Cli the other SAPI confoo11

CLI, the other SAPI Confoo Thursday March 10th 2011 Montreal, Canada phpThijs FerynEvangelist+32 (0)9 218 79 06thijs@combellgroup.com

About me I’m an Evangelist at Combell

About me I’m a board member at PHPBenelux

I live in the wonderful city of Bruges MPBecker -‐ Bruges by Night hWp://www.ﬂickr.com/photos/galverson2/3715965933

Follow me on Twi+er: @ThijsFerynGive me feedback: h+p://joind.in/2852 Read my blog: h+p://blog.feryn.eu

SAPI according to Wikipedia“The Server Applica^on Programming Interface (SAPI) is the generic term used to designate direct module interfaces to web server applica^ons”

SAPI according to Wikipedia The way you interact with PHP

Common SAPIs • Apache/Apache 2 • CGI • FastCGI • ISAPI • CLI • GTK

The CLI SAPI according to php.net As of version 4.3.0, PHP supports a new SAPI type (Server Applica^on Programming Interface) named CLI which means Command Line Interface. As the name implies, this SAPI type main focus is on developing shell (or desktop as well) applica^ons with PHP

The CLI SAPI according to php.netPHP script execu^on via the command line interface

When to use• In crons• For batch tasks• For worker processes• Daemons• Process control• Interac^on with other binaries

CLI 101

CLI 101The PHP binaryPassing argumentsReading from STDINI/O with pipes

CLI 101Invoking a script with the PHP binaryphp file.php

CLI 101 Passing argumentsphp file.php arg1 arg2

CLI 101 interpreting arguments<?phpecho "Number of arguments {$argc}n";foreach($argv as $key=>$argument){ echo "Argument # {$key}: {$argument}n"; }

CLI 101 interpreting arguments Argument Argument count array<?phpecho "Number of arguments {$argc}n";foreach($argv as $key=>$argument){ echo "Argument # {$key}: {$argument}n"; }

CLI 101 The PHP ﬁle is an interpreting arguments argument too$ php args.php arg1 arg2Number of arguments 3Argument # 0: args.phpArgument # 1: arg1Argument # 2: arg2$

CLI 101 interpreting arguments$_SERVER[‘argc’] $argc$_SERVER[‘argv’] $argv !!! register_argc_argv !!!

CLI 101 getopt<?php$arguments = getopt(ab:c::);var_dump($arguments);

CLI 101 getopt Op^onal Flag (no value) value<?php$arguments = getopt(ab:c::);var_dump($arguments); Required value

CLI 101php getopt.php -‐a -‐b 2 -‐c3array(3) { ["a"]=> No bool(false) ["b"]=> spacing for string(1) "2" op^onal ["c"]=> arguments string(1) "3"}

CLI 101 getopt: longopts<?php$arguments = getopt(,array(arg1,arg2:,arg3::));var_dump($arguments);

CLI 101php getopt2.php -‐-‐arg1 -‐-‐arg2 123 -‐-‐arg3=xarray(3) { ["arg1"]=> bool(false) Mind ["arg2"]=> the “=” sign string(3) "123" ["arg3"]=> string(1) "x"}

CLI 101 REading From STDIN<?php$handle = fopen(php://stdin,r);while(!feof($handle)){ $line = trim(fgets($handle)); if(strlen($line) > 0){ echo strrev($line).PHP_EOL; }}fclose($handle);

CLI 101$ cat test.txt | php stdin.php enOowTeerhT$

CLI 101$ cat test.txt | php stdin.php enOowT Output Convert eerhT$ ﬁle output to input with pipes

Comparing the Apache & CLI SAPI

Comparing the Apache & CLI SAPI Web based SAPI’s• HTTP is a stateless protocol• Request/response based• Limited interac^on• Sessions & cookies as workaround• Execu^on ^meouts• Limited request/response size

Comparing the Apache & CLI SAPI CLI SAPI• Controlable state• Controlable script execuôn• Con^nuous interacôn• No need for sessions• No execuôn ^meouts

Measuring the state

Input & output

Input & output Web CLI• $_SERVER • $_SERVER• $_GET • $argc/$argv• $_POST • $_ENV• $_COOKIE • getopt()• $_SESSION • STDIN/STDOUT/ STDERR• $_ENV

Change your mindset

Change your mindset Don’t use sessions & cookies Just use local variables

Change your mindset Don’t “get” your input Just “read” it

Change your mindset Don’t bundle your output You can use distributed output

Change your mindset If you don’t need HTTP, use CLI E.g. cronjobs Avoid overhead

Change your mindset Current directory != webroot CLI scripts are ➡Use dirname(__FILE__) executable everywhere➡Use chdir()➡Use getcwd()

The PHP binary php

The PHP binaryUsage: php [options] [-‐f] <file> [-‐-‐] [args...] php [options] -‐r <code> [-‐-‐] [args...] php [options] [-‐B <begin_code>] -‐R <code> [-‐E <end_code>] [-‐-‐] [args...] php [options] [-‐B <begin_code>] -‐F <file> [-‐E <end_code>] [-‐-‐] [args...] php [options] -‐-‐ [args...] php [options] -‐a

InteracOve mode (-‐a) $ php -‐a Interactive shell php > echo 5+8; 13 php > function addTwo($n) php > { php { return $n + 2; php { } php > var_dump(addtwo(2)); int(4) php >

InteracOve mode (-‐a) $ php -‐a Tab Interactive shell comple^on php > stri[TAB][TAB] strip_tags stripcslashes stripslashes stristr stripos php > stri

Run code (-‐r) $ php -‐r "echo date(Y-‐m-‐d H:i:s);" 2011-‐03-‐02 22:04:45 $

Conﬁg directory (-‐c) $ php -‐c /custom/dir/php.ini script.php

Deﬁne custom INI seSng (-‐d) $ php -‐d max_execution_time=20 -‐r $foo = ini_get("max_execution_time"); var_dump ($foo); string(2) "20" $

Get INI informaOon (-‐i) Filtering items $ php -‐i | grep “log_” define_syslog_variables => Off => Off log_errors => On => On log_errors_max_len => 1024 => 1024 $

Syntax/lint check (-‐l) Only checks parse errors $ php -‐l myFile.php No syntax errors detected in myFile.php $

Module list (-‐m) $ php -‐m [PHP Modules] bcmath bz2 calendar Core ctype curl date dba $

Syntax highlighOng (-‐s)<?phpecho "Hello world";$ php -‐s helloworld.php > helloworld.html$

Syntax highlighOng (-‐s)<code><?php echo <spanstyle="color:#DD0000">"Hello world"<spanstyle="color: #007700">;<?phpecho "Hello world";

Version info (-‐v) $ php -‐v PHP 5.3.3-‐1ubuntu9.3 with Suhosin-‐Patch (cli) (built: Jan 12 2011 16:07:38) Copyright (c) 1997-‐2009 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-‐2010 Zend Technologies $

FuncOon reﬂecOon (-‐-‐rf)$ php -‐-‐rf json_encodeFunction [ <internal:json> function json_encode ] { -‐ Parameters [2] { Parameter #0 [ <required> $value ] Parameter #1 [ <optional> $options ] }}$

Class reﬂecOon (-‐-‐rf) $ php -‐-‐rc stdclass Class [ <internal:Core> class stdClass ] { -‐ Constants [0] { } -‐ Static properties [0] { } -‐ Static methods [0] { } -‐ Properties [0] { } -‐ Methods [0] { } } $

Extension reﬂecOon (-‐-‐re)$ php -‐-‐re jsonExtension [ <persistent> extension #20 json version 1.2.1 ] {... -‐ Functions { Function [ <internal:json> function json_encode ] { -‐ Parameters [2] { Parameter #0 [ <required> $value ] Parameter #1 [ <optional> $options ] } }...}

Extension INI informaOon (-‐-‐ri) $ php -‐-‐ri pdo PDO PDO support => enabled PDO drivers => mysql, sqlite, sqlite2 $

Back on track

Back to I/O

STDIN <?php $handle = fopen(php://stdin,r); while(!feof($handle)){ $line = trim(fgets($handle)); if(strlen($line) > 0){ echo strrev($line).PHP_EOL; } } fclose($handle);

STDIN <?php while(!feof(STDIN)){ $line = trim(fgets(STDIN)); if(strlen($line) > 0){ echo strrev($line).PHP_EOL; } }

STDIN Stream that is opened <?php by default while(!feof(STDIN)){ $line = trim(fgets(STDIN)); if(strlen($line) > 0){ echo strrev($line).PHP_EOL; } }

STDIN The Stream that is opened proof ! by default $ php -‐r "var_dump(STDIN);" resource(1) of type (stream) $

Wordcount example<?php$wordArray = array();while(!feof(STDIN)){ $line = trim(fgets(STDIN)); if(strlen($line) > 0){ foreach(preg_split(/[s]+/,$line) as $word){ if(!array_key_exists($word,$wordArray)){ $wordArray[$word] = 0; } $wordArray[$word]++; } }}ksort($wordArray);foreach($wordArray as $word=>$count){ echo "$word: $count".PHP_EOL;}

Wordcount example$ cat wordcount.txt CanadaThijsCanadaThijsThijsConfoo$ cat wordcount.txt | php wordcount.php Canada: 2Confoo: 1Thijs: 3$

STDOUT STDOUT == echo<?php$handle = fopen(php://stdout,w);fwrite($handle,Hello world);fclose($handle);

STDOUT<?phpfwrite(STDOUT,Hello world);

STDERR<?php$handle = fopen(php://stderr,w);fwrite($handle,Serious error!);fclose($handle);

STDERR<?phpfwrite(STDERR,Serious error!);

Mixing STDOUT & STDERR<?phpfwrite(STDOUT,STDOUT output.PHP_EOL);fwrite(STDERR,STDERR output.PHP_EOL);$ php stdmix.php STDOUT outputSTDERR output$

Mixing STDOUT & STDERR<?php Looks fwrite(STDOUT,STDOUT output.PHP_EOL); the samefwrite(STDERR,STDERR output.PHP_EOL);$ php stdmix.php STDOUT outputSTDERR output$

Mixing STDOUT & STDERR$ php stdmix.php > /dev/null STDERR output$$ php stdmix.php &> /dev/null$

Mixing STDOUT & STDERR STDOUT is caught$ php stdmix.php > /dev/null STDOUT STDERR output$ & STDERR are caught$ php stdmix.php &> /dev/null$

AlternaOve output<?phpfclose(STDOUT);$handle = fopen(realpath(dirname(__FILE__)./output.txt),a);echo "Hello world!".PHP_EOL;fclose($handle);

AlternaOve output<?phpfclose(STDOUT);$handle = fopen(realpath(dirname(__FILE__)./output.txt),a);echo "Hello world!".PHP_EOL;fclose($handle); echo output is wriWen to ﬁle

Piping$ php -‐r for($i=0;$i<10;$i++) echo $i.PHP_EOL;0123456789$ php -‐r for($i=0;$i<10;$i++) echo $i.PHP_EOL; | wc -‐l 10$

Readline<?php$name = readline("Whats your name: ");$location = readline("Where do you live: ");echo PHP_EOL."Hello $name from $locationn";$ php readline.php Whats your name: ThijsWhere do you live: BelgiumHello Thijs from Belgium$

Shebang !#!/usr/bin/php<?phpecho "Hello world".PHP_EOL;$ chmod +x shebang.php$ ./shebang.phpHello world$

Encore

PCNTL according to php.net Process Control support in PHP implements the Unix style of process creaôn, program execuôn, signal handling and process terminaôn.

Process Control should not be enabled within a web server environment and unexpected results may happen if any Process Control func^ons are used within a web server environment.

Forking according to Wikipedia In compu^ng, when a process forks, it creates a copy of itself

Forking PID value determines context Copy <?php program $pid = pcntl_fork();if ($pid == -1) { execu^on //Forking failed} else if ($pid) { //Parent logic} else { PID of child //Child logic} process

Forking<?php$pid = pcntl_fork();if ($pid == -1) { die(could not fork);} else if ($pid) { echo "[parent] Starting".PHP_EOL; pcntl_wait($status); echo "[parent] Exiting".PHP_EOL;} else { echo "[child] Starting".PHP_EOL; for($i=0;$i<3;$i++){ echo "[child] Loop $i".PHP_EOL; sleep(1); } echo "[child] Exiting".PHP_EOL; exit;}

Forking Perform forking<?php$pid = pcntl_fork();if ($pid == -1) { die(could not fork); Wait for child } else if ($pid) { termina^on echo "[parent] Starting".PHP_EOL; pcntl_wait($status); echo "[parent] Exiting".PHP_EOL;} else { echo "[child] Starting".PHP_EOL; for($i=0;$i<3;$i++){ echo "[child] Loop $i".PHP_EOL; sleep(1); } echo "[child] Exiting".PHP_EOL; exit;}

SignalsA signal is a limited form of inter-‐process communicaôn used in Unix, Unix-‐like, and other POSIX-‐compliant opera^ng systems. Essenâlly it is an asynchronous no^ficaôn sent to a process in order to no^fy it of an event that occurred.

Signals<?phpdeclare(ticks = 1);function sig_handler($signo){ switch ($signo) { case SIGTERM: echo PHP_EOL."SIGTERM".PHP_EOL; exit(); break; case SIGINT: echo PHP_EOL."SIGINT".PHP_EOL; exit(); break; }}pcntl_signal(SIGTERM, "sig_handler");pcntl_signal(SIGINT, "sig_handler");sleep(100);

Signals<?phpdeclare(ticks = 1); Process termina^onfunction sig_handler($signo){ switch ($signo) { case SIGTERM: Process echo PHP_EOL."SIGTERM".PHP_EOL; exit(); break; case SIGINT: interrup^on echo PHP_EOL."SIGINT".PHP_EOL; exit(); break; Catch signals }}pcntl_signal(SIGTERM, "sig_handler");pcntl_signal(SIGINT, "sig_handler");sleep(100);

POSIX process control funcOons<?phpecho "[prefork] PID: ".posix_getpid().", parent PID: ".posix_getppid().PHP_EOL;$pid = pcntl_fork();if ($pid == -1) { die(could not fork);} else if ($pid == 0) { echo "[child] PID: ".posix_getpid().", parent PID: ".posix_getppid().PHP_EOL; exit;} else { echo "[parent] PID: ".posix_getpid().", parent PID: ".posix_getppid().PHP_EOL; pcntl_wait($status);}

Parent PID Prefork PID POSIX process c== funcOons of parent ontrol == <?php session PID parent PIDecho "[prefork] PID: ".posix_getpid().", parent PID: ".posix_getppid().PHP_EOL;$pid = pcntl_fork();if ($pid == -1) { die(could not fork); child PID} else if ($pid == 0) { child PID echo "[child] PID: ".posix_getpid().", parent PID: ".posix_getppid().PHP_EOL; exit; parent } else { PID echo "[parent] PID: ".posix_getpid().", parent PID: ".posix_getppid().PHP_EOL; pcntl_wait($status);}

POSIX process control funcOons<?php$pid=pcntl_fork();if ($pid == -1) { die("could not fork");} else if ($pid) { $exists = posix_kill($pid,0)?still:no longer; echo "[parent] Child process $pid $exists exists".PHP_EOL; echo "[parent] Killing child process $pid".PHP_EOL; posix_kill($pid,SIGTERM); echo "[parent] Child process $pid killed".PHP_EOL; pcntl_wait($status); $exists = posix_kill($pid,0)?still:no longer; echo "[parent] Child process $pid $exists exists".PHP_EOL;} else { while(true){ sleep(100); } exit;}

POSIX process control funcOons “KILL 0” checks <?php$pid=pcntl_fork(); existenceif ($pid == -1) { die("could not fork");} else if ($pid) { Send SIGTERM $exists = posix_kill($pid,0)?still:no longer; echo "[parent] Child process $pid $exists exists".PHP_EOL; signal echo "[parent] Killing child process $pid".PHP_EOL; posix_kill($pid,SIGTERM); echo "[parent] Child process $pid killed".PHP_EOL; pcntl_wait($status); $exists = posix_kill($pid,0)?still:no longer; echo "[parent] Child process $pid $exists exists".PHP_EOL;} else { while(true){ Child process sleep(100); } is dead exit;}

Some PCNTL guidelines✓Detect your CWD✓Use PID ﬁles✓Control you ﬁle privileges✓Detach you session✓Avoid rogue child processes✓Cleanup your garbage

Talk dedicated to process control Check this guy out ! in PHP Jeroen Keppens: @jkeppens http://www.slideshare.net/jkeppens/php-‐in-‐the-‐dark

Thanks !

Cli the other SAPI confoo11

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