Re: [PHP] stream_select() not working on regular files?
On 02/04/2010 06:18 AM, Eric Lee wrote:
On Thu, Feb 4, 2010 at 9:20 AM, Dennis J.denni...@conversis.de wrote:
On 02/04/2010 02:03 AM, Ashley Sheridan wrote:
On Thu, 2010-02-04 at 01:41 +0100, Dennis J. wrote:
Hi,
I'm trying to implement something similar totail -f in php but I'm
running into a problem.
The issue occurs when I've reached the end of the file. From here I
basically have to loop until new lines get appended to the file but I
would
like to respond immediately when then happens. There are three options
that
I can see:
1. Busy-loop
pro: I can process new lines immediately
contra: Excessivley CPU intensive = not a real option
2. add a sleep(1) to the loop
pro: No longer kills the CPU
contra: I might get a 1 second delay until I can process new lines
3. stream_select(array($fh),null,null,1)
pro: sleeps for one second but returns earlier if new data arrives
contra: doesn't seem to work in files?
Method 3 is the preferable one but doesn't seem to work:
$fh = fopen(testfile,r);
$r = array($fh);
while( ($n = stream_select($r,$w=null,$e=null,1)) == 1 ) {
echo fgets($fh);
}
This program will loop forever because stream_select() will always return
1
even at the end of the file.
Is there any other way to accomplish this?
Regards,
Dennis
I thought that once it reached the end of the file, it will return a 0
indicating no new activity?
That's what I thought too but apparently that is not the case.
Although, surely you want the loop to continue forever, so that new
entries added to the end of the file are shown as soon as they appear.
Yes the loop is supposed to continue forever in the final version. In fact
I what I'm trying to get at is a tail -F which means I will repeatedly
reopen the file to check if it has been replaced by a new one. I just
simplified the problem above to get rid of all the additional complexity and
concentrate on the specific problem I have.
My expectation was that once the end of the file is reached (i.e. fgets()
has consumed all lines) stream_select() should wait for 1 second (in the
above example) and if nothing happens with the file in that second it should
return 0. But that doesn't happen.
Dennis
I have just been bulit a simple test script.
It works for me with a feof call if the stream was at end of file.
But I'am not sure that is that what you want !
?php
$fp = fopen('test.xml', 'r');
$arr = array($fp);
$w = $e = null;
while (($result = stream_select($arr, $w, $e, 1)) !== false)
{
$line = fgets($fp);
if (!empty($line))
{
echo $line;
}
else
{
if (feof($fp))
echo 'eof',\n;
fclose($fp);
$fp = null;
break;
}
}
This script terminates before it hits the actual problem.
The issue is that once I've hit the EOF I need to continue the loop using
the stream_select() waiting for new data.
Regards,
Dennis
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Re: [PHP] stream_select() not working on regular files?
Dennis J. wrote:
The issue is that once I've hit the EOF I need to continue the loop
using the stream_select() waiting for new data.
AFAIK you can't; you see stream_select checks to see if something will
be blocked; if EOF is reached it considers this as not blocked; in other
words the second you hit a file EOF stream_select will continue to
instantly return a positive (without the wait of 1 second).
As far as I know every related function will always return the second
EOF is hit; meaning that the -f functionality you want can only be
gained by adding in the sleep (but i think every line reading function
will still instantly return with an empty line) - so maybe you just need
to proc_open to tail -f and read the stream with PHP - as it won't send
an EOF - example:
?php
$stream = popen( 'tail -f access.log' , 'r' );
while( $line = fgets($stream) ) {
echo $line;
}
pclose( $stream ); // won't get here unless an error i guess..
good luck!
Nathan
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[PHP] stream_select() not working on regular files?
Hi,
I'm trying to implement something similar to tail -f in php but I'm
running into a problem.
The issue occurs when I've reached the end of the file. From here I
basically have to loop until new lines get appended to the file but I would
like to respond immediately when then happens. There are three options that
I can see:
1. Busy-loop
pro: I can process new lines immediately
contra: Excessivley CPU intensive = not a real option
2. add a sleep(1) to the loop
pro: No longer kills the CPU
contra: I might get a 1 second delay until I can process new lines
3. stream_select(array($fh),null,null,1)
pro: sleeps for one second but returns earlier if new data arrives
contra: doesn't seem to work in files?
Method 3 is the preferable one but doesn't seem to work:
$fh = fopen(testfile,r);
$r = array($fh);
while( ($n = stream_select($r,$w=null,$e=null,1)) == 1 ) {
echo fgets($fh);
}
This program will loop forever because stream_select() will always return 1
even at the end of the file.
Is there any other way to accomplish this?
Regards,
Dennis
--
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To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] stream_select() not working on regular files?
On Thu, 2010-02-04 at 01:41 +0100, Dennis J. wrote:
Hi,
I'm trying to implement something similar to tail -f in php but I'm
running into a problem.
The issue occurs when I've reached the end of the file. From here I
basically have to loop until new lines get appended to the file but I would
like to respond immediately when then happens. There are three options that
I can see:
1. Busy-loop
pro: I can process new lines immediately
contra: Excessivley CPU intensive = not a real option
2. add a sleep(1) to the loop
pro: No longer kills the CPU
contra: I might get a 1 second delay until I can process new lines
3. stream_select(array($fh),null,null,1)
pro: sleeps for one second but returns earlier if new data arrives
contra: doesn't seem to work in files?
Method 3 is the preferable one but doesn't seem to work:
$fh = fopen(testfile,r);
$r = array($fh);
while( ($n = stream_select($r,$w=null,$e=null,1)) == 1 ) {
echo fgets($fh);
}
This program will loop forever because stream_select() will always return 1
even at the end of the file.
Is there any other way to accomplish this?
Regards,
Dennis
I thought that once it reached the end of the file, it will return a 0
indicating no new activity?
Although, surely you want the loop to continue forever, so that new
entries added to the end of the file are shown as soon as they appear.
Thanks,
Ash
http://www.ashleysheridan.co.uk
Re: [PHP] stream_select() not working on regular files?
On 02/04/2010 02:03 AM, Ashley Sheridan wrote:
On Thu, 2010-02-04 at 01:41 +0100, Dennis J. wrote:
Hi,
I'm trying to implement something similar totail -f in php but I'm
running into a problem.
The issue occurs when I've reached the end of the file. From here I
basically have to loop until new lines get appended to the file but I would
like to respond immediately when then happens. There are three options that
I can see:
1. Busy-loop
pro: I can process new lines immediately
contra: Excessivley CPU intensive = not a real option
2. add a sleep(1) to the loop
pro: No longer kills the CPU
contra: I might get a 1 second delay until I can process new lines
3. stream_select(array($fh),null,null,1)
pro: sleeps for one second but returns earlier if new data arrives
contra: doesn't seem to work in files?
Method 3 is the preferable one but doesn't seem to work:
$fh = fopen(testfile,r);
$r = array($fh);
while( ($n = stream_select($r,$w=null,$e=null,1)) == 1 ) {
echo fgets($fh);
}
This program will loop forever because stream_select() will always return 1
even at the end of the file.
Is there any other way to accomplish this?
Regards,
Dennis
I thought that once it reached the end of the file, it will return a 0
indicating no new activity?
That's what I thought too but apparently that is not the case.
Although, surely you want the loop to continue forever, so that new
entries added to the end of the file are shown as soon as they appear.
Yes the loop is supposed to continue forever in the final version. In fact
I what I'm trying to get at is a tail -F which means I will repeatedly
reopen the file to check if it has been replaced by a new one. I just
simplified the problem above to get rid of all the additional complexity
and concentrate on the specific problem I have.
My expectation was that once the end of the file is reached (i.e. fgets()
has consumed all lines) stream_select() should wait for 1 second (in the
above example) and if nothing happens with the file in that second it
should return 0. But that doesn't happen.
Regards,
Dennis
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Re: [PHP] stream_select() not working on regular files?
On Thu, Feb 4, 2010 at 9:20 AM, Dennis J. denni...@conversis.de wrote:
On 02/04/2010 02:03 AM, Ashley Sheridan wrote:
On Thu, 2010-02-04 at 01:41 +0100, Dennis J. wrote:
Hi,
I'm trying to implement something similar totail -f in php but I'm
running into a problem.
The issue occurs when I've reached the end of the file. From here I
basically have to loop until new lines get appended to the file but I
would
like to respond immediately when then happens. There are three options
that
I can see:
1. Busy-loop
pro: I can process new lines immediately
contra: Excessivley CPU intensive = not a real option
2. add a sleep(1) to the loop
pro: No longer kills the CPU
contra: I might get a 1 second delay until I can process new lines
3. stream_select(array($fh),null,null,1)
pro: sleeps for one second but returns earlier if new data arrives
contra: doesn't seem to work in files?
Method 3 is the preferable one but doesn't seem to work:
$fh = fopen(testfile,r);
$r = array($fh);
while( ($n = stream_select($r,$w=null,$e=null,1)) == 1 ) {
echo fgets($fh);
}
This program will loop forever because stream_select() will always return
1
even at the end of the file.
Is there any other way to accomplish this?
Regards,
Dennis
I thought that once it reached the end of the file, it will return a 0
indicating no new activity?
That's what I thought too but apparently that is not the case.
Although, surely you want the loop to continue forever, so that new
entries added to the end of the file are shown as soon as they appear.
Yes the loop is supposed to continue forever in the final version. In fact
I what I'm trying to get at is a tail -F which means I will repeatedly
reopen the file to check if it has been replaced by a new one. I just
simplified the problem above to get rid of all the additional complexity and
concentrate on the specific problem I have.
My expectation was that once the end of the file is reached (i.e. fgets()
has consumed all lines) stream_select() should wait for 1 second (in the
above example) and if nothing happens with the file in that second it should
return 0. But that doesn't happen.
Dennis
I have just been bulit a simple test script.
It works for me with a feof call if the stream was at end of file.
But I'am not sure that is that what you want !
?php
$fp = fopen('test.xml', 'r');
$arr = array($fp);
$w = $e = null;
while (($result = stream_select($arr, $w, $e, 1)) !== false)
{
$line = fgets($fp);
if (!empty($line))
{
echo $line;
}
else
{
if (feof($fp))
echo 'eof',\n;
fclose($fp);
$fp = null;
break;
}
}
Regards,
Eric,
Regards,
Dennis
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Re: [PHP] stream_select
Damien Churchill schreef: Is there a known issue with using stream_select with apache2 mod_php? I have a script (http://php.pastebin.com/m601965d) that when run with mod_php doesn't work, but when run with php-cgi from the command line works fine. define doesn't work. what exact php apache version? are you using shared hosting thats blocking all sorts of stuff form being done via the apache process? have you checked bugs.php.net for anything resembling your problem? you seem to be trying to connect to an imap server, have you tried the imap_*() functions as an alternative? http://php.net/imap Thanks in advance, Damien -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] stream_select
Is there a known issue with using stream_select with apache2 mod_php? I have a script (http://php.pastebin.com/m601965d) that when run with mod_php doesn't work, but when run with php-cgi from the command line works fine. Thanks in advance, Damien
[PHP] stream_select problem with signals
I'm rewriting an API to access OneWire Net, i have a problem with select
and signals. The class will support both types of sockets, trought BSD
sockets and with streams.
My problem is that when the PHP app is in socket select and a signal
arrives it threat it as a error, so i can fix in socket_select using
socket_last_error in this form:
$n = socket_select($_read, $_write, $_except, $sec, $usec);
if($n === false) {
if(socket_last_error($this-_sock) == 0) {
// signal break the select
$timeout -= (microtime(true) - $start);
} else {
// Error, not interrupted by signal
return false;
}
} else {
return $n;
}
This work, but i can't determine if a signal interrupted the
stream_select, there is a way to detect this?
Regards.
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