File truncation

[Anon]

I need a function that automatically truncates a file to only its LAST 9 lines.
However those lines are of VARIABLE size so I cant just use ftruncate. Any tips?

[Anon]

So does that mean that you want to get the last 9 lines of a file and store it as a variable.

$file = file("pathtoyourfile");
$count = count($file);
for ($i=$count-10;$i<=$count;$i++) {
$newarray[] = $file[$i];
}
$string = implode(" ", $newarray);
print $string;

[Anon]

Save the last 9 lines in in an array.
Reopen file file saying fopen(...,"w")
Then rewrite the 9 lines you saved in the array.

Making this multi-user safe via locking or
some other mechanism is left as an exercise
for the reader... :-)

[Anon]

How about?
tail -n 9 $filename >$filename;

Only works in Unix, but...