ZendCon 2011 : PHP in the Dark

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

shell scripting photo : istockphoto

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

php-cli • server api (sapi) <?php • coordinates php echo "Hello World"; lifecycle ?> • command line interface • shebanghttp://www.slideshare.net/combell/cli-the-other-sapi-confoo11

php-cli • server api (sapi) #!/usr/bin/php <?php • coordinates php echo "Hello World"; lifecycle ?> • command line interface • shebanghttp://www.slideshare.net/combell/cli-the-other-sapi-confoo11

php-cli • server api (sapi) #!/usr/bin/php <?php • coordinates php echo "Hello World"; lifecycle ?> • command line interface ./00-hello-world.php • shebanghttp://www.slideshare.net/combell/cli-the-other-sapi-confoo11

php-cli • server api (sapi) #!/usr/bin/php <?php • coordinates php echo "Hello World"; lifecycle ?> • command line interface ./00-hello-world.php • shebang Hello Worldhttp://www.slideshare.net/combell/cli-the-other-sapi-confoo11

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 )

cronjobs• schedule task * * * * * 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

cronjobs; define constantsAPPLICATION_ENVIRONMENT = developmentDB_SERVER = db1.somehost.com; run every day at 4:3030 4 * * * /path/to/somescript.php -daily; run every 5 minutes*/5 * * * * /path/to/somescript.php; run every monday and thursday, at midnight and 9AM0,9 * * * 1,4 /path/to/somescript

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

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

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

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

./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)

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

// Define short options $short = "hv"; $short.= "u:"; // requiredgetopt ( ) $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 options

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

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

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

./02-basic-getopt.php -u Jeroen -h -ppasswdArray( [u] => Jeroen [p] => passwd [h] =>)./02-basic-getopt.php -u -h -p passwdArray( [u] => -h [p] =>)

zend |getopt• Zend_Console_Getop t• options linked• value type validation• usage message• object returned photo : istockphoto

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

./03-zend-getopt.php -h

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

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

// Autocompletionfunction autocomplete() { return (history, clear, cls, quit, exit);}readline_completion_function(autocomplete);// Initiate historyif (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

./readline.php

outputhelpers• pear Console_*• ez consoletools• text formatting• progressbars• tables

ncurses• terminfo format• padding• coloring• windows• keyboard / mouse input

daemonsphoto by PSA Peugeot Citroen - http://bit.ly/peugeot-car-welding

steps to create a daemon• Fork off the parent process

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

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

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

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

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

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/

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

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

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 touch($testFile); mask // resulting permissions: // 0666 - 0007 = 0660

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

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

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

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

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

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

// Log file to write to$logfile = /tmp/some-log-file.log;// Close standard I/O descriptorsfclose(STDIN);fclose(STDOUT);fclose(STDERR);// First 3 descriptors fill up the blanks$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

$pid = pcntl_fork();if ($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);}

$pid = pcntl_fork(); fork off the parent processif ($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);}

$pid = pcntl_fork(); set the user creation maskif ($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);}

$pid = pcntl_fork(); open any log filesif ($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);}

$pid = pcntl_fork(); detach current sessionif ($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);}

$pid = pcntl_fork(); change current working dirif ($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);}

$pid = pcntl_fork(); close open file descriptorsif ($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);}

$pid = pcntl_fork(); payloadif ($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);}

$pid = pcntl_fork();if ($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);}

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

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

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

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/

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]); } }}

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

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

// 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 echo "$aPid is dead."; } [pid]

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");• SIGKILL - kill -9 [pid] pcntl_signal(SIGUSR1, "handler"); global $doPing; $doPing = true;• SIGHUP - kill -hup while ($doPing) { echo "Ping!" . PHP_EOL; [pid] } // Send SIGUSR1 to current process id posix_kill(posix_getpid(), SIGUSR1);

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

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, previous set alarm true); pcntl_alarm(5); while(1) { /* ... */ }

zombies• defunct process• child has finished but is still in the process table• exec wait system call• reaper for SIGCHLD• use SIG_IGN wallpaper from Pozadia - http://dark.pozadia.org/wallpaper/Dawn-of-the-Zombies/

// 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 the process } pcntl_signal(SIGCHLD, reaper); table } // Install signal handler on SIGCHLD• exec wait system call pcntl_signal(SIGCHLD, reaper);• reaper for SIGCHLD // If there is no need to know when a // child has finished, you don’t need // to use the reaper, use SIG_IGN:• use SIG_IGN pcntl_signal(SIGCHLD, SIG_IGN);

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

parallel processing• concurrent processing• spread work over multiple processes• daemonize parent• create children photo : istockphoto

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); }}

step 2 : create children$parentPid = getmypid();// Create our childrenfor ($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}

inter-processcommunication• parent-child• child-child• signals• socket pairs• message queues photo : istockphoto

shared resources• locking via semaphore• shmop (shm_*)• memcache(d)• apc photo : istockphoto

distributed processing• Gearman• ØMQ• RabbitMQ• Apache ActiveMQ• Apache Hadoop• Cloud services

please rate my talkhttp://joind.in/4029 twitter : @jkeppens blog : blog.amazium.com

ZendCon 2011 : PHP in the Dark

by Jeroen Keppens on Oct 23, 2011

Accessibility

Categories

Tags

Upload Details

Usage Rights

2 Embeds 13

Statistics

ZendCon 2011 : PHP in the Dark — Presentation Transcript

http://a0.twimg.com	11
http://paper.li	2