Hi, Friday, March 11, 2005, 6:30:52 PM, you wrote:
KM> -----Original Message----- KM> From: Richard Lynch [mailto:[EMAIL PROTECTED] KM> Sent: Thursday, March 10, 2005 10:14 PM KM> To: Ross Hulford KM> Cc: php-general@lists.php.net KM> Subject: Re: [PHP] incrementing a number from a text file >>> I want to read a number from an external (txt) file and increment it.then >>> save the number back on the text file. >>> I know this is possible but want a simple amd economical way to do this. >> That's what you *THINK* you want to do :-) >> But what happens when *TWO* users hit that same script at exactly the same >> time. KM> <snip> >> This is why so many early "hit counter" scripts back in the day were >> always getting messed up and reset to 0. KM> Donīt increase if counter is not read? >> What you really want, almost for sure, is an SQL database with "sequences" KM> I try NOT to use databases if not nessecary >> You *can* use http://php.net/flock, but even that is a Bad Idea, because >> flock under Un*x is self-imposed -- If some *other* program/script/user >> decides not change that file and doesn't use flock, well, they're not >> STOPPED from doing that. KM> Poor programming? >> flock is therefore all too subject to human fallibility when you re-work, >> re-write, or add more code to your system. KM> Every code is... if You donīt use Your head, the outcome will be...? KM> If U no nothing about SQL, I use a database to a counter, I KM> get a piece of code from a friend "alter table counter KM> auto_increment = 1"; and Iīm curious to see, what it does? KM> Or better: I put my query in a link like <a KM> href="db.php?q=select+*+from+customers">show customers</a> and KM> Iīve got NO clue about the settings in the mysql db, so this gets KM> "funny" KM> <a href="db.php?q=delete+from+customers">show customers</a> KM> <a href="db.php?q=drop+table+customers">show customers</a> KM> *whistle* KM> This _was_ an issue in a company I worked for, along with queries like: KM> Select blablabla FROM t1,t2,t3 KM> WHERE customers LIKE '%$s%' KM> OR name LIKE '%$s%' KM> OR domain LIKE '%$s%' KM> OR email LIKE '%$s%' KM> OR log LIKE '%$s%' KM> AND t1.id = t2.t1_id KM> AND t1.id = t3.t1_id KM> Horror! KM> Kind regards KM> Kim Madsen KM> -- KM> PHP General Mailing List (http://www.php.net/) KM> To unsubscribe, visit: http://www.php.net/unsub.php Sorry to get in late here, try these scripts (probably unix only): //count.php <?php //wait if another process has results.new $x = 5; //5 seconds while($x > 0 && file_exists('results.new')){ sleep(1); clearstatcache(); $x--; } if($x == 0) echo "Hung process detected <br>"; if(file_exists('results')){ $count = intval(trim(file_get_contents('results'))); $count ++; }else{ $count = 1; } $fp = fopen("results.new", "w"); if($fp) { fwrite($fp,$count."\n"); exec("ln -f results results.old"); //incase it is being read exec("mv results.new results"); echo "done count=$count\n"; fclose($fp); } //testing script count.html <html> <head> <title>Counter Test</title> </head> <frameset cols="150,150,150,*" rows="*"> <frame src="count.php" name="c1" frameborder="1"> <frame src="count.php" name="c2" frameborder="1"> <frame src="count.php" name="c3" frameborder="1"> <frame src="count.php" name="c4" frameborder="1"> <noframes> <body bgcolor="#FFFFFF"> <p>need frames</p> </body> </noframes> </frameset> </html> In theory no 2 frames should have the same number.... -- regards, Tom -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
