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(’/\n\r*$/’, $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: %s\n”);
$options = Console_Getopt::getopt($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 $i\n”;
close($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, “$u\n”);
}
} else {
$msg = ‘[’.$usernames[$i].’]: ‘.$line.”\n”;
broadcast($msg, $i);
output($i, “>>> $line\n”);
}
}
}
foreach ($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 $i\n”;
$may_shutdown = false;
break;
}
}
if ($may_shutdown) {
print “shutdown complete\n”;
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) . “\r\n”;
}
$output[$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.