26.预定义变量

... //  省略zend_hash_init(&EG(symbol_table), 50, NULL, ZVAL_PTR_DTOR, 0);{    zval *globals;    ALLOC_ZVAL(globals);    Z_SET_REFCOUNT_P(globals, 1);    Z_SET_ISREF_P(globals);    Z_TYPE_P(globals) = IS_ARRAY;    Z_ARRVAL_P(globals) = &EG(symbol_table);    zend_hash_update(&EG(symbol_table), "GLOBALS", sizeof("GLOBALS"),        &globals, sizeof(zval *), NULL);      //  添加全局变量$GLOBALS}... //  省略

/* {{{ php_hash_environment */int php_hash_environment(TSRMLS_D){        char *p;        unsigned char _gpc_flags[5] = {0, 0, 0, 0, 0};        zend_bool jit_initialization = (PG(auto_globals_jit) && !PG(register_globals) && !PG(register_long_arrays));        struct auto_global_record {                char *name;                uint name_len;                char *long_name;                uint long_name_len;                zend_bool jit_initialization;        } auto_global_records[] = {                { "_POST", sizeof("_POST"), "HTTP_POST_VARS", sizeof("HTTP_POST_VARS"), 0 },                { "_GET", sizeof("_GET"), "HTTP_GET_VARS", sizeof("HTTP_GET_VARS"), 0 },                { "_COOKIE", sizeof("_COOKIE"), "HTTP_COOKIE_VARS", sizeof("HTTP_COOKIE_VARS"), 0 },                { "_SERVER", sizeof("_SERVER"), "HTTP_SERVER_VARS", sizeof("HTTP_SERVER_VARS"), 1 },                { "_ENV", sizeof("_ENV"), "HTTP_ENV_VARS", sizeof("HTTP_ENV_VARS"), 1 },                { "_FILES", sizeof("_FILES"), "HTTP_POST_FILES", sizeof("HTTP_POST_FILES"), 0 },        };        size_t num_track_vars = sizeof(auto_global_records)/sizeof(struct auto_global_record);        size_t i;        /* jit_initialization = 0; */        for (i=0; i<num_track_vars; i++) {                PG(http_globals)[i] = NULL;        }        for (p=PG(variables_order); p && *p; p++) {                switch(*p) {                        case 'p':                        case 'P':                                if (!_gpc_flags[0] && !SG(headers_sent) && SG(request_info).request_method && !strcasecmp(SG(request_info).request_method, "POST")) {                                        sapi_module.treat_data(PARSE_POST, NULL, NULL TSRMLS_CC);   /* POST Data */                                        _gpc_flags[0] = 1;                                        if (PG(register_globals)) {                                                php_autoglobal_merge(&EG(symbol_table), Z_ARRVAL_P(PG(http_globals)[TRACK_VARS_POST]) TSRMLS_CC);                                        }                                }                                break;                        case 'c':                        case 'C':                                if (!_gpc_flags[1]) {                                        sapi_module.treat_data(PARSE_COOKIE, NULL, NULL TSRMLS_CC); /* Cookie Data */                                        _gpc_flags[1] = 1;                                        if (PG(register_globals)) {                                                php_autoglobal_merge(&EG(symbol_table), Z_ARRVAL_P(PG(http_globals)[TRACK_VARS_COOKIE]) TSRMLS_CC);                                        }                                }                                break;                        case 'g':                        case 'G':                                if (!_gpc_flags[2]) {                                        sapi_module.treat_data(PARSE_GET, NULL, NULL TSRMLS_CC);    /* GET Data */                                        _gpc_flags[2] = 1;                                        if (PG(register_globals)) {                                                php_autoglobal_merge(&EG(symbol_table), Z_ARRVAL_P(PG(http_globals)[TRACK_VARS_GET]) TSRMLS_CC);                                        }                                }                                break;                        case 'e':                        case 'E':                                if (!jit_initialization && !_gpc_flags[3]) {                                        zend_auto_global_disable_jit("_ENV", sizeof("_ENV")-1 TSRMLS_CC);                                        php_auto_globals_create_env("_ENV", sizeof("_ENV")-1 TSRMLS_CC);                                        _gpc_flags[3] = 1;                                        if (PG(register_globals)) {                                                php_autoglobal_merge(&EG(symbol_table), Z_ARRVAL_P(PG(http_globals)[TRACK_VARS_ENV]) TSRMLS_CC);                                        }                                }                                break;                        case 's':                        case 'S':                                if (!jit_initialization && !_gpc_flags[4]) {                                        zend_auto_global_disable_jit("_SERVER", sizeof("_SERVER")-1 TSRMLS_CC);                                        php_register_server_variables(TSRMLS_C);                                        _gpc_flags[4] = 1;                                        if (PG(register_globals)) {                                                php_autoglobal_merge(&EG(symbol_table), Z_ARRVAL_P(PG(http_globals)[TRACK_VARS_SERVER]) TSRMLS_CC);                                        }                                }                                break;                }        }        /* argv/argc support */        if (PG(register_argc_argv)) {                php_build_argv(SG(request_info).query_string, PG(http_globals)[TRACK_VARS_SERVER] TSRMLS_CC);        }        for (i=0; i<num_track_vars; i++) {                if (jit_initialization && auto_global_records[i].jit_initialization) {                        continue;                }                if (!PG(http_globals)[i]) {                        ALLOC_ZVAL(PG(http_globals)[i]);                        array_init(PG(http_globals)[i]);                        INIT_PZVAL(PG(http_globals)[i]);                }                Z_ADDREF_P(PG(http_globals)[i]);                zend_hash_update(&EG(symbol_table), auto_global_records[i].name, auto_global_records[i].name_len, &PG(http_globals)[i], sizeof(zval *), NULL);                if (PG(register_long_arrays)) {                        zend_hash_update(&EG(symbol_table), auto_global_records[i].long_name, auto_global_records[i].long_name_len, &PG(http_globals)[i], sizeof(zval *), NULL);                        Z_ADDREF_P(PG(http_globals)[i]);                }        }        /* Create _REQUEST */        if (!jit_initialization) {                zend_auto_global_disable_jit("_REQUEST", sizeof("_REQUEST")-1 TSRMLS_CC);                php_auto_globals_create_request("_REQUEST", sizeof("_REQUEST")-1 TSRMLS_CC);        }        return SUCCESS;}

/* {{{ php_post_entries[]*/static sapi_post_entry php_post_entries[] = {{ DEFAULT_POST_CONTENT_TYPE, sizeof(DEFAULT_POST_CONTENT_TYPE)-1, sapi_read_standard_form_data, php_std_post_handler },{ MULTIPART_CONTENT_TYPE, sizeof(MULTIPART_CONTENT_TYPE)-1, NULL, rfc1867_post_handler },{ NULL, 0, NULL, NULL }};/* }}} */#define MULTIPART_CONTENT_TYPE "multipart/form-data"#define DEFAULT_POST_CONTENT_TYPE "application/x-www-form-urlencoded"

API_API SAPI_POST_HANDLER_FUNC(rfc1867_post_handler){//若干省略    while (!multipart_buffer_eof(mbuff TSRMLS_CC)){        if (!multipart_buffer_headers(mbuff, &header TSRMLS_CC)) {        goto fileupload_done;    }//若干省略    /* Possible Content-Type: */    if (cancel_upload || !(cd = php_mime_get_hdr_value(header, "Content-Type"))) {        cd = "";    } else {     /* fix for Opera 6.01 */        s = strchr(cd, ';');        if (s != NULL) {            *s = '\0';        }    }//若干省略    /* Add $foo[type] */    if (is_arr_upload) {            snprintf(lbuf, llen, "%s[type][%s]", abuf, array_index);    } else {        snprintf(lbuf, llen, "%s[type]", param);    }    register_http_post_files_variable(lbuf, cd, http_post_files, 0 TSRMLS_CC);    //若干省略    }}

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http://www.php-internals.com/book/?p=chapt03/03-03-pre-defined-variable