We also had this challenge in our company to prevent a php script in a cron job from overlapping each other.
We made this solution
<?php
// Initialize variables
$found = 0;
$file = basename(__FILE__);
$commands = array();
// Get running processes.
exec("ps w", $commands);
// If processes are found
if (count($commands) > 0) {
foreach ($commands as $command) {
if (strpos($command, $file) === false) {
// Do nothin'
}
else {
// Let's count how many times the file is found.
$found++;
}
}
}
// If the instance of the file is found more than once.
if ($found > 1) {
echo "Another process is running.\n";
die();
}
/**
*
* Regular process here...
*
*/
?>
getmypid
(PHP 4, PHP 5)
getmypid — Obtiene el ID del proceso PHP
Descripción
int getmypid
( void
)
Obtiene el ID del proceso PHP actual.
Valores retornados
Devuelve el ID del proceso PHP actual, o FALSE si ocurre un error.
Notes
Warning
Los IDs de proceso no son únicos, por lo tanto son una fuente débil de entropía. Es recomendable no depender en ids de proceso en contextos sujetos a consideraciones de seguridad.
Ver también
- getmygid() - Obtener el GID del dueño del script PHP
- getmyuid() - Obtiene el UID del dueño del script PHP
- get_current_user() - Obtiene el nombre del dueño del script PHP actual
- getmyinode() - Obtiene el inode del script actual
- getlastmod() - Obtiene la hora de la última modificación de la página
getmypid
Erickson Reyes ercbluemonday at yahoo dot com
10-Nov-2009 01:01
10-Nov-2009 01:01
Kevin Traas (ktraas- at -gmail dot com)
25-Sep-2009 08:51
25-Sep-2009 08:51
Looking to create a lock-file mechanism for a cmd-line script?
Enjoy!
#!/usr/bin/php
<?php
define( 'LOCK_FILE', "/var/run/".basename( $argv[0], ".php" ).".lock" );
if( isLocked() ) die( "Already running.\n" );
# The rest of your script goes here....
echo "Hello world!\n";
sleep(30);
unlink( LOCK_FILE );
exit(0);
function isLocked()
{
# If lock file exists, check if stale. If exists and is not stale, return TRUE
# Else, create lock file and return FALSE.
if( file_exists( LOCK_FILE ) )
{
# check if it's stale
$lockingPID = trim( file_get_contents( LOCK_FILE ) );
# Get all active PIDs.
$pids = explode( "\n", trim( `ps -e | awk '{print $1}'` ) );
# If PID is still active, return true
if( in_array( $lockingPID, $pids ) ) return true;
# Lock-file is stale, so kill it. Then move on to re-creating it.
echo "Removing stale lock file.\n";
unlink( LOCK_FILE );
}
file_put_contents( LOCK_FILE, getmypid() . "\n" );
return false;
}
?>
kroczu at interia dot pl
19-Dec-2005 12:59
19-Dec-2005 12:59
<?php
/*
mixed getpidinfo(mixed pid [, string system_ps_command_options])
this function gets PID-info from system ps command and return it in useful assoc-array,
or return false and trigger warning if PID doesn't exists
$pidifo=getpidinfo(12345);
print_r($pidifo);
Array
(
[USER] => user
[PID] => 12345
[%CPU] => 0.0
[%MEM] => 0.0
[VSZ] => 1720
[RSS] => 8
[TT] => ??
[STAT] => Is
[STARTED] => 6:00PM
[TIME] => 0:00.01
[COMMAND] => php someproces.php > logfile
)
*/
//////////////////////////////////////////////
function getpidinfo($pid, $ps_opt="aux"){
$ps=shell_exec("ps ".$ps_opt."p ".$pid);
$ps=explode("\n", $ps);
if(count($ps)<2){
trigger_error("PID ".$pid." doesn't exists", E_USER_WARNING);
return false;
}
foreach($ps as $key=>$val){
$ps[$key]=explode(" ", ereg_replace(" +", " ", trim($ps[$key])));
}
foreach($ps[0] as $key=>$val){
$pidinfo[$val] = $ps[1][$key];
unset($ps[1][$key]);
}
if(is_array($ps[1])){
$pidinfo[$val].=" ".implode(" ", $ps[1]);
}
return $pidinfo;
}
?>
Pure-PHP
21-Mar-2005 10:26
21-Mar-2005 10:26
You can use this function also to avoid more than one instance of your app.
You can also use this class.
http://www.pure-php.de/node/20
Usage:
<?php
inlude("ProcessHandler.class.php");
if(ProcessHandler::isActive()){
die("Already running!\n";);
}else{
ProcessHandler::activate();
//run my app
}
?>
brooke at jump dot net
25-Oct-2003 12:49
25-Oct-2003 12:49
One good use for this is deciding on a concurrency-safe temporary file or directory name. You can be assured that no two processes on the same server have the same PID, so this is enough to avoid collisions. For example:
<?php
$tmpfile = "/tmp/foo_".getmypid();
// Use $tmpfile...
// Use $tmpfile...
// Use $tmpfile...
unlink ($tmpfile);
?>
If you are sharing /tmp over the network (which is odd....) then you can, of course, mix in the PHP server's IP address.
