🚀 go-pugleaf

In article <44spkk$ipv@rs3.rz.uni-hohenheim.de>, pvr  <pvr> wrote:
|Hi,
|is there an easy way to read a file in reverse order (like tail -x does).
|My problem is that I just need the file contents starting at a pattern
|very near the end of a really long file (yes, it's an access_log :-)     
|and I was wondering if it wouldn't be possible to begin at the end of the
|file to speed up my prog.                                           
|Regarding how quick "tail -1 access_log" is I can't believe this         
|scans the whole file. So, is there a perl solution, too ?
|
|If you have any reply, please send me an E-mail, cause our news server
|deletes the files rather quick (at least quicker than I read them :-(.
|
|Thanks.
|

To: pvr
Subject: Re: reverse file reading
Newsgroups: comp.lang.perl.misc,fj.lang.perl,de.comp.lang.perl
In-Reply-To: <44spkk$ipv@rs3.rz.uni-hohenheim.de>
Organization: State University of New York at Buffalo/Computer Science
Cc: 
Bcc: 

In article <44spkk$ipv@rs3.rz.uni-hohenheim.de> you write:
|Hi,
|is there an easy way to read a file in reverse order (like tail -x does).
|My problem is that I just need the file contents starting at a pattern
|very near the end of a really long file (yes, it's an access_log :-)     
|and I was wondering if it wouldn't be possible to begin at the end of the
|file to speed up my prog.                                           
|Regarding how quick "tail -1 access_log" is I can't believe this         
|scans the whole file. So, is there a perl solution, too ?
|
|If you have any reply, please send me an E-mail, cause our news server
|deletes the files rather quick (at least quicker than I read them :-(.
|
|Thanks.
|


Well, you can view a file in reverse:

@input = reverse <>;

foreach $_ (@input) {

	if (/search pattern/){
		do stuff here
	}
}

hope it help. 

Might also consider the seek command, you could jump forward several K of file
at a time before you start reading. Ask me if you want some help with that.

	-Chris. (stoner@cs.buffalo.edu)
        http://www.cs.buffalo.edu/~stoner