预定义常量

下列常量作为 PHP 核心的一部分总是可用的。

注意: 你可以使用它们在 php.ini 中的常量名称; 但是在 PHP 之外，例如在 httpd.conf 之中, 你必须使用二进制位掩码来代替。

**错误和日志记录**
值	常量	说明
1	`E_ERROR` (int)	致命的运行时错误。这类错误一般是不可恢复的情况，例如内存分配导致的问题。后果是导致脚本终止不再继续运行。
2	`E_WARNING` (int)	运行时警告 (非致命错误)。仅给出提示信息，但是脚本不会终止运行。
4	`E_PARSE` (int)	编译时语法解析错误。解析错误仅仅由分析器产生。
8	`E_NOTICE` (int)	运行时通知。表示脚本遇到可能会表现为错误的情况，但是在可以正常运行的脚本里面也可能会有类似的通知。
16	`E_CORE_ERROR` (int)	在 PHP 初始化启动过程中发生的致命错误。该错误类似 `E_ERROR`，但是是由 PHP 引擎核心产生的。
32	`E_CORE_WARNING` (int)	PHP 初始化启动过程中发生的警告 (非致命错误) 。类似 `E_WARNING`，但是是由 PHP 引擎核心产生的。
64	`E_COMPILE_ERROR` (int)	致命编译时错误。类似 `E_ERROR`，但是是由 Zend 脚本引擎产生的。
128	`E_COMPILE_WARNING` (int)	编译时警告 (非致命错误)。类似 `E_WARNING`，但是是由 Zend 脚本引擎产生的。
256	`E_USER_ERROR` (int)	用户产生的错误信息。类似 `E_ERROR`，但是是由用户自己在代码中使用 PHP 函数 trigger_error()来产生的。
512	`E_USER_WARNING` (int)	用户产生的警告信息。类似 `E_WARNING`，但是是由用户自己在代码中使用 PHP 函数 trigger_error()来产生的。
1024	`E_USER_NOTICE` (int)	用户产生的通知信息。类似 `E_NOTICE`，但是是由用户自己在代码中使用 PHP 函数 trigger_error()来产生的。
2048	`E_STRICT` (int)	启用 PHP 对代码的修改建议，以确保代码具有最佳的互操作性和向前兼容性。
4096	`E_RECOVERABLE_ERROR` (int)	可被捕捉的致命错误。它表示发生了一个可能非常危险的错误，但是还没有导致PHP引擎处于不稳定的状态。如果该错误没有被用户自定义句柄捕获 (参见 set_error_handler())，将成为一个 `E_ERROR`　从而脚本会终止运行。
8192	`E_DEPRECATED` (int)	运行时通知。启用后将会对在未来版本中可能无法正常工作的代码给出警告。
16384	`E_USER_DEPRECATED` (int)	用户产生的警告信息。类似 `E_DEPRECATED`, 但是是由用户自己在代码中使用PHP函数 trigger_error()来产生的。
32767	`E_ALL` (int)	所有错误、警告和通知。

上面的值（数值或者符号）用于建立一个二进制位掩码，来制定要报告的错误信息。可以使用按位运算符来组合这些值或者屏蔽某些类型的错误。请注意，在 php.ini 之中，只有'|', '~', '!', '^' 和 '&' 会正确解析。

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User Contributed Notes 16 notes

down

Andy at Azurite (co uk) ¶

13 years ago

-1 is also semantically meaningless as a bit field, and only works in 2s-complement numeric representations.  On a 1s-complement system -1 would not set E_ERROR.  On a sign-magnitude system -1 would set nothing at all! (see e.g. http://en.wikipedia.org/wiki/Ones%27_complement)

If you want to set all bits, ~0 is the correct way to do it.

But setting undefined bits could result in undefined behaviour and that means *absolutely anything* could happen :-)

down

russthom at fivegulf dot com ¶

12 years ago

[Editor's note: fixed E_COMPILE_* cases that incorrectly returned E_CORE_* strings. Thanks josiebgoode.]



The following code expands on Vlad's code to show all the flags that are set.  if not set, a blank line shows.



<?php

$errLvl = error_reporting();

for ($i = 0; $i < 15;  $i++ ) {

    print FriendlyErrorType($errLvl & pow(2, $i)) . "<br>\\n"; 

}



function FriendlyErrorType($type)

{

    switch($type)

    {

        case E_ERROR: // 1 //

            return 'E_ERROR';

        case E_WARNING: // 2 //

            return 'E_WARNING';

        case E_PARSE: // 4 //

            return 'E_PARSE';

        case E_NOTICE: // 8 //

            return 'E_NOTICE';

        case E_CORE_ERROR: // 16 //

            return 'E_CORE_ERROR';

        case E_CORE_WARNING: // 32 //

            return 'E_CORE_WARNING';

        case E_COMPILE_ERROR: // 64 //

            return 'E_COMPILE_ERROR';

        case E_COMPILE_WARNING: // 128 //

            return 'E_COMPILE_WARNING';

        case E_USER_ERROR: // 256 //

            return 'E_USER_ERROR';

        case E_USER_WARNING: // 512 //

            return 'E_USER_WARNING';

        case E_USER_NOTICE: // 1024 //

            return 'E_USER_NOTICE';

        case E_STRICT: // 2048 //

            return 'E_STRICT';

        case E_RECOVERABLE_ERROR: // 4096 //

            return 'E_RECOVERABLE_ERROR';

        case E_DEPRECATED: // 8192 //

            return 'E_DEPRECATED';

        case E_USER_DEPRECATED: // 16384 //

            return 'E_USER_DEPRECATED';

    }

    return "";

}

?>

down

fadhilinjagi at gmail dot com ¶

2 years ago

A simple and neat way to get the error level from the error code. You can even customize the error level names further.

<?php
$exceptions = [
        E_ERROR => "E_ERROR",
        E_WARNING => "E_WARNING",
        E_PARSE => "E_PARSE",
        E_NOTICE => "E_NOTICE",
        E_CORE_ERROR => "E_CORE_ERROR",
        E_CORE_WARNING => "E_CORE_WARNING",
        E_COMPILE_ERROR => "E_COMPILE_ERROR",
        E_COMPILE_WARNING => "E_COMPILE_WARNING",
        E_USER_ERROR => "E_USER_ERROR",
        E_USER_WARNING => "E_USER_WARNING",
        E_USER_NOTICE => "E_USER_NOTICE",
        E_STRICT => "E_STRICT",
        E_RECOVERABLE_ERROR => "E_RECOVERABLE_ERROR",
        E_DEPRECATED => "E_DEPRECATED",
        E_USER_DEPRECATED => "E_USER_DEPRECATED",
        E_ALL => "E_ALL"
];

echo $exceptions["1"];
$code = 256;
echo $exceptions[$code];
?>

Output:  
E_ERROR
E_USER_ERROR

This will need updating when PHP updates the error level names. Otherwise, it works just fine.

down

paulsnar ¶

6 years ago

PHP 7 makes E_STRICT irrelevant, reclassifying most of the errors as proper warnings, notices or E_DEPRECATED: https://wiki.php.net/rfc/reclassify_e_strict

down

bbrokman at gmail dot com ¶

5 years ago

A neat way to have a place in code to control error reporting configuration :)

<?php

$errorsActive = [
    E_ERROR             => FALSE,
    E_WARNING           => TRUE,
    E_PARSE             => TRUE,
    E_NOTICE            => TRUE,
    E_CORE_ERROR        => FALSE,
    E_CORE_WARNING      => FALSE,
    E_COMPILE_ERROR     => FALSE,
    E_COMPILE_WARNING   => FALSE,
    E_USER_ERROR        => TRUE,
    E_USER_WARNING      => TRUE,
    E_USER_NOTICE       => TRUE,
    E_STRICT            => FALSE,
    E_RECOVERABLE_ERROR => TRUE,
    E_DEPRECATED        => FALSE,
    E_USER_DEPRECATED   => TRUE,
    E_ALL               => FALSE,
];

error_reporting(
    array_sum(
        array_keys($errorsActive, $search = true)
    )
);

?>

down

cl at viazenetti dot de ¶

6 years ago

An other way to get all PHP errors  that are set to be reported. This code will even work, when additional error types are added in future.

<?php
$pot = 0;
foreach (array_reverse(str_split(decbin(error_reporting()))) as $bit) {
    if ($bit == 1) {
        echo array_search(pow(2, $pot), get_defined_constants(true)['Core']). "<br>\n";
    }
    $pot++;
}
?>

down

ali6236 at yahoo dot com ¶

1 year ago

A better way to map error constant to their names (instead of switch) :

    function getErrorName($code)
    {
        static $error_names = [
            E_ERROR => 'E_ERROR',
            E_WARNING => 'E_WARNING',
            E_PARSE => 'E_PARSE',
            E_NOTICE => 'E_NOTICE',
            E_CORE_ERROR => 'E_CORE_ERROR',
            E_CORE_WARNING => 'E_CORE_WARNING',
            E_COMPILE_ERROR => 'E_COMPILE_ERROR',
            E_COMPILE_WARNING => 'E_COMPILE_WARNING',
            E_USER_ERROR => 'E_USER_ERROR',
            E_USER_WARNING => 'E_USER_WARNING',
            E_USER_NOTICE => 'E_USER_NOTICE',
            E_STRICT => 'E_STRICT',
            E_RECOVERABLE_ERROR => 'E_RECOVERABLE_ERROR',
            E_DEPRECATED => 'E_DEPRECATED',
            E_USER_DEPRECATED => 'E_USER_DEPRECATED',
        ];
        return $error_names[$code] ?? '';
    }

down

ahsankhatri1992 at gmail ¶

8 years ago

Notes posted above limited to current errors level as on 26th Aug 2016, following snippet will work even on introduction of new error level

$errLvl = error_reporting(); 
for ( $i = 1; $i < E_ALL;  $i*=2 )
{ 
    print FriendlyErrorType($errLvl & $i) . "<br>\n"; 
}

function FriendlyErrorType($type) 
{ 
    switch($type) 
    { 
        case E_ERROR: // 1 // 
            return 'E_ERROR'; 
        case E_WARNING: // 2 // 
            return 'E_WARNING'; 
        case E_PARSE: // 4 // 
            return 'E_PARSE'; 
        case E_NOTICE: // 8 // 
            return 'E_NOTICE'; 
        case E_CORE_ERROR: // 16 // 
            return 'E_CORE_ERROR'; 
        case E_CORE_WARNING: // 32 // 
            return 'E_CORE_WARNING'; 
        case E_COMPILE_ERROR: // 64 // 
            return 'E_COMPILE_ERROR'; 
        case E_COMPILE_WARNING: // 128 // 
            return 'E_COMPILE_WARNING'; 
        case E_USER_ERROR: // 256 // 
            return 'E_USER_ERROR'; 
        case E_USER_WARNING: // 512 // 
            return 'E_USER_WARNING'; 
        case E_USER_NOTICE: // 1024 // 
            return 'E_USER_NOTICE'; 
        case E_STRICT: // 2048 // 
            return 'E_STRICT'; 
        case E_RECOVERABLE_ERROR: // 4096 // 
            return 'E_RECOVERABLE_ERROR'; 
        case E_DEPRECATED: // 8192 // 
            return 'E_DEPRECATED'; 
        case E_USER_DEPRECATED: // 16384 // 
            return 'E_USER_DEPRECATED'; 
    } 
    return ""; 
}

down

kezzyhko at NOSPAM dot semysha dot ru ¶

8 years ago

As for me, the best way to get error name by int value is that. And it's works fine for me ;)
<?php

array_flip(array_slice(get_defined_constants(true)['Core'], 1, 15, true))[$type];

//the same in readable form
array_flip(
    array_slice(
        get_defined_constants(true)['Core'],
        1,
        15,
        true
    )
)[$type]

?>

down

kaioker ¶

2 years ago

super simple error code to human readable conversion:

function prettycode($code){
    return $code == 0 ? "FATAL" : array_search($code, get_defined_constants(true)['Core']);
}

down

ErikBachmann ¶

5 years ago

A shorter version of vladvarna's FriendlyErrorType($type)
<?php
function getErrorTypeByValue($type) {
    $constants  = get_defined_constants(true);

    foreach ( $constants['Core'] as $key => $value ) { // Each Core constant
        if ( preg_match('/^E_/', $key  ) ) {    // Check error constants
            if ( $type == $value ) 
                return( "$key=$value");
        }
    }
}   // getErrorTypeByValue() 

echo "[".getErrorTypeByValue( 1 ) . "]". PHP_EOL;
echo "[".getErrorTypeByValue( 0 ) . "]". PHP_EOL;
echo "[".getErrorTypeByValue( 8 ) . "]". PHP_EOL;
?>

Will give
    [E_ERROR=1]
    []
    [E_NOTICE=8]

down

Anonymous ¶

8 years ago

My version!
For long list function returns for example "E_ALL without E_DEPRECATED "

function errorLevel()
{
    $levels = array(
        'E_ERROR',
        'E_WARNING',
        'E_PARSE',
        'E_NOTICE',
        'E_CORE_ERROR',
        'E_CORE_WARNING',
        'E_COMPILE_ERROR',
        'E_COMPILE_WARNING',
        'E_USER_ERROR',
        'E_USER_WARNING',
        'E_USER_NOTICE',
        'E_STRICT',
        'E_RECOVERABLE_ERROR',
        'E_DEPRECATED',
        'E_USER_DEPRECATED',
        'E_ALL'
    );
    $excluded = $included = array();
    $errLvl = error_reporting();
    foreach ($levels as $lvl) {
        $val = constant($lvl);
        if ($errLvl & $val) {
            $included []= $lvl;
        } else {
                $excluded []= $lvl;
        }
    }
    if (count($excluded) > count($included)) {
        echo '<br />Consist: '.implode(',', $included);
    } else {
        echo '<br />Consist: E_ALL without '.implode(',', $excluded);
    }
}

down

-2

PhpMyCoder ¶

14 years ago

Well, technically -1 will show all errors which includes any new ones included by PHP. My guess is that E_ALL will always include new error constants so I usually prefer:



<?php

error_reporting(E_ALL | E_STRICT);

?>



Reason being: With a quick glance anyone can tell you what errors are reported. -1 might be a bit more cryptic to newer programmers.

down

-4

vladvarna at gmail dot com ¶

12 years ago

function FriendlyErrorType($type)
    {
        switch($type)
            {
            case E_ERROR: // 1 //
                return 'E_ERROR';
            case E_WARNING: // 2 //
                return 'E_WARNING';
            case E_PARSE: // 4 //
                return 'E_PARSE';
            case E_NOTICE: // 8 //
                return 'E_NOTICE';
            case E_CORE_ERROR: // 16 //
                return 'E_CORE_ERROR';
            case E_CORE_WARNING: // 32 //
                return 'E_CORE_WARNING';
            case E_CORE_ERROR: // 64 //
                return 'E_COMPILE_ERROR';
            case E_CORE_WARNING: // 128 //
                return 'E_COMPILE_WARNING';
            case E_USER_ERROR: // 256 //
                return 'E_USER_ERROR';
            case E_USER_WARNING: // 512 //
                return 'E_USER_WARNING';
            case E_USER_NOTICE: // 1024 //
                return 'E_USER_NOTICE';
            case E_STRICT: // 2048 //
                return 'E_STRICT';
            case E_RECOVERABLE_ERROR: // 4096 //
                return 'E_RECOVERABLE_ERROR';
            case E_DEPRECATED: // 8192 //
                return 'E_DEPRECATED';
            case E_USER_DEPRECATED: // 16384 //
                return 'E_USER_DEPRECATED';
            }
        return $type;
    }

down

-4

damian at thebestisp dot dot dot com ¶

8 years ago

I use this code to help mimic the default error handler, the only difference is that the levels end up being all caps, which I don't care to fix. You could also get rid of the underscores, but again, I don't care :P
Until php starts adding constants starting with E_ that have values overlapping with other E_ constants, this seems to be the shortest way of converting error code integers to strings understandable by meat bags. It will also work with new types, so that's nice.
<?php
function friendly_error_type($type) {
    static $levels=null;
    if ($levels===null) {
        $levels=[];
        foreach (get_defined_constants() as $key=>$value) {
            if (strpos($key,'E_')!==0) {continue;}
            $levels[$value]=substr($key,2);
        }
    }
    return (isset($levels[$type]) ? $levels[$type] : "Error #{$type}");
}
echo friendly_error_type(1); #ERROR
echo friendly_error_type(2); #WARNING
echo friendly_error_type(3); #Error #3
?>
Tested on 5.6.12 and 7.0.3 (The first was by accident, didn't realize I was sshed into production :3)

down

-4

ilpaijin at gmail dot com ¶

7 years ago

The bitmask values relative to the Constant E_ALL is 30719, in case of PHP 5.6.x

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