我發(fā)現(xiàn)兩種用法都可以require('functions.php')和require 'functions.php'，那么它在php中到底是語法還是函數(shù)呢？我們能否在自己寫php插件時也實現(xiàn)這樣的用法？
2 回答
慕哥9229398
TA貢獻(xiàn)1877條經(jīng)驗 獲得超6個贊
語法
Zend/zend_language_scanner.l
<ST_IN_SCRIPTING>"eval" { return T_EVAL;
}
<ST_IN_SCRIPTING>"include" { return T_INCLUDE;
}
<ST_IN_SCRIPTING>"include_once" { return T_INCLUDE_ONCE;
}
<ST_IN_SCRIPTING>"require" { return T_REQUIRE;
}
<ST_IN_SCRIPTING>"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);
}
HUX布斯
TA貢獻(xiàn)1876條經(jīng)驗 獲得超6個贊
require是 PHP 中的關(guān)鍵字。
f()這樣的用法并不意味著f是函數(shù)。例如，print('hi'也可以，但是 print 并非函數(shù)。
- 2 回答
- 0 關(guān)注
- 159 瀏覽
添加回答
舉報
0/150
提交
取消