2. Jeroen Keppens
• Amazium bvba
• Team Leader
• Scrum Master
• Senior PHP Developer
• @jkeppens
• blog.amazium.com

3. Download code examples
http://www.amazium.com/
phpinthedark.tgz

4. shell scripting
photo : istockphoto

5. php-cli
• server api (sapi)
PHP Extensions
• coordinates php
lifecycle
PHP CORE Zend Engine
request mgmt Compile/Exec
• command line interface network & file i/o Memory alloc
• shebang
SAPI (Server API)
http://www.slideshare.net/combell/cli-the-other-sapi-confoo11

6. globals
• no $_POST, $_GET Array (
[TERM_PROGRAM] => Apple_Terminal
[TERM] => xterm-color
• no HTTP_*
[SHELL] => /bin/bash
[TERM_PROGRAM_VERSION] => 273
[USER] => jkeppens
[COMMAND_MODE] => unix2003
• no REMOTE_* [PWD] => /Users/jkeppens
[HOME] => /Users/jkeppens
[LOGNAME] => jkeppens
• no SERVER_* [LC_CTYPE] => UTF-8
[DISPLAY] => /tmp/launch-hr4Dxt/
org.x:0
• term / shell information
[argv] => Array ( [0] => /tmp/
test.php )
[argc] => 1
)
• argv / argc

7. cronjobs
• schedule task ( crontab -u username -e )
* * * * * command to be executed
| | | | |
| | | | +----- day of week (0 - 6) (Sunday=0)
| | | +------- month (1 - 12)
| | +--------- day of month (1 - 31)
| +----------- hour (0 - 23)
+------------- min (0 - 59)
• define constants, access via $_SERVER[‘name’]
NAME = VALUE

8. cronjobs
; define constants
APPLICATION_ENVIRONMENT = development
DB_SERVER = db1.somehost.com
; run every day at 4:30
30 4 * * * /path/to/somescript.php -daily
; run every 5 minutes
*/5 * * * * /path/to/somescript.php
; run every monday and thursday, at midnight and 9AM
* 0,9 * * 1,4 /path/to/somescript

9. input / output
http://www.fotopedia.com/items/flickr-217097889

10. the basics : argc | argv
• $argc = number of
arguments
• $argv = array of
arguments
• first element = script
filename
photo by Kore Nordmann - http://kore-nordmann.de/photos/misc/full/elephpant_39.html

11. the basics : argc | argv
• $argc = number of // Number of arguments
echo '$argc = ';
arguments echo $argc . PHP_EOL;
// Array of arguments
• $argv = array of echo '$argv = ';
print_r($argv);
arguments
• first element = script
filename

12. ./01-basic-input.php -u Jeroen -p test -h -v
Text

13. ./01-basic-input.php -u Jeroen -p test -h -v
$argc = 7
$argv = Array
(
[0] => ./01-basic-input.php
[1] => -u
[2] => Jeroen
[3] => -p Text
[4] => test
[5] => -h
[6] => -v
)

14. getopt ( )
• arguments are parsed
• no validation
• short options
• long options since 5.3
• no, optional or
required values
photo by Martha de Jong-Lantink - http://www.fotopedia.com/wiki/Emperor_Penguin#!/items/flickr-2080338469

15. // Define short options
$short = "hv";
$short.= "u:"; // required
getopt ( )
$short.= "p::"; // optional
// Define long options
$long = array(
"help", "verbose",
• arguments are parsed "user:", // required
"passwd::", // optional
);
• no validation
// Get the options (php 5.3)
• short options $options = getopt(
$shortopts,
$longopts
• long options since 5.3 );
• no, optional or // Show it
print_r($options);
required values

16. ./02-basic-getopt.php -u Jeroen -h -ppasswd

17. ./02-basic-getopt.php -u Jeroen -h -ppasswd
Array
(
[u] => Jeroen
[p] => passwd
[h] =>
)

18. ./02-basic-getopt.php -u Jeroen -h -ppasswd
Array
(
[u] => Jeroen
[p] => passwd
[h] =>
)
./02-basic-getopt.php -u -h -p passwd

19. ./02-basic-getopt.php -u Jeroen -h -ppasswd
Array
(
[u] => Jeroen
[p] => passwd
[h] =>
)
./02-basic-getopt.php -u -h -p passwd
Array
(
[u] => -h
[p] =>
)

20. pear | getopt
• Console_Getopt class
• readPHPArgv ( )
• getopt ( )
• getopt2 ( )
• PEAR Errors
• short / long options unlinked

21. // Define short options
$shortopts = "hv";
$shortopts.= "u:";
$shortopts.= "p::";
pear | getopt
// Define long options
$longopts = array(
"help", "verbose",
"user=",
"password==",
);
• Console_Getopt class
$getopt = new Console_Getopt();
• readPHPArgv ( ) // Get the arguments & remove script
$args = $getopt->readPHPArgv();
• getopt ( ) array_shift($args);
// Parse the options
• getopt2 ( ) $options = $getopt->getopt2(
$args, $shortopts, $longopts);
• PEAR Errors if (PEAR::isError($options)) {
echo 'Got error: ';
• short / long options unlinked echo $options->getMessage();
} else {
print_r($options);
}

22. zend | getopt
• Zend_Console_Getopt
• options linked
• value type validation
• usage message
• object returned
• exceptions
photo : istockphoto

23. // Define short option
$cfg = array(
"help|h" => "Show help",
"verbose|v" => "Verbose mode",
zend | getopt
"user|u=s" => "Username (string)",
"password|p-s"
=> "Password (string) (optional)"
);
try {
$opts = new Zend_Console_Getopt($cfg);
• Zend_Console_Getopt $opts->parse();
if (!empty($opts->help)) {
echo $opts->getUsageMessage();
• options linked } else {
$user = $opts->user;
$passwd = $opts->password;
• value type validation
$verbose = !empty($opts->v);
echo "Log in [$user / $passwd]";
if ($verbose) {
echo " in verbose mode";
• usage message }
}
}
• object returned catch (Zend_Console_Getopt_Exception $e)
{
echo $opts->getUsageMessage();
• exceptions
}

24. ./03-zend-getopt.php -h

25. ./03-zend-getopt.php -h
Usage: ./03-zend-getopt.php [ options ]
--help|-h Show help
--verbose|-v Verbose mode
--user|-u <string> Username (string)
--password|-p [ <string> ] Password (string) (optional)

26. readline
• interactive input
• GNU Readline library
• auto-completion
• command history
• callback functions
photo by Gracey Heart - http://www.flickr.com/photos/graceyheartphotography/5552036368/

27. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

28. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

29. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

30. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

31. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

32. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

33. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

34. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

35. // Autocompletion
function autocomplete() {
return array('history', 'clear', 'cls', 'quit', 'exit');
}
readline_completion_function('autocomplete');
// Initiate history
if (is_file($historyFile)) readline_read_history($historyFile);
while (true) {
$line = strtolower(trim(readline('Command: ')));
echo 'Received [ ' . $line . ' ]' . PHP_EOL;
readline_add_history($line); // add command to history
switch ($line) {
case 'clear': case 'cls':
readline_clear_history(); break;
case 'history':
print_r(readline_list_history()); break;
case 'quit': case 'exit':
break 2;
}
}
readline_write_history($historyFile); // Write back to disk

36. output
helpers
• pear Console_*
• ez consoletools
• text formatting
• progressbars
• tables

37. ncurses
• terminfo format
• padding
• coloring
• windows
• keyboard / mouse input
• alternative: whiptail

38. daemons
photo by PSA Peugeot Citroen - http://bit.ly/peugeot-car-welding

39. steps to create a daemon
• Fork off the parent process

40. steps to create a daemon
• Fork off the parent process
• Change the file mode mask

41. steps to create a daemon
• Fork off the parent process
• Change the file mode mask
• Open any logs for writing

42. steps to create a daemon
• Fork off the parent process
• Change the file mode mask
• Open any logs for writing
• Create a new session id & detach current session

43. steps to create a daemon
• Fork off the parent process
• Change the file mode mask
• Open any logs for writing
• Create a new session id & detach current session
• Change the current working directory

44. steps to create a daemon
• Fork off the parent process
• Change the file mode mask
• Open any logs for writing
• Create a new session id & detach current session
• Change the current working directory
• Close standard file descriptors

45. fork off the parent process
• pcntl_fork ( )
• creates copy of parent
• different pid & ppid
• [pid] : parent process
• 0 : child process
• -1 : error forking
photo by Conan (conanil) - http://www.flickr.com/photos/conanil/1215118030/

46. fork off the parent process
• pcntl_fork ( ) // We fork the script
$pid = pcntl_fork();
• creates copy of parent // We add our daemon &
// child code
• different pid & ppid if ($pid == -1) {
die('Could not fork!');
• [pid] : parent process } elseif ($pid) {
// we are the child
} else {
• 0 : child process // we are the parent
}
• -1 : error forking

47. change the file mode mask
• umask (mask)
• mask: octal notation
• system umask & mask
• revoke permissions
• 0: reset to system mask
• dirs: 0777, files: 0666
photo by The Mad Hatter - http://www.lauraleeburch.com/blog/2010/05/the-mad-hatter-2/

48. change the file mode mask
• umask (mask) // system umask = 0022
touch($testFile);
// resulting permissions:
• mask: octal notation // 0666 - 0022 = 0644
• system umask & mask // remove test file
unlink($testFile);
• revoke permissions // reset umask = 0007
umask(0007);
• 0: reset to system mask touch($testFile);
// resulting permissions:
• dirs: 0777, files: 0666 // 0666 - 0007 = 0660

49. Open any logs for writing
• no feedback via shell
• debug info via logs
• logging via
• database
• logfiles
• syslogd
photo by Miranda Hine - http://www.flickr.com/photos/mirandahine/5500665022

50. Open any logs for writing
• no feedback via shell // open syslog wth processID
openlog('SyslogTest',
LOG_PID | LOG_PERROR,
• debug info via logs LOG_LOCAL0);
• logging via $access = date('H:i:s');
syslog(LOG_WARNING, 'Data
• database was accessed @ ' . $access);
closelog();
• logfiles
// Oct 20 15:36:12 amazium
• syslogd SyslogTest[11785]: Data was
accessed @ 15:36:12

51. Create a new session id
• acquire unique SID
• avoid system orphans
• posix_setsid ( )
• sid on success
• -1 on error
photo by Notch Brewing - http://www.notchsession.com

52. Create a new session id
• acquire unique SID // Forked, client part
// let's detach
• avoid system orphans $sid = posix_setsid();
• posix_setsid ( ) // Die on failure to detach
if ($sid < 0) {
• sid on success die('Could not detach
session id.');
}
• -1 on error

53. Change current working dir
• daemon can be started
from any location
• mounts can disappear
• change cwd to a safe
location
• getcwd ( )
• chdir ( )
photo by Majeq - http://majeq.deviantart.com/art/Broken-Bridge-Speedy-176766406

54. Close standard file descriptors
• STDIN, STDOUT, STDERR
• inherited from parent
• unknown targets
• i.e. output still to shell
• close & reconnect file
descriptors with fclose
& fopen
photo : istockphoto

55. // Log file to write to
$logfile = '/tmp/some-log-file.log';
// Close standard I/O descriptors
fclose(STDIN);
fclose(STDOUT);
fclose(STDERR);
// First 3 descriptors fill up the blanks
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
// STDIN reads from /dev/null
// STDOUT writes to $logfile
// STDERR writes to STDOUT, so also to $logfile

56. $pid = pcntl_fork();
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

57. $pid = pcntl_fork(); fork off the parent process
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

58. $pid = pcntl_fork(); set the user creation mask
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

59. $pid = pcntl_fork(); open any log files
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

60. $pid = pcntl_fork(); detach current session
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

61. $pid = pcntl_fork(); change current working dir
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

62. $pid = pcntl_fork(); close open file descriptors
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

63. $pid = pcntl_fork(); payload
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

64. $pid = pcntl_fork();
if ($pid > 1) {
exit(0);
} elseif ($pid == 0) {
umask(0);
openlog('MyLog', LOG_PID | LOG_PERROR, LOG_LOCAL0);
$sid = posix_setsid();
if ($sid < 0) {
syslog(LOG_ERROR, 'Could not detach session id.');
exit(1);
}
chdir(dirname(__FILE__)); Text
fclose(STDIN); fclose(STDOUT); fclose(STDERR);
$fdIN = fopen('/dev/null', 'r');
$fdOUT = fopen($logfile, 'a');
$fdERR = fopen('php://stdout', 'a');
while (true) { /* ... */ }
closelog();
exit(0);
}

65. garbage collection
• no garbage collection
• since php 5.3:
• gc_enable ( )
• gc_collect_cycles ( )
• clearstatcache ( )
• memory_get_usage ( )
photo by Rob Wallace - http://www.flickr.com/photos/robwallace/129263335

66. pear | System_Daemon
• hide complexity
• start() = fork point
• generate init.d scripts
• More info see:
http://kevin.vanzonneveld.net/techblog/
article/create_daemons_in_php/
photo by Rob Wallace - http://www.flickr.com/photos/robwallace/129263335

67. Text

68. inter-process communication

69. signals
• standard vs real-time
• communication
• alerts
• timers
• signal handling
photo by Majeq - http://majeq.deviantart.com/art/Broken-Bridge-Speedy-176766406

70. signals
• SIGINT - CRTL-C
• SIGTSTP - CTRL-Z
• SIGQUIT - CTRL-
• SIGTERM - kill [pid]
• SIGKILL - kill -9 [pid]
• SIGHUP - kill -hup [pid]
• SIGUSR1 - kill -10 [pid]
photo by Majeq - http://majeq.deviantart.com/art/Broken-Bridge-Speedy-176766406

71. // SIGKILL to self
$pid = posix_getpid();
posix_kill($pid, 9);
signals // SIGUSR1 to process group
$pgrp = posix_getpgrp();
posix_kill($pgrp, SIGUSR1);
• SIGINT - CRTL-C // SIGHUP to nr of processes
$pids = array(/* .. */);
• SIGTSTP - CTRL-Z foreach ($pids as $pid) {
posix_kill($pid, SIGHUP);
• SIGQUIT - CTRL- }
• SIGTERM - kill [pid] // Check process alive
if (posix_kill($aPid, 0)) {
• SIGKILL - kill -9 [pid] echo "$aPid is alive!";
} else {
• SIGHUP - kill -hup [pid] echo "$aPid is dead.";
}
• SIGUSR1 - kill -10 [pid]

72. declare(ticks = 1);
function handler($signal) {
global $doPing;
signals
switch ($signal) {
case SIGTERM: case SIGQUIT:
echo "We’re done!n";
// handle shutdown tasks
exit(); break;
case SIGINT:
echo "Stop pinging!n";
• SIGINT - CRTL-C $doPing = false; break;
case SIGUSR1:
•
echo "Caught SIGUSR1!n";
SIGTSTP - CTRL-Z break;
}
• SIGQUIT - CTRL- }
// Setup Signal Handlers
pcntl_signal(SIGTERM, "handler");
• SIGTERM - kill [pid] pcntl_signal(SIGQUIT, "handler");
pcntl_signal(SIGINT, "handler");
•
pcntl_signal(SIGUSR1, "handler");
SIGKILL - kill -9 [pid]
global $doPing; $doPing = true;
• SIGHUP - kill -hup [pid] while ($doPing) {
echo "Ping!" . PHP_EOL;
}
• SIGUSR1 - kill -10 [pid] // Send SIGUSR1 to current process id
posix_kill(posix_getpid(), SIGUSR1);

73. alerts &
timers
• pcntl_alarm ( )
• set alarm or timer
• signals SIGALRM
• each call cancels
previous set alarm
photo : istockphoto

74. alerts &
timers
• pcntl_alarm ( ) declare(ticks = 1);
function handler($signal) {
• set alarm or timer echo "Caught SIGALRMn";
pcntl_alarm(5);
• signals SIGALRM }
pcntl_signal(SIGALRM,
• each call cancels 'handler',
true);
previous set alarm pcntl_alarm(5);
while(1) { /* ... */ }

75. shared memory
• ftok for generating key
• shm_* & shmop_*
• shm php specific,
shmop more generic
• shmop is faster
• shm has variables

76. shared memory
• ftok for generating key • shm_attach,
shm_detach
• shm_* & shmop_*
• shm_has_var,
• shm php specific, shm_get_var,
shmop more generic shm_put_var,
shm_remove_var
• shmop is faster
• shm has variables • shm_remove
photo : istockphoto

78. shared memory
• ftok for generating key • shmop_open,
shmop_close
• shm_* & shmop_*
• shmop_read,
• shm php specific, shmop_write,
shmop more generic shmop_delete
• shmop is faster • shmop_size
• shm has variables
photo : istockphoto

80. alternative shared memory
• memcached
• high performance
• distributed
• lightweight
• object storage
• server pooling

81. resource access control
• semaphores
• provide exclusive
access to resources
• sem_* functions
• specify number of
allowed users

83. message queues
• semaphores
• provide exclusive
access to resources
• sem_* functions
• specify number of
allowed users

84. message queues
• semaphores • msg_get_queue,
msg_set_queue,
• provide exclusive msg_queue_exists,
access to resources msg_remove_queue
• sem_* functions • msg_send,
msg_receive,
• specify number of msg_stat_queue
allowed users
photo : istockphoto

87. ipcs | ipcrm | ipcmk
• queues, semaphores,
memory segments
• ipcs : status
• ipcmk : create
• ipcrm : remove

89. socket pairs
• two connected sockets
• stored in an array
• 2-way communication
• socket_create_pair
• socket_read,
socket_write
photo : http://photo.net/photodb/photo?photo_id=11216293

91. angels
photo by DragoArt.com - http://www.dragoart.com/tuts/9270/1/1/how-to-draw-tattoo-angels,-angel-tattoos.htm

92. monitoring
• angel scripts
• supervisord
• runit
• daemontools
• beware for zombies!
photo by Anthony Citrano - http://www.flickr.com/photos/zigzaglens/2956275907

93. angel scripts
• guardian angels
• pid file present: check
process is running
• not running: (remove
pid &) restart script
• angel scheduled cron
photo by Stu Hill Photography- www.flickr.com/photos/stuhillphotography/5526181346/

94. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

95. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

96. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

97. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

98. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

99. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

100. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

101. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

102. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

103. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

104. foreach ($daemons as $daemon) {
if (file_exists($daemon['pidfile'])) {
$pid = trim(file_get_contents($daemon['pidfile']));
if (!empty($pid)) {
// fake 0 signal to check if alive
if (posix_kill($pid, 0)) {
continue; // Next check
}
}
@unlink($daemon['pidfile']);
}
$pid = pcntl_fork();
if ($pid === 0) {
$sid = posix_setsid();
if ($sid != -1) {
pcntl_exec($daemon['command'], $daemon['params']);
}
}
}

105. supervisord
• process control system
• simple
• centralized
• efficient
• extensible
• http://supervisord.org

106. supervisord
• process control system [program:gearman_tika]
command=/path/to/script.php
• simple autostart=true
autorestart=true
• centralized logfile=/var/log/myscript.log
• efficient
• extensible
• http://supervisord.org

107. monit
• manage & monitor
processes, files,
directories & devices
• restart failed daemons
• control file with
service entries or
checks

108. check process processQueues with pidfile "/var/
run/amazium/processQueues.pid"
start = “/etc/init.d/processQueues start"
stop = "/etc/init.d/processQueues stop"
if does not exist then restart
if cpu usage is greater than 60 percent for
2 cycles then alert
if cpu usage > 98% for 5 cycles then restart
if 2 restarts within 3 cycles then timeout
alert foo@bar.baz

111. daemontools
• collection of tools to
manage services
• supervise : monitors a
service
• requires run script
with code to start
daemon

112. zombies
• defunct process
• child has finished but
is still in process table
• reaper for SIGCHLD
• pcntl_signal(SIGCHLD,
SIG_IGN);
wallpaper from Pozadia - http://dark.pozadia.org/wallpaper/Dawn-of-the-Zombies/

113. // Reaper to clean up zombies
function reaper($signal)
{
$pid = pcntl_waitpid(-1,
zombies
$status,
WNOHANG);
if ($pid == -1) {
// No child waiting.
} else {
if (pcntl_wifexited($signal)) {
echo 'Process $pid exited';
• defunct process
} else {
echo 'False alarm on $pid';
}
• child has finished but
// Check if more children ended
reaper($signal);
is still in process table }
pcntl_signal(SIGCHLD, 'reaper');
}
• exec wait system call // Install signal handler on SIGCHLD
pcntl_signal(SIGCHLD, 'reaper');
• reaper for SIGCHLD
// If there is no need to know when a
• pcntl_signal(SIGCHLD, // child has finished, you don’t need
// to use the reaper, use SIG_IGN:
SIG_IGN); pcntl_signal(SIGCHLD, SIG_IGN);

114. parallel processing
photo by Christian Guthier - http://www.flickr.com/photos/wheatfields/116810137

115. parallel processing
• concurrent processing
• spread work over
multiple processes
• daemonize parent
• create children
• do not change SID!
photo : istockphoto

116. step 1 : daemonize parent
// Daemonize the parent
$pid = pcntl_fork();
if ($pid == -1) {
writeToLog('Could not daemonize!');
exit(1);
} elseif ($pid > 0) {
writeToLog('Daemonized to ' . $pid);
exit(0);
} else { // Daemonized
umask(0);
$sid = posix_setsid();
if ($sid < 0) {
writeToLog('Could not detach session id.');
exit(1);
}
}

117. step 2 : create children
$parentPid = getmypid();
// Create our children
for ($i = 0; $i < MAX_CHILDREN; $i++) {
if (getmypid() == $parentPid) {
$pids[] = $pid = pcntl_fork(); // SPAWN NEW CHILD
if ($pid < 0) {
writeToLog('Could not fork!');
exit(1);
}
}
}
if (getmypid() == $parentPid) {
// Parent Code
} else {
// Child Code
}

118. distributed scripting
photo by Christian Guthier - http://www.flickr.com/photos/wheatfields/116810137

119. distribution?
• parallel processing on
multiple servers
• spread the load
• more efficient
• easier to scale

120. Gearman
• application framework
• farm out work
• open source
• multi-language
• fast
• flexible

121. ØMQ
• socket library
• designed for high
load / low latency
• flexible & advanced
• complicated
• http://vimeo.com/20605470

122. RabbitMQ
• broker architecture
• central node
• easy to use & deploy
• less scalable
• slower

123. Apache ActiveMQ
• middle ground
• broker architecture
• p2p architecture
• easier to implement
• less performant

124. Apache hadoop
• process large datasets
• MapReduce
• local processing &
storage
• failures detection at
application level
• http://vimeo.com/20955076

125. need more information on distribution?
• see workshop “Think like an ant, distribute the
workload” by Helgi Þormar Þorbjörnsson
• Video : http://vimeo.com/41013062
• Slides : http://www.slideshare.net/helgith/scale-
like-an-ant-distribute-the-workload-dpc-
amsterdam-2011

126. please rate my talk
https://joind.in/6226
twitter : @jkeppens
blog : blog.amazium.com