exit

Description

void exit ( [string status] )

void exit ( int status )

注: This is not a real function, but a language construct.

注: PHP >= 4.2.0 does NOT print the status if it is an integer.

The exit() function terminates execution of the script. It prints status just before exiting.

If status is an integer, that value will also be used as the exit status. Exit statuses should be in the range 0 to 254, the exit status 255 is reserved by PHP and shall not be used. The status 0 is used to terminate the program successfully.

例子 1. exit() example
<?php $filename = '/path/to/data-file'; $file = fopen($filename, 'r') or exit("unable to open file ($filename)"); ?>

例子 2. exit() status example
<?php //exit program normally exit; exit(); exit(0); //exit with an error code exit(1); exit(0376); //octal ?>

注: The die() function is an alias for exit().

add a note User Contributed Notes

Roumen Semov
17-Feb-2006 03:54


Please note in PHP "exit(0)" or simply "exit" returns true.

Any other value but zero will return false. This is good to know in case you are writing command-line php scripts where you need the result of the php script to determine if the next script will run. Example:

shell> ./my_php_script && echo "It ran successfully!"

If you know my_php_script can break somewhere you could do a conditional with an "exit(-1)" and then if the script breaks the command after the && will not execute.

09-Feb-2006 09:26


The note above is irrelevant, because a simple "return" would  abort the template included by include or include_once!

francois at bonzon dot com
25-May-2005 09:42


With output buffering on, when sending headers that shouldn't have any data after them, be sure to erase the buffer before exit()ing the script! Like this:



<?php

ob_clean();

exit();

?>



If you don't erase the buffer, in case it was not empty, after sending the headers PHP will still send the buffer content to the browser.



I had Firefox show strange behavior with some of my pages, that it took me quite some time to debug. It was simply because my script was returning 304 Not Modified headers along with the start of an HTML page.

chris at artimador dot com
26-Nov-2004 03:01


When using php as a SHELL scripting language, use die() instead of exit(). If using exit in php5, the script will continue to processes conditionals and other shell_exec functions after the die command.

nospam at mydomain dot com
27-Sep-2004 05:12


Using return instead of exit is to prefer when you want the script that you have included inside another script to die but continue to execute the main script.

// Radcliff

emils at tvnet dot lv
23-Aug-2003 11:14


Note, that using exit() will explicitly cause Roxen webserver to die, if PHP is used as Roxen SAPI module. There is no known workaround for that, except not to use exit(). CGI versions of PHP are not affected.

mbostrom at paragee dot com
27-Feb-2003 04:45


In PHP 4.3.1 (and possibly 4.3.0), running scripts from the command line works a lot better.  This is probably because 4.3.x has a whole new CLI mode.



Specifically, exit status is now returned (to the shell) as you would expect.  This is a godsend for writing embedded email processing scripts, as much email infrastructure (fetchmail, qmail, mutt, etc.) is dependant upon correctly returned status codes, and the inability to return a status code (as in PHP 4.2.x) is an insurmountable obstacle.



$_SERVER["argv"] is also always available in 4.3.x, I think, whereas in 4.2.x php.ini could prevent it from being available.



(On the downside, I had to ./configure --without-mysql in order to get 4.3.1 to compile on RedHat 8.0.  Otherwise there was what looked like a fatal compile warning (that I might also have been able to ignore somehow).



The "fatal warning" FYI:

ext/mysql/libmysql/my_tempnam.o: In function `my_tempnam':

ext/mysql/libmysql/my_tempnam.c:103: the use of `tempnam' is dangerous, better use `mkstemp'



Changing the code from tempnam to mkstemp would probably not be overly complicated, but it is non-trivial.)

shaun at NOshatSPAM dot net
09-Aug-2002 07:13


return may be preferable to exit in certain situations, especially when dealing with the PHP binary and the shell.



I have a script which is the recipient of a mail alias, i.e. mail sent to that alias is piped to the script instead of being delivered to a mailbox. Using exit in this script resulted in the sender of the email getting a delivery failure notice. This was not the desired behavior, I wanted to silently discard messages which did not satisfy the script's requirements.



After several hours of trying to figure out what integer value I should pass to exit() to satisfy sendmail, I tried using return instead of exit. Worked like a charm. Sendmail didn't like exit but it was perfectly happy with return. So, if you're running into trouble with exit and other system binaries, try using return instead.

iamfast at tampabay dot rr dot com
14-Jul-2002 11:12


If you are working with images or something of the sort that is not html, and use auto appending, call exit before you close your php tag, so that the footer is not included, corrupting the end of the file.

--Nate

devinemke at devinemke dot com
11-Jan-2002 04:38


If you are using templates with numerous includes then exit() will end you script and your template will not complete (no </table>, </body>, </html> etc...).  Rather than having complex nested conditional logic within your content, just create a "footer.php" file that closes all of your HTML and if you want to exit out of a script just include() the footer before you exit().



for example:



include ('header.php');

blah blah blah 

if (!$mysql_connect) {

echo "unable to connect";

include ('footer.php');

exit;

}

blah blah blah

include ('footer.php');

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