php代码运行流程(运行php需要的环境)

PHP执行这段代码会经过如下4个步骤(确切的来说,应该是PHP的语言引擎Zend)

1.Scanning(Lexing) ,将PHP代码转换为语言片段(Tokens)

2.Parsing, 将Tokens转换成简单而有意义的表达式

3.Compilation, 将表达式编译成Opocdes

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4.Execution, 顺次执行Opcodes,每次一条,从而实现PHP脚本的功能。

token_get_all()

将一段PHP代码 Scanning成Tokens;

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var_dump(token_get_all(‘’));

Array(

[0] => Array(

[0] => 376

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[1] =>

[2] => 1 )

[1] => Array(

[0] => 319

[1] => echo

[2] => 1 )

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[2] => Array(

[0] => 379

[1] =>

[2] => 1 )

[3] => Array(

[0] => 318

[1] => “Hello World”

[2] => 1 )

[4] => ;

[5] => Array(

[0] => 379

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[1] =>

[2] => 1 )

[6] => Array(

[0] => 378

[1] => ?>

[2] => 1 )

)