Re: [PHP] use of @ operator to suppress errors
Hello Ben, Monday, March 15, 2004, 11:43:24 AM, you wrote: BJ For example if I refer to $_GET['this'] when there is no 'this' querystring BJ key then i get the error. BJ I've tried using @$_GET['this'] but it makes no difference. BJ Is this normal? Yes because @ suppresses the errors on function calls, not variables (which is all $_GET['this'] is). It's like saying @$this - i.e. as you can see, it doesn't make sense. -- Best regards, Richard Davey http://www.phpcommunity.org/wiki/296.html -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] use of @ operator to suppress errors
Yes, it's normal. You've to check if is that variable set if (isset($_GET['this'])) and than you didn't get any NOTICE about that undefined variable. condition if ($_GET['this']) is not sufficient to check whether is variable set or not. /tom On Mon, 15 Mar 2004 11:43:24 - Ben Joyce [EMAIL PROTECTED] wrote: hi. i'm using error_reporting(0) and set_error_handler(MyErrorHandler) to manage my errors but I'm getting situations where a NOTICE error is thrown. For example if I refer to $_GET['this'] when there is no 'this' querystring key then i get the error. I've tried using @$_GET['this'] but it makes no difference. Is this normal? Thanks in advance. Ben p.s. PHP 4.3.4 on Windows 2003 -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] use of @ operator to suppress errors
Ben Joyce wrote: i'm using error_reporting(0) and set_error_handler(MyErrorHandler) to manage my errors but I'm getting situations where a NOTICE error is thrown. For example if I refer to $_GET['this'] when there is no 'this' querystring key then i get the error. I've tried using @$_GET['this'] but it makes no difference. Is this normal? Yes it is. When you use set_error_handler all errors, warnings and notices cause your handler to be called. To detect the use of the @ prefix check the value of error_reporting in your handler - it will be 0 if @ has been used. Richard Davey wrote: Yes because @ suppresses the errors on function calls, not variables (which is all $_GET['this'] is). On the contrary, the @ prefix suppresses all errors for the block of code it precedes where a block is a function or variable. Essentially it sets error_reporting to 0 while it evaluates that block. -- Stuart -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] use of @ operator to suppress errors
Richard, Tom, and Stuart... thanks for your responses much appreciated. I shall now go and fiddle. Cheers, Ben - Original Message - From: Tom Meinlschmidt [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, March 15, 2004 12:01 PM Subject: Re: [PHP] use of @ operator to suppress errors Yes, it's normal. You've to check if is that variable set if (isset($_GET['this'])) and than you didn't get any NOTICE about that undefined variable. condition if ($_GET['this']) is not sufficient to check whether is variable set or not. /tom On Mon, 15 Mar 2004 11:43:24 - Ben Joyce [EMAIL PROTECTED] wrote: hi. i'm using error_reporting(0) and set_error_handler(MyErrorHandler) to manage my errors but I'm getting situations where a NOTICE error is thrown. For example if I refer to $_GET['this'] when there is no 'this' querystring key then i get the error. I've tried using @$_GET['this'] but it makes no difference. Is this normal? Thanks in advance. Ben p.s. PHP 4.3.4 on Windows 2003 -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] use of @ operator to suppress errors
Hmm. I'm confused. This page... http://uk.php.net/manual/en/language.operators.errorcontrol.php ...says that you can prepend the @ operator to a variable. So with @$_GET['this'] it should suppress the NOTICE error if 'this' doesn't exist. I've done some testing: Test #1 error_reporting(E_ALL); echo $_GET['test']; This generates an on-screen error. Test #2 error_reporting(E_ALL); echo @$_GET['test']; The error is suppressed. If I elect to use a custom error handler then i always get an error generated. It makes no difference what the error level is or whether I use the @ operator. set_error_handler(CustomErrorHandler); error_reporting(E_ALL); echo @$_GET['test']; set_error_handler(CustomErrorHandler); error_reporting(0); echo @$_GET['test']; set_error_handler(CustomErrorHandler); error_reporting(E_ALL); echo $_GET['test']; set_error_handler(CustomErrorHandler); error_reporting(0); echo $_GET['test']; They all have the same result. I suppose I could handle this in my error handling function, ignoring any NOTICE errors, but ideally I'd like to leave it as-is and suppress them when referencing. I'm not sure if I'm making much sense. Any help appreciated! Cheers, Ben - Original Message - From: Stuart [EMAIL PROTECTED] To: Ben Joyce [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Monday, March 15, 2004 12:11 PM Subject: Re: [PHP] use of @ operator to suppress errors Ben Joyce wrote: i'm using error_reporting(0) and set_error_handler(MyErrorHandler) to manage my errors but I'm getting situations where a NOTICE error is thrown. For example if I refer to $_GET['this'] when there is no 'this' querystring key then i get the error. I've tried using @$_GET['this'] but it makes no difference. Is this normal? Yes it is. When you use set_error_handler all errors, warnings and notices cause your handler to be called. To detect the use of the @ prefix check the value of error_reporting in your handler - it will be 0 if @ has been used. Richard Davey wrote: Yes because @ suppresses the errors on function calls, not variables (which is all $_GET['this'] is). On the contrary, the @ prefix suppresses all errors for the block of code it precedes where a block is a function or variable. Essentially it sets error_reporting to 0 while it evaluates that block. -- Stuart -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] use of @ operator to suppress errors
Many Thanks Nikolay. It seems then that if I'm to avoid the NOTICE errors then isset() should be used as suggested earlier. Not the greatest solution but a working one. Thanks to all. Ben - Original Message - From: Nikolay Bachiyski [EMAIL PROTECTED] To: Ben Joyce [EMAIL PROTECTED] Sent: Monday, March 15, 2004 2:32 PM Subject: Re: [PHP] use of @ operator to suppress errors - Original Message - From: Ben Joyce [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, March 15, 2004 2:04 PM Subject: Re: [PHP] use of @ operator to suppress errors Hmm. I'm confused. This page... http://uk.php.net/manual/en/language.operators.errorcontrol.php ...says that you can prepend the @ operator to a variable. So with @$_GET['this'] it should suppress the NOTICE error if 'this' doesn't exist. I've done some testing: Test #1 error_reporting(E_ALL); echo $_GET['test']; This generates an on-screen error. Test #2 error_reporting(E_ALL); echo @$_GET['test']; The error is suppressed. If I elect to use a custom error handler then i always get an error generated. It makes no difference what the error level is or whether I use the @ operator. set_error_handler(CustomErrorHandler); error_reporting(E_ALL); echo @$_GET['test']; set_error_handler(CustomErrorHandler); error_reporting(0); echo @$_GET['test']; set_error_handler(CustomErrorHandler); error_reporting(E_ALL); echo $_GET['test']; set_error_handler(CustomErrorHandler); error_reporting(0); echo $_GET['test']; They all have the same result. I suppose I could handle this in my error handling function, ignoring any NOTICE errors, but ideally I'd like to leave it as-is and suppress them when referencing. I'm not sure if I'm making much sense. Any help appreciated! Cheers, Ben - Original Message - From: Stuart [EMAIL PROTECTED] To: Ben Joyce [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Monday, March 15, 2004 12:11 PM Subject: Re: [PHP] use of @ operator to suppress errors Ben Joyce wrote: i'm using error_reporting(0) and set_error_handler(MyErrorHandler) to manage my errors but I'm getting situations where a NOTICE error is thrown. For example if I refer to $_GET['this'] when there is no 'this' querystring key then i get the error. I've tried using @$_GET['this'] but it makes no difference. Is this normal? Yes it is. When you use set_error_handler all errors, warnings and notices cause your handler to be called. To detect the use of the @ prefix check the value of error_reporting in your handler - it will be 0 if @ has been used. Richard Davey wrote: Yes because @ suppresses the errors on function calls, not variables (which is all $_GET['this'] is). On the contrary, the @ prefix suppresses all errors for the block of code it precedes where a block is a function or variable. Essentially it sets error_reporting to 0 while it evaluates that block. -- Stuart -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php When you are using set_error_handler, the standart PHP error handler is completely bypassed. Both the error_reporting value (saved in php.ini and set by the error_reporting() function) and the @ operator will have no effect onto your handler. Actually the @ error-control operator just sets error_reporting to 0 while the expression to which it is prepeneded is interpreted. Of course you still could fit your handler to use the error_reporting value and take the appropriate action. Regards, Nikolay -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] use of @ operator to suppress errors
On 15 March 2004 12:12, Stuart wrote: Ben Joyce wrote: On the contrary, the @ prefix suppresses all errors for the block of code it precedes where a block is a function or variable. Essentially it sets error_reporting to 0 while it evaluates that block. In fact, to be completely accurate, @ is an operator and suppresses error in the *expression* to which it applies -- this means you can affect what it applies to by using parentheses. Cheers! Mike - Mike Ford, Electronic Information Services Adviser, Learning Support Services, Learning Information Services, JG125, James Graham Building, Leeds Metropolitan University, Beckett Park, LEEDS, LS6 3QS, United Kingdom Email: [EMAIL PROTECTED] Tel: +44 113 283 2600 extn 4730 Fax: +44 113 283 3211 -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
