php捕捉错误的方法：1、使用“try{}catch()”方法捕捉错误；2、通过“set_error_handler”函数捕捉“E_NOTICE”等；3、利用“set_exception_handler”设置默认的异常处理程序。
php错误及异常捕捉
在实际开发中，错误及异常捕捉仅仅靠try{}catch()是远远不够的。
所以引用以下几中函数。
a) set_error_handler
一般用于捕捉 E_NOTICE 、E_USER_ERROR、E_USER_WARNING、E_USER_NOTICE
不能捕捉：
E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR and E_COMPILE_WARNING。
一般与trigger_error("...", E_USER_ERROR)，配合使用。
<?php// we will do our own error handlingerror_reporting(0);function userErrorHandler($errno, $errmsg, $filename, $linenum, $vars){ // timestamp for the error entry $dt = date("Y-m-d H:i:s (T)"); // define an assoc array of error string // in reality the only entries we should // consider are E_WARNING, E_NOTICE, E_USER_ERROR, // E_USER_WARNING and E_USER_NOTICE $errortype = array ( E_ERROR => 'Error', E_WARNING => 'Warning', E_PARSE => 'Parsing Error', E_NOTICE => 'Notice', E_CORE_ERROR => 'Core Error', E_CORE_WARNING => 'Core Warning', E_COMPILE_ERROR => 'Compile Error', E_COMPILE_WARNING => 'Compile Warning', E_USER_ERROR => 'User Error', E_USER_WARNING => 'User Warning', E_USER_NOTICE => 'User Notice', E_STRICT => 'Runtime Notice', E_RECOVERABLE_ERROR => 'Catchable Fatal Error' ); // set of errors for which a var trace will be saved $user_errors = array(E_USER_ERROR, E_USER_WARNING, E_USER_NOTICE); $err = "<errorentry>n"; $err .= "t<datetime>" . $dt . "</datetime>n"; $err .= "t<errornum>" . $errno . "</errornum>n"; $err .= "t<errortype>" . $errortype[$errno] . "</errortype>n"; $err .= "t<errormsg>" . $errmsg . "</errormsg>n"; $err .= "t<scriptname>" . $filename . "</scriptname>n"; $err .= "t<scriptlinenum>" . $linenum . "</scriptlinenum>n"; if (in_array($errno, $user_errors)) { $err .= "t<vartrace>" . wddx_serialize_value($vars, "Variables") . "</vartrace>n"; } $err .= "</errorentry>nn";echo $err;}function distance($vect1, $vect2) { if (!is_array($vect1) || !is_array($vect2)) { trigger_error("Incorrect parameters, arrays expected", E_USER_ERROR); return NULL; } if (count($vect1) != count($vect2)) { trigger_error("Vectors need to be of the same size", E_USER_ERROR); return NULL; } for ($i=0; $i<count($vect1); $i++) { $c1 = $vect1[$i]; $c2 = $vect2[$i]; $d = 0.0; if (!is_numeric($c1)) { trigger_error("Coordinate $i in vector 1 is not a number, using zero",E_USER_WARNING); $c1 = 0.0; } if (!is_numeric($c2)) { trigger_error("Coordinate $i in vector 2 is not a number, using zero",E_USER_WARNING); $c2 = 0.0; }$d += $c2*$c2 - $c1*$c1; } return sqrt($d);} $old_error_handle = set_error_handler("userErrorHandler");$t = I_AM_NOT_DEFINED;//generates a warning // define some "vectors"$a = array(2, 3, "foo");$b = array(5.5, 4.3, -1.6);$c = array(1, -3); //generate a user error$t1 = distance($c,$b); // generate another user error$t2 = distance($b, "i am not an array") . "n"; // generate a warning$t3 = distance($a, $b) . "n";?>
b) set_exception_handler
设置默认的异常处理程序，用于没有用 try/catch 块来捕获的异常。 在 exception_handler 调用后异常会中止。
与throw new Exception('Uncaught Exception occurred')，连用。
<?php// we will do our own error handlingerror_reporting(0);function exceptHandle($errno, $errmsg, $filename, $linenum, $vars){ // timestamp for the error entry $dt = date("Y-m-d H:i:s (T)"); // define an assoc array of error string // in reality the only entries we should // consider are E_WARNING, E_NOTICE, E_USER_ERROR, // E_USER_WARNING and E_USER_NOTICE $errortype = array ( E_ERROR => 'Error', E_WARNING => 'Warning', E_PARSE => 'Parsing Error', E_NOTICE => 'Notice', E_CORE_ERROR => 'Core Error', E_CORE_WARNING => 'Core Warning', E_COMPILE_ERROR => 'Compile Error', E_COMPILE_WARNING => 'Compile Warning', E_USER_ERROR => 'User Error', E_USER_WARNING => 'User Warning', E_USER_NOTICE => 'User Notice', E_STRICT => 'Runtime Notice', E_RECOVERABLE_ERROR => 'Catchable Fatal Error' ); // set of errors for which a var trace will be saved $err = "<errorentry>n"; $err .= "t<datetime>" . $dt . "</datetime>n"; $err .= "t<errornum>" . $errno . "</errornum>n"; $err .= "t<errortype>" . $errortype[$errno] . "</errortype>n"; $err .= "t<errormsg>" . $errmsg . "</errormsg>n"; $err .= "t<scriptname>" . $filename . "</scriptname>n"; $err .= "t<scriptlinenum>" . $linenum . "</scriptlinenum>n"; if (1) { $err .= "t<vartrace>" . wddx_serialize_value($vars, "Variables") . "</vartrace>n"; } $err .= "</errorentry>nn";echo $err;}$old_except_handle = set_exception_handler("exceptHandle");//$t = I_AM_NOT_DEFINED;//generates a warning$a;throw new Exception('Uncaught Exception occurred'); ?>
c) register_shutdown_function
执行机制是：php把要调用的函数调入内存。当页面所有ＰＨＰ语句都执行完成时，再调用此函数。
一般与trigger_error("...", E_USER_ERROR)，配合使用。
<?phperror_reporting(0);date_default_timezone_set('Asia/Shanghai');register_shutdown_function('my_exception_handler'); $t = I_AM_NOT_DEFINED;//generates a warningtrigger_error("Vectors need to be of the same size", E_USER_ERROR); function my_exception_handler(){ if($e = error_get_last()) { //$e['type']对应php_error常量 $message = ''; $message .= "出错信息:t".$e['message']."nn"; $message .= "出错文件:t".$e['file']."nn"; $message .= "出错行数:t".$e['line']."nn"; $message .= "tt请工程师检查出现程序".$e['file']."出现错误的原因n"; $message .= "tt希望能您早点解决故障出现的原因<br/>";echo $message; //sendemail to }}?>c) restore_error_handler()函数
定义和用法 restore_error_handler() 函数恢复之前的错误处理程序，该程序是由 set_error_handler() 函数改变的。
该函数永远返回 true。
是 set_error_handler()的反函数。
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