23rd May 2007
Found a nicely illustrated method for running a background shell command from PHP and continuously checking if the process is still running.
Here's sample code without explanations:
PHP:
-
function run_in_background($Command, $Priority = 0)
-
{
-
if($Priority)
-
$PID =
shell_exec("nohup nice -n $Priority $Command 2> /dev/null & echo $!");
-
else
-
$PID =
shell_exec("nohup $Command 2> /dev/null & echo $!");
-
return($PID);
-
}
-
-
function is_process_running($PID)
-
{
-
exec("ps $PID",
$ProcessState);
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return(count($ProcessState)>=
2);
-
}
To run something like hmmsearch from the HMMER package, you’d do this:
PHP:
-
echo("Running hmmsearch. . .")
-
$ps = run_in_background("hmmsearch $hmmfile $fastafile> $outfile");
-
while(is_process_running($ps))
-
{
-
-
-
-
}
This entry was posted on Wednesday, May 23rd, 2007 at 16:53 and is filed under Links, PHP, Programming.
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June 24th, 2009 at 9:55
function is_process_running($PID)
{
exec("ps $PID", $ProcessState);
return(count($ProcessState)>= 2);
}
IMO, it is more elegant to check for the exit code instead.
June 24th, 2009 at 10:23
Joe,
how would you do that, given the example application above? I see no way of getting exit status from a process which has finished.