This function can be used in eval() -- it will halt the eval, but not the script eval"() was called in.
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
__halt_compiler — Beendet die Kompilerausführung
Beendet die Kompilerausführung. Dies kann sinnvoll sein, wenn Daten in PHP-Skripte eingebettet sind, wie z. B. in Installationsdateien.
Die Byteposition, an der die Daten beginnen, kann über die Konstante
__COMPILER_HALT_OFFSET__ ermittelt werden, die
nur definiert ist, wenn die Funktion __halt_compiler()
in der Datei benutzt wird.
Diese Funktion besitzt keine Parameter.
Es wird kein Wert zurückgegeben.
Beispiel #1 Ein __halt_compiler()-Beispiel
<?php
// Datei öffnen
$fp = fopen(__FILE__, 'r');
// Auf den Anfang der Daten positionieren
fseek($fp, __COMPILER_HALT_OFFSET__);
// und diese ausgeben
var_dump(stream_get_contents($fp));
// hier Kompilation beenden
__halt_compiler(); ab hier die eigentlichen Daten (z.B. tar, gz, PHP, etc.)Hinweis:
__halt_compiler() kann nur auf der höchsten Ausführungsebene und nicht innerhalb anderer Funktionen oder Methoden benutzt werden.
This function can be used in eval() -- it will halt the eval, but not the script eval"() was called in.If "__halt_compiler();" appears in a file which is "include"d or "require"d, then the called-in file will be treated as if it physically cuts off at the "__halt_compiler();". In other words, "__halt_compiler();" only affects the physical file it's in, an outer file that pulls it in will continue to execute.__halt_compiler is also useful for debugging. If you need to temporarily make a change that will introduce an error later on, use __halt_compiler to prevent syntax errors. For example:
<?php
if ( $something ):
print 'something';
endif; // endif placed here for debugging purposes
__halt_compiler();
endif; // original location of endif -- would produce syntax error if __halt_compiler was not there
?>I don't exactly know what PHP is doing internally but I don't understand the sanity behind how in token_get_all __halt_compiler is handled.
This is actually valid there:
__halt_compiler/**/ /**/ /**/ /**/ /** */();raw
Normally it pops off just any three tokens so you can have even __halt_compiler***, __halt_compiler))), etc in token _get all.
The weird thing is that is also skips T_OPEN_TAG but in the context __halt_compiler runs in this tag should not be posible. Instead it will pick up < and ? as operators and php as a T_STRING.
It ignores the token at any point so this is also valid:
__halt_compiler()/**/ /**/ /**/ /**/ /** */;raw
When I test this with a php file rather than the tokeniser it works the same.
I can only conclude that PHP/__halt_compiler is pretty weird.
I think this is from attempting to weakly imitate the same syntax handling as in functions (I guess you can put comments/whitespace anywhere). I find it annoying and counter productive though.
Even this is valid:
__halt_compiler// comment\n();raw
A general problem that compound matters is that tokenise wont check whether or not syntax is valid (tokens against each other). When running as PHP you must have ();.Joey, you're wrong saying that __halt_compiler have strange behavior. This structure works exactly the same as any other build in structure like empty or isset (even similarly to functions; at least in tokenizer level).
About T_OPEN_TAG - after one open tag is present you didn't expect other one in current php code section, so tokenizer try to handle this "thing" in other way and it's perfectly normal...Please note that __HALT_COMPILER() must be uppercase if used from a pharstub: https://www.php.net/manual/en/phar.fileformat.stub.phpif you find the value of __COMPILER_HALT_OFFSET__ is highly strange. Maybe...
there are some complier optimization tools, like eAccelator(very old). When the program is pre-complied and cached, the __COMPILER_HALT_OFFSET__ will be 0 = =