21wb25lbnRzLwkJICAgUGVyZm9ybWFuY2UvCg== Q2hhcHRlciAxMyAtIEJ1aWxkaW5nIFBFQVIgQ29tcG9uZW50cy56aXAgIHJldmlld3Mv g== RGF0YWJhc2VzLwkJCQkgICBTaGVsbF9TY3JpcHRpbmcvCg== RXJyb3JfSGFuZGxpbmcvCQkJCSAgIHRtcC8K SW1wb3J0YW50X1BFQVJfUGFja2FnZXMvCQkgICBVc2luZ19QRUFSLwo= The final example is a simple chat server. It handles many simultaneous users, does buffering of input and output, may run as a daemon, and has three commands: /who, /quit, and /shutdown. Connect to it with a telnet program; it uses port 1234 by default. To log out, type /quit; to see what users are on type /who; type /shutdown to take the server down. You may change the port number with the ­p option, or the maximum number of simultaneous users with the ­m option. Try the ­h option for help: <?php error_reporting(E_ALL); require_once "PEAR.php"; require_once "Console/Getopt.php"; $DAEMON = false; $PORT = 1234; $MAX_USERS = 50; $progname = basename($argv[0]); PEAR::setErrorHandling(PEAR_ERROR_DIE, "$progname: %sn"); $options = Console_Getopt::getopt($argv, "dp:m:h"); foreach ($options[0] as $opt) { switch ($opt[0]) { case 'd': $DAEMON = true; break; case 'p': $PORT = $opt[1]; break; case 'm': $MAX_USERS = $opt[1]; break; case 'h': case '?': fwrite(STDERR, "Usage: $progname [-dh] [-p port] [-m users] Options: -d detach into background (daemon mode) -p port set tcp port number -m users set max number of users -h this help message "); exit(1); } } if ($DAEMON) { $pid = pcntl_fork(); if ($pid) { exit(0); } posix_setsid(); } $sock = socket_create_listen($PORT); if (!$sock) { exit(1); } $shutting_down = false; $connections = array(); $usernames = array(); $input = array(); $output = array(); $close = array(); while (true) { $readfds = array_merge($connections, array($sock)); $writefds = array(); reset($output); while (list($i, $b) = each($output)) { if (strlen($b) > 0) { $writefds[] = $connections[$i]; } } if (socket_select($readfds, $writefds, $e = null, 60)) { foreach ($readfds as $rfd) { if ($rfd == $sock) { $newconn = socket_accept($sock); $i = (int)$newconn; $reject = ''; if (count($connections) >= $MAX_USERS) { $reject = "Server full. Try again later.n"; } elseif ($shutting_down) { $reject = "Server shutting down.n"; } $connections[$i] = $newconn; $output[$i] = ''; if ($reject) { output($i, $reject); $close[$i] = true; } else { output($i, "Welcome to the PHP Chat Server!n"); output($i, "Username: "); } $usernames[$i] = ""; $input[$i] = ""; continue; } $i = (int)$rfd; $tmp = @socket_read($rfd, 2048, PHP_NORMAL_READ); if (!$tmp) { broadcast($usernames[$i] . " lost link.n"); print "connection closed on socket $in"; close($i); continue 2; } $input[$i] .= $tmp; $tmp = substr($input[$i], -1); if ($tmp != "r" && $tmp != "n") { // no end of line, more data coming continue; } $line = trim($input[$i]); $input[$i] = ""; if (empty($line)) { continue; } if (empty($usernames[$i])) { if (strlen($line) < 2) { output($i, "Username must be at least two characters.n"); } else { $user = substr($line, 0, 16); $f = array_search($user, $usernames); if ($f !== false) { output($i, "That user name is taken, try another.n"); } else { $usernames[$i] = $user; output($i, "You are now known as "$user".n"); broadcast("$user has logged on.n", $i); continue; } } } if (empty($usernames[$i])) { output($i, "Username: "); } else { if (strtolower($line) == "/quit") { output($i, "Bye!n"); broadcast("$usernames[$i] has logged off.", $i); $close[$i] = true; } elseif (strtolower($line) == "/shutdown") { $shutting_down = true; broadcast("Shutting down. See you later.n"); } elseif (strtolower($line) == "/who") { output($i, "Current users:n"); foreach ($usernames as $u) { output($i, "$un"); } } else { $msg = '['.$usernames[$i].']: '.$line."n"; broadcast($msg, $i); output($i, ">>> $linen"); } } } foreach ($writefds as $wfd) { $i = (int)$wfd; if (!empty($output[$i])) { $w = socket_write($wfd, $output[$i]); if ($w == strlen($output[$i])) { $output[$i] = ""; if (isset($close[$i])) { close($i); } } else { $output[$i] = substr($output[$i], $w); } } } } if ($shutting_down) { $may_shutdown = true; foreach ($output as $i => $o) { if (strlen($o) > 0) { print "shutdown: still data on fd $in"; $may_shutdown = false; break; } } if ($may_shutdown) { print "shutdown completen"; socket_shutdown($sock); socket_close($sock); exit; } } } function output($user, $msg) { global $output; settype($user, "int"); $tmp = substr($msg, -2); if ($tmp{1} == "n" && $tmp{0} != "r") { $msg = substr($msg, 0, -1) . "rn"; } $output[$user] .= $msg; } function broadcast($msg, $except = null) { global $output, $connections, $usernames; foreach ($connections as $i => $r) { if (empty($usernames[$i])) { // don't send messages to users who have not logged on yet continue; } if (!$except || $except != $i) { output($i, $msg); } } } function close($i) { global $connections, $input, $output, $usernames, $close; socket_shutdown($connections[$i]); socket_close($connections[$i]); unset($connections[$i]); unset($input[$i]); unset($output[$i]); unset($usernames[$i]); unset($close[$i]); } ?>

SUMMARY In this chapter, you went beyond the web environment and learned how to use PHP for command-line shell scripting. Although Perl and shell scripts are the dominant players in this arena, writing PHP scripts allows you to re-use PHP and PEAR library code for offline maintenance tools. You have learned about Parsing command-line options using PEAR Console_Getopt Good shell script behavior Dealing with standard input/output Process control Writing PHP servers Hopefully, this is a powerful supplement to your PHP toolbox.