Question

I have a file that I’m using to log IP addresses for a client. They want to keep the last 500 lines of the file. It is on a Linux system with PHP4 (oh no!).

I was going to add to the file one line at a time with new IP addresses. We don’t have access to cron so I would probably need to make this function do the line-limit cleanup as well.

I was thinking either using like exec('tail [some params]') or maybe reading the file in with PHP, exploding it on newlines into an array, getting the last 1000 elements, and writing it back. Seems kind of memory intensive though.

What’s a better way to do this?

Update:

Per @meagar’s comment below, if I wanted to use the zip functionality, how would I do that within my PHP script? (no access to cron)

if(rand(0,10) == 10){
 shell_exec("find . logfile.txt [where size > 1mb] -exec zip {} \;")
}

Will zip enumerate the files automatically if there is an existing file or do I need to do that manually?

Answer 1

The fastest way is probably, as you suggested, to use tail:

passthru("tail -n 500 $filename");

(passthru does the same as exec only it outputs the entire program output to stdout. You can capture the output using an output buffer)

[edit]

I agree with a previous comment that a log rotate would be infinitely better… but you did state that you don’t have access to cron so I’m assuming you can’t do logrotate either.