fopen stream logfile

djkast

Hello,

I'm trying to create a listening script that monitors a logfile, and processes the
new lines written to it. I have successfully been able to with popen().

However, in case of a crash of my script, I cannot have the same logfile re-process
the same data, so I want to use ftell() and fseek() to track byte offset.
The problem is when I use fseek() i get this error:

Warning: fseek(): stream does not support seeking in /root/rlog/livelog on line 23

Is there another solution I can use to perform this. The logfile has extremely high traffic and rolls over once an hour.

$handle = popen($logfile, 'r');

while(!feof($handle)) {
 fseek($handle, $offs);
 $buffer = fgets($handle);
 ob_flush();
 flush();

 //Determine last byte read
 $offs = ftell($handle);
 }

sneakyimp

you might have your processing script manually keep track of how far it has gotten into the log file. when it successfully processes a log entry, perhaps you can write the entry/line/byte number just processed to a database or another file or a cookie or something.

djkast

The Offset value is being read from a file...
Then overwritten with the newest offset, I just didn't include that
code. I need a workaround for jumping to a certain point in the file.

sneakyimp

$last_line = 234;
$current_line=0;
while(!feof($handle)) {
  while ($current_line<$last_line) {
    fgets($handle);
    $current_line++;
  }
  // we should now have skipped all lines up to and including $last_line

  $buffer = fgets($handle);
  ob_flush();
  flush();

  // keep track of last line read...you might want to 
  // store this in a db or file or cookie or persistent place in case of crash.
  $current_line++;
}