Re: Overwriting specific lines in text files without rewriting the whole thing.

Thanks all for your ideas and suggestions. I've decided to implement it as a dbm... works pretty well, too. ----- Original Message ----- From: Carroll Barrett <cbarrett@inalt.com> To: <php-general@lists.php.net> Sent: Monday, June 26, 2000 5:43 PM Subject: Re: [PHP-GENERAL] Overwriting specific lines in text files without rewriting the whole thing. > John, > > Suggestion #2: > > $length=9; // largest possible # of digits in counter (set to > what you want) > $id=$unique_id_for_this_page; // first id should be 0 > $fp=fopen("/path/to/counterfile","+r"); > fseek($fp,$length * $id); // position to counter for this page > flock($fp,2); // exclusive lock on file > $count=fread($fp,$length); // get it > fseek($fp,$length * $id); // re-position > fwrite($fp,sprintf("%${length}d",$count + 1); // put new counter > back, hopefully with a fixed length > flock($fp,3); // release lock > fclose($fp); > > Assumptions: > 1) You can assign a unique integer each page > 2) Counter file exists and is filled with enough zeros to allow > for all counters. If you have 1100 pages, then you must have at > least 9 * 1100 = 9900 zeros. > 3) flock($fp,2) will wait for a lock if someone else has locked > the file > 4) All my syntax is correct (a drastic assumption, especially on > the fwrite() line) > > HTH again, > Carroll Barrett > > -----Original Message----- > From: John Biesnecker <amraam@ao.net> > To: php-general@lists.php.net <php-general@lists.php.net> > Date: Monday, June 26, 2000 4:19 PM > Subject: Re: [PHP-GENERAL] Overwriting specific lines in text > files without rewriting the whole thing. > > > >Unfortunately, I have something like 1100 pages, if you count > all of the > >dynamically generated pages... I'm sure it's possible, and I > think I could > >do it in C or something, but I've looked over the PHP filesystem > functions a > >bunch and can't see it... > > > >/s/ John > > > >----- Original Message ----- > >From: Carroll Barrett <cbarrett@inalt.com> > >To: <php-general@lists.php.net> > >Sent: Monday, June 26, 2000 5:02 PM > >Subject: Re: [PHP-GENERAL] Overwriting specific lines in text > files without > >rewriting the whole thing. > > > > > >> John, > >> > >> You might consider having a separate counter file for each > page, > >> if you don't have too many pages. > >> > >> Regards, > >> Carroll Barrett > >> > >> -----Original Message----- > >> From: John Biesnecker <amraam@ao.net> > >> To: php-general@lists.php.net <php-general@lists.php.net> > >> Date: Monday, June 26, 2000 3:48 PM > >> Subject: [PHP-GENERAL] Overwriting specific lines in text > files > >> without rewriting the whole thing. > >> > >> > >> I have created rather simple file-based page hit counter for > my > >> site (because I can't use SQL or anything else). Currently I > am > >> reading the entire thing into an array using file(), finding > the > >> correct line, editing it and writing the entire thing back > into a > >> file. > >> > >> After a few weeks of content development, however, my counter > >> data file has gotten very large, and reading and writing the > >> entire file is beginning to take a noticable amount of time. > I'm > >> already sorting the file so the most accessed pages are on > top, > >> hoping to reduce time needed to find the correct entry. > >> > >> I'm wondering if there is a way that while reading the file > line > >> by line and I can alter a single line and write it back to the > >> file without disturbing the rest of the lines and then exit. > >> Also, if there is, will I see any performance improvement > worth > >> the code rewrite. > >> > >> Thanks. > >> > >> > >> > >> -- > >> PHP General Mailing List (http://www.php.net/) > >> To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net > >> For additional commands, e-mail: > php-general-help@lists.php.net > >> To contact the list administrators, e-mail: > php-list-admin@lists.php.net > >> > > > > > >-- > >PHP General Mailing List (http://www.php.net/) > >To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net > >For additional commands, e-mail: php-general-help@lists.php.net > >To contact the list administrators, e-mail: > php-list-admin@lists.php.net > > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net > For additional commands, e-mail: php-general-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net >