<>PHP call shell command

<> preface

Because I want to use it php call python script , So I thought we could use it php call shell Method implementation of command .
php edition :php7.0

<> Three methods

<>1.system

system — Executing external procedures , And display the output

How to use functions
system ( string $command [, int &$return_var ] ) : string
example:
<?php $last_line = system('ls',$return_val); echo(“last line:”.$last_line);
echo(“return:”.$return_val);
explain : Yes shell command , And output its return result directly ;
The return result of the function is shell The last line of the command output ;
$return_val by shell The return result of the command .

<>2.exec

exec — Execute an external program
exec ( string $command [, array &$output [, int &$return_var ]] ) : string
example:
<?php exec('ls',$out); var_dump($out);
explain :exec The return result of the function is shell The last line of the command output ;
$output by shell Command output content ;
$return_val by shell The command returns the result ;

<>3.passthru

passthru — Execute the external program and display the original output
passthru ( string $command [, int &$return_var ] ) : void
example:
<?php passthru('ls',$res); echo($res);
explain : When executed Unix The command outputs binary data , And it needs to be sent directly to the browser , You need to use this function instead exec() or system() function . By setting
Content-type by image/gif, Then call pbmplus Program output gif file , You can start from PHP Script output image to browser directly

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