PHP5.4的变化关注---What has changed in PHP 5.4.x

What has changed in PHP 5.4.x

Most improvements in PHP 5.4.x have no impact on existing code. There are a few
incompatibilities and new
features that should be considered, and code should be tested before switching PHP versions in production environments.

1. Backward Incompatible Changes ：一些内容将不兼容

1)不再支持安全模式，
2) 移除魔术引用，
3) 移除全局变量php.ini设置，
4) 移除Call-time
pass by reference（如call_user_func_array('function', array(&$a)
不支持)
5)break/continue 不接受参数，但保留接受静态参数
6)必须设置时区timezone

7) 注意非数字数组键值 详看:PHP5.4中一个需要注意的变化(Chained
string offsets)

8) 数组转字符串提示

E_NOTICE

level
error
8) 使用超全局变量做函数参数将导致致命错误

function foo($_GET, $_POST) {}
//在5.3是没问题的.
//php5.4出现:Fatal error: Cannot re-assign auto-global variable _GET in /opt/php-5.4.0/test.php on line 4

Although most existing PHP 5 code should work without changes, please take note of some backward incompatible changes:

Safe
mode is no longer supported. Any applications that rely on safe mode may need adjustment, in terms of security.

Magic
quotes has been removed. Applications relying on this feature may need to be updated, to avoid security issues. get_magic_quotes_gpc() and get_magic_quotes_runtime() now
always return

FALSE

.set_magic_quotes_runtime() raises
an

E_CORE_ERROR

level error.

The register_globals and register_long_arrays php.ini directives
have been removed.

Call-time
pass by reference has been removed.

The break and continue statements
no longer accept variable arguments (e.g., break 1 + foo() * $bar;). Static arguments still work, such as break 2;.

In the date
and time extension, the timezone can no longer be set using the TZ environment variable. Instead you have to specify a timezone using the date.timezone php.ini option
or date_default_timezone_set() function.
PHP will no longer attempt to guess the timezone, and will instead fall back to "UTC" and issue a

E_WARNING

.

Non-numeric string offsets - e.g. $a['foo'] where $a is a string - now return false on isset() and
true on empty(),
and produce a

E_WARNING

if you try to use them. Offsets of types double, bool and null produce a

E_NOTICE

.
Numeric strings (e.g. $a['2']) still work as before. Note that offsets like '12.3' and '5 foobar' are considered non-numeric and produce a

E_WARNING

,
but are converted to 12 and 5 respectively, for backward compatibility reasons. Note: Following code returns different result. $str='abc';var_dump(isset($str['x'])); // false for PHP 5.4 or later, but
true for 5.3 or less

Converting an array to a string will now generate an

E_NOTICE

level error, but the result
of the cast will still be the string "Array".

Turning

NULL

,

FALSE

,
or an empty string into an object by adding a property will now emit an

E_WARNING

level error, instead of

E_STRICT

.

Parameter names that shadow super globals now cause a fatal error. This prohibits code like function foo($_GET, $_POST) {}.

The Salsa10 and Salsa20 hash
algorithms have been removed.

array_combine() now
returns array() instead of

FALSE

when two empty arrays are provided as parameters.

If you use htmlentities() with
asian character sets, it works like htmlspecialchars() -
this has always been the case in previous versions of PHP, but now an

E_STRICT

level error is emitted.

The following keywords are now reserved,
and may not be used as names by functions, classes, etc.

trait

callable

insteadof

The following functions have been removed from PHP:

define_syslog_variables()

import_request_variables()

session_is_registered(), session_register() and session_unregister().

The aliases mysqli_bind_param(), mysqli_bind_result(), mysqli_client_encoding(), mysqli_fetch(), mysqli_param_count(), mysqli_get_metadata(), mysqli_send_long_data(),
mysqli::client_encoding() and mysqli_stmt::stmt().

2. New features 新功能

1）traits特性的功能相当使一个类可以存在两个父类。在php5.4之前，一个类不能继承两个父类。

2）数组可以类似c/c++写法
3）Class::{expr}() 这个写法有点迷糊
4）支持二进制数值，即二进制直接写赋值给变量：

$bin  = 0b1101;
echo $bin;
//13

而不必使用bin2dec转换成十进制
想看大鸟：二进制直接量(binary number format)
5）上传进度支持(Upload
progress in sessions)
6）php5.4可以编译成命令行模式的server

PHP 5.4.0 offers a wide range of new features:

Support for traits has
been added.

Short array syntax has been added, e.g. $a = [1, 2, 3, 4]; or $a = ['one' => 1, 'two' => 2, 'three' => 3, 'four' => 4];.

Function array dereferencing has been added, e.g. foo()[0].

Closures now
support $this.

<?= is now always available, regardless of the short_open_tag php.ini option.

Class member access on instantiation has been added, e.g. (new Foo)->bar().

Class::{expr}() syntax is now supported.

Binary number format has been added, e.g. 0b001001101.

Improved parse error messages and improved incompatible arguments warnings.

The session extension can now track the upload
progress of files.

Built-in development web
server in CLI mode.

Changes in SAPI modules

A new SAPI module named cli-server is now available.

Added CLI option --rz which shows information of the named Zend extension.

Added shortcut #inisetting=value to change php.ini settings at run-time in interactive readline CLI

Added apache compatible functions: apache_child_terminate(), getallheaders(), apache_request_headers() and apache_response_headers() for
FastCGI SAPI.

PHP-FPM: Added the process.max setting, to control the number of processes that FPM can fork.

3 . Deprecated features in PHP 5.4.x 弃用的功能

Deprecated functions:

mcrypt_generic_end()

mysql_list_dbs()

4. Changed Functions 变化的自带函数

Several functions were given new, optional parameters in PHP 5.4:

PHP Core:

Added the optional

limit

parameter to debug_backtrace() and debug_print_backtrace(),
to limit the amount of stack frames returned.

is_link() now
works properly for symbolic links on Windows Vista or later. Earlier systems do not support symbolic links.

OpenSSL:

Added a no padding option to the openssl_encrypt() and openssl_decrypt() functions.

Intl:

idn_to_ascii() and idn_to_utf8() now
take two extra parameters, one indicating the variant (IDNA 2003 or UTS #46) and another, passed by reference, to return details about the operation in case UTS #46 is chosen.

5. New Functions 新增的函数

HP 5.4 introduced some new functions:

PHP Core:

hex2bin()

http_response_code()

get_declared_traits()

getimagesizefromstring()

stream_set_chunk_size()

socket_import_stream()

trait_exists()

header_register_callback()

SPL:

class_uses()

Session:

session_status()

session_register_shutdown()

Mysqli:

mysqli_error_list()

mysqli_stmt_error_list()

Libxml:

libxml_set_external_entity_loader()

LDAP:

ldap_control_paged_result()

ldap_control_paged_result_response()

Intl:

transliterator_create()

transliterator_create_from_rules()

transliterator_create_inverse()

transliterator_get_error_code()

transliterator_get_error_message()

transliterator_list_ids()

transliterator_transliterate()

Zlib:

zlib_decode()

zlib_encode()

6 . New Classes and Interfaces 新增的类和接口

The following classes were introduced in PHP 5.4.0:

SPL:

CallbackFilterIterator

RecursiveCallbackFilterIterator

Reflection:

ReflectionZendExtension

Json:

JsonSerializable

Session:

SessionHandler

SessionHandlerInterface

Snmp:

SNMP

Intl:

Transliterator

Spoofchecker

7. New Methods 新增的方法

Several new methods were introduced in 5.4.0:

XSL:

XsltProcessor::setSecurityPrefs()

XsltProcessor::getSecurityPrefs()

SPL:

RegexIterator::getRegex()

SplObjectStorage::getHash()

DirectoryIterator::getExtension()

SplDoublyLinkedList::serialize()

SplDoublyLinkedList::unserialize()

SplFileInfo::getExtension()

SplFileObject::fputcsv()

SplQueue::serialize()

SplQueue::unserialize()

SplStack::serialize()

SplStack::unserialize()

SplTempFileObject::fputcsv()

Reflection:

ReflectionExtension::isPersistent()

ReflectionExtension::isTemporary()

ReflectionClass::isCloneable()

Closure:

Closure::bind()

Closure::bindTo()

PDO_dblib:

PDO::newRowset()

StreamWrapper:

StreamWrapper::stream_metadata()

StreamWrapper::stream_truncate()

8. Removed Extensions 移除扩展sqlite

These extensions have been moved to PECL and are no longer part of the PHP distribution. The PECL package versions of these extensions will be created according to user demand.

sqlite -
Note that ext/sqlite3 and ext/pdo_sqlite are not affected

9 .Other changes to extensions 修改的扩展

Changes in extension behavior, and new features:

mysqli - mysqli_result now
implements Traversable

pdo_mysql -
Removed support for linking with MySQL client libraries older than 4.1

The MySQL extensions mysql, mysqli and PDO_mysql use mysqlnd as
the default library now. It is still possible to use libmysql by specifying a path to the configure options.

mysqlnd -
Added named pipes support

10. New Global Constants 新增的全局常量

PHP Core:

ENT_DISALLOWED

ENT_HTML401

ENT_HTML5

ENT_SUBSTITUTE

ENT_XML1

ENT_XHTML

IPPROTO_IP

IPPROTO_IPV6

IPV6_MULTICAST_HOPS

IPV6_MULTICAST_IF

IPV6_MULTICAST_LOOP

IP_MULTICAST_IF

IP_MULTICAST_LOOP

IP_MULTICAST_TTL

MCAST_JOIN_GROUP

MCAST_LEAVE_GROUP

MCAST_BLOCK_SOURCE

MCAST_UNBLOCK_SOURCE

MCAST_JOIN_SOURCE_GROUP

MCAST_LEAVE_SOURCE_GROUP

Curl:

CURLOPT_MAX_RECV_SPEED_LARGE

CURLOPT_MAX_SEND_SPEED_LARGE

LibXML:

LIBXML_HTML_NODEFDTD

LIBXML_HTML_NOIMPLIED

LIBXML_PEDANTIC

OpenSSL:

OPENSSL_CIPHER_AES_128_CBC

OPENSSL_CIPHER_AES_192_CBC

OPENSSL_CIPHER_AES_256_CBC

OPENSSL_RAW_DATA

OPENSSL_ZERO_PADDING

Output buffering:

PHP_OUTPUT_HANDLER_CLEAN

PHP_OUTPUT_HANDLER_CLEANABLE

PHP_OUTPUT_HANDLER_DISABLED

PHP_OUTPUT_HANDLER_FINAL

PHP_OUTPUT_HANDLER_FLUSH

PHP_OUTPUT_HANDLER_FLUSHABLE

PHP_OUTPUT_HANDLER_REMOVABLE

PHP_OUTPUT_HANDLER_STARTED

PHP_OUTPUT_HANDLER_STDFLAGS

PHP_OUTPUT_HANDLER_WRITE

Sessions:

PHP_SESSION_ACTIVE

PHP_SESSION_DISABLED

PHP_SESSION_NONE

Streams:

STREAM_META_ACCESS

STREAM_META_GROUP

STREAM_META_GROUP_NAME

STREAM_META_OWNER

STREAM_META_OWNER_NAME

STREAM_META_TOUCH

Zlib:

ZLIB_ENCODING_DEFLATE

ZLIB_ENCODING_GZIP

ZLIB_ENCODING_RAW

Intl:

U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR

IDNA_CHECK_BIDI

IDNA_CHECK_CONTEXTJ

IDNA_NONTRANSITIONAL_TO_ASCII

IDNA_NONTRANSITIONAL_TO_UNICODE

INTL_IDNA_VARIANT_2003

INTL_IDNA_VARIANT_UTS46

IDNA_ERROR_EMPTY_LABEL

IDNA_ERROR_LABEL_TOO_LONG

IDNA_ERROR_DOMAIN_NAME_TOO_LONG

IDNA_ERROR_LEADING_HYPHEN

IDNA_ERROR_TRAILING_HYPHEN

IDNA_ERROR_HYPHEN_3_4

IDNA_ERROR_LEADING_COMBINING_MARK

IDNA_ERROR_DISALLOWED

IDNA_ERROR_PUNYCODE

IDNA_ERROR_LABEL_HAS_DOT

IDNA_ERROR_INVALID_ACE_LABEL

IDNA_ERROR_BIDI

IDNA_ERROR_CONTEXTJ

Json:

JSON_PRETTY_PRINT

JSON_UNESCAPED_SLASHES

JSON_NUMERIC_CHECK

JSON_UNESCAPED_UNICODE

JSON_BIGINT_AS_STRING

11. Changes to INI file handling php.ini的设置变化

he following php.ini directives have been removed:

register_globals and register_long_arrays

magic_quotes_gpc, magic_quotes_runtime,
and magic_quotes_sybase

allow_call_time_pass_reference

define_syslog_variables

highlight.bg

session.bug_compat_42 and session.bug_compat_warn

y2k_compliance

safe_mode, safe_mode_gid, safe_mode_include_dir, safe_mode_exec_dir, safe_mode_allowed_env_vars,
and safe_mode_protected_env_vars

The following php.ini directives have been added:

cli.pager and cli.prompt for
CLI SAPI using readline in interactive mode.

cli_server.color to
enable the built-in development web server to use ANSI color coding in terminal output.

max_input_vars -
specifies how many GET/POST/COOKIE input variables may be accepted.

zend.multibyte -
to control the new multibyte support.

zend.script_encoding -
This value will be used unless a "declare(encoding=...)" directive appears at the top of the script.

zend.signal_check -
to check for replaced signal handlers on shutdown.

session.upload_progress.enabled, session.upload_progress.cleanup, session.upload_progress.prefix, session.upload_progress.name, session.upload_progress.freq, session.upload_progress.min_freq

enable_post_data_reading -
When it's disabled, the POST data is not read (and processed)

windows_show_crt_warning -
This directive shows the Windows CRT warnings when enabled. These warnings were displayed by default until now.

The following php.ini. directives have been changed:

session.entropy_file now
defaults to /dev/random or /dev/urandom depending on what has been guessed at compile time.

session.entropy_length now
defaults to 32.

12. Other changes 别的修改

The default character set for htmlspecialchars() and htmlentities() is
now UTF-8, instead of ISO-8859-1. Note that changing your output charset via the default_charset configuration
setting does not affect htmlspecialchars/htmlentities unless you are passing "" (an empty string) as the encoding parameter to your htmlspecialchars()/htmlentities() calls.
Generally we do not recommend doing this because you should be able to change your output charset without affecting the runtime charset used by these functions. The safest approach is to explicitly set the charset on each call to htmlspecialchars() and htmlentities().

E_ALL

now includes

E_STRICT

level
errors in the error_reporting configuration
directive.

SNMP now
has an OOP API. Functions now return

FALSE

on every error condition including SNMP-related
(no such instance, end of MIB, etc). Thus, in particular, breaks previous behavior of get/walk functions returning an empty string on SNMP-related errors. Multi OID get/getnext/set queries are now supported. Dropped
UCD-SNMP compatibility code, consider upgrading to net-snmp v5.3+, Net-SNMP v5.4+ is required for Windows version. In sake of adding support for IPv6 DNS name resolution of remote SNMP agent (peer) is done by extension now, not
by Net-SNMP library anymore.

OpenSSL now
supports AES.

CLI
SAPI doesn't terminate any more on fatal errors when using interactive mode with readline support.

$_SERVER['REQUEST_TIME_FLOAT'] has
been added to include microsecond precision.

Added new hash algorithms: fnv132, fnv164, joaat

Chained string offsets - e.g. $a[0][0] where $a is a string - now work.

Arrays cast from SimpleXMLElement now
always contain all nodes instead of just the first matching node. All SimpleXMLElement children
are now always printed when using var_dump(), var_export() and print_r().

It's now possible to enforce the class' __construct arguments
in an abstract constructor in the base class.