phpversion
The other problem with the code from av01 at bugfix dot cc is that
the behaviour is as per the comments here, not there:
<?php
putenv('MYVAR='); // set MYVAR to an empty value. It is in the environment
putenv('MYVAR'); // unset MYVAR. It is removed from the environment
?>
putenv
(PHP 4, PHP 5)
putenv — Imposta il valore di una variabile d'ambiente
Descrizione
void putenv
( string $setting
)
Imposta una variable nell'ambiente del server. La variabile d'ambiente esisterà solo per lòa durata dsello script Alla fine di questo l'ambiente sarà ripristinato allo stato originario.
L'impostazione di certe variabili d'ambiente può causare dei problemi di sicurezza. La direttiva safe_mode_allowed_env_vars contiene un'elenco separato da virgole di prefissi. In Mpodlità Sicura, l'utente può soltanto alterare le variabili d'ambiente il cui nome inizia con il prefisso indicato da questa direttiva. Per default, gli utenti sono abilitati ad impostare le variabili d'ambiente con inizino con PHP_ (ad esempio PHP_FOO=BAR). Nota: Se questa direttiva è vuota, il PHP permetterà all'utente di modificare QUALSIASI variabile d'ambiente!
La direttiva safe_mode_protected_env_vars contiene un elenco separato da virgola di variabili d'ambiente, che l'utente non può modificare tramite putenv(). Questa variabili saranno protette anche se safe_mode_allowed_env_vars autorizza la modifica a queste.
Avviso
Queste impostazioni hanno effetto soltanto se safe-mode è impostato!
Example #1 Impostazione di una variabile d'ambiente
<?php
putenv("UNIQID=$uniqid");
?>
Vedere anche getenv().
add a note
User Contributed Notesputenv
JM
17-Feb-2007 04:41
17-Feb-2007 04:41
povaddict
05-Jun-2006 03:18
05-Jun-2006 03:18
av01 at bugfix dot cc:
"putenv('MYVAR='); // unset, otherwise this will pass when run the next time"
it won't pass when run next time, "At the end of the request the environment is restored to its original state."
av01 at bugfix dot cc
03-Oct-2005 05:32
03-Oct-2005 05:32
Please be aware, that using putenv() does NOT effect the superglobal $_ENV[] variable. If you want to, set it seperately
<?php
putenv('MYVAR=hello');
assert(getenv('MYVAR') == 'hello'); // passes
assert($_ENV['MYVAR'] == 'hello'); // fails!
putenv('MYVAR='); // unset, otherwise this will pass when run the next time
?>
Iavor
08-Feb-2005 12:06
08-Feb-2005 12:06
Compare to apache_setenv() and apache_getenv().
I had a case setting an env var in VirtualHost which I tried to change with putenv() - but did not work.
apache_setenv() worked.
cap at capsi dot com
28-Mar-2003 08:18
28-Mar-2003 08:18
I've been using putenv with PHP 4.3.1 and Apache 2.0.44, but it does not seem to restore variables correctly. I'm getting +0100 and -0800 entries all across my Apache logs. Manually adding a putenv in page footers to restore the original value seems to fix things, but I still wish I could set the time zone for a specific request only.
I'm not sure whether using putenv affects all threads within the process, that could be another problem.
verkoop at it-design dot com
08-Mar-2001 01:19
08-Mar-2001 01:19
for those who have problems with the putenv ('TZ=Europe/Amsterdam').
I found that there is a solution/work-a-round. It will work, but only if you add mktime(0,0,0,1,1,1970) on the next line. So:
<?php
putenv ('TZ=Europe/Amsterdam');
mktime(0,0,0,1,1,1970)
echo date("H:i:s");
?>
david dot boyce at messagingdirect dot comnospam
14-Sep-2000 08:23
14-Sep-2000 08:23
Environment variables are part of the underlying operating system's
way of doing things, and are used to pass information between a parent
process and its child, as well as to affect the way some internal
functions behave. They should not be regarded as ordinary PHP
variables.
A primary purpose of setting environment variables in a PHP script is
so that they are available to processes invoked by that script using
e.g. the system() function, and it's unlikely that they would need to
be changed for other reasons.
For example, if a particular system command required a special value
of the environment variable LD_LIBRARY_PATH to execute successfully,
then the following code might be used on a *NIX system:
<?php
$saved = getenv("LD_LIBRARY_PATH"); // save old value
$newld = "/extra/library/dir:/another/path/to/lib"; // extra paths to add
if ($saved) { $newld .= ":$saved"; } // append old paths if any
putenv("LD_LIBRARY_PATH=$newld"); // set new value
system("mycommand -with args"); // do system command;
// mycommand is loaded using
// libs in the new path list
putenv("LD_LIBRARY_PATH=$saved"); // restore old value
?>
It will usually be appropriate to restore the old value after use;
LD_LIBRARY_PATH is a particularly good example of a variable which it
is important to restore immediately, as it is used by internal
functions.
If php.ini configuration allows, the values of environment variables
are made available as PHP global variables on entry to a script, but
these global variables are merely copies and do not track the actual
environment variables once the script is entered. Changing
$REMOTE_ADDR (or even $HTTP_ENV_VARS["REMOTE_ADDR"]) should not be
expected to affect the actual environment variable; this is why
putenv() is needed.
Finally, do not rely on environment variables maintaining the same
value from one script invocation to the next, especially if you have
used putenv(). The result depends on many factors, such as CGI vs
apache module, and the exact way in which the environment is
manipulated before entering the script.