欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  后端开发

php中的require到底是函数还是语法

程序员文章站 2024-01-12 22:46:46
...
我发现两种用法都可以require('functions.php')require 'functions.php',那么它在php中到底是语法还是函数呢?我们能否在自己写php插件时也实现这样的用法?也就是可以这样用my_custom 'parms'

回复内容:

我发现两种用法都可以require('functions.php')require 'functions.php',那么它在php中到底是语法还是函数呢?我们能否在自己写php插件时也实现这样的用法?也就是可以这样用my_custom 'parms'

语法
Zend/zend_language_scanner.l

"eval" {
	return T_EVAL;
}

"include" {
	return T_INCLUDE;
}

"include_once" {
	return T_INCLUDE_ONCE;
}

"require" {
	return T_REQUIRE;
}

"require_once" {
	return T_REQUIRE_ONCE;
}

Zend/zend_language_parser.y

internal_functions_in_yacc:
		T_ISSET '(' isset_variables ')' { $$ = $3; }
	|	T_EMPTY '(' variable ')'	{ zend_do_isset_or_isempty(ZEND_ISEMPTY, &$$, &$3 TSRMLS_CC); }
	|	T_INCLUDE expr 			{ zend_do_include_or_eval(ZEND_INCLUDE, &$$, &$2 TSRMLS_CC); }
	|	T_INCLUDE_ONCE expr 	{ zend_do_include_or_eval(ZEND_INCLUDE_ONCE, &$$, &$2 TSRMLS_CC); }
	|	T_EVAL '(' expr ')' 	{ zend_do_include_or_eval(ZEND_EVAL, &$$, &$3 TSRMLS_CC); }
	|	T_REQUIRE expr			{ zend_do_include_or_eval(ZEND_REQUIRE, &$$, &$2 TSRMLS_CC); }
	|	T_REQUIRE_ONCE expr		{ zend_do_include_or_eval(ZEND_REQUIRE_ONCE, &$$, &$2 TSRMLS_CC); }
;

Zend/zend_compile.c

void zend_do_include_or_eval(int type, znode *result, const znode *op1 TSRMLS_DC) 
{
	zend_do_extended_fcall_begin(TSRMLS_C);
	{
		zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);

		opline->opcode = ZEND_INCLUDE_OR_EVAL;
		opline->result_type = IS_VAR;
		opline->result.var = get_temporary_variable(CG(active_op_array));
		SET_NODE(opline->op1, op1);
		SET_UNUSED(opline->op2);
		opline->extended_value = type;
		GET_NODE(result, opline->result);
	}
	zend_do_extended_fcall_end(TSRMLS_C);
}

require是 PHP 中的关键字。

f()这样的用法并不意味着f是函数。例如,print('hi'也可以,但是 print 并非函数。

相关标签: php