File locking help please!

[Anon]

Hey!

ok i always use text databases for all my scripts but i see they changed the code for file locking for PHP4 so i need to know if what i'm doing would work in PHP4 and if i am even doing it right in the first place lol...

right now this is how i do my file locking for reading and writing

$fp = fopen($reset_log_file, "w");
flock($fp,2);
$fw = fwrite($fp, $reset_date);
fclose($fp);

and

$fp = fopen($site_log_file, "r");
flock($fp,1);
$reset_list = fread($fp, filesize($site_log_file));
fclose($fp);

that's from a top site list script i wrote
see that here if you're curious http://rpggateway.com/rpg100/

now i'm wondering ok i lick the file for writing, but doesn't that mean it can still be read? and i don't need file locking on when i'm totaly re-writing the file "w or w+" right?

and with PHP4 would the numbers work? i saw on this one scripts code they did this and is this what i should do so file locking would work with both 3 and 4?

$LOCK_EX = 2;
$LOCK_UN = 3;

      $text = implode("\n",$newlines);
      $fp = fopen($logfile,"w");
      flock($fp,$LOCK_EX);
      fwrite($fp,$text);
      flock($fp,$LOCK_UN);
      fclose($fp);

one thing i don't understand... i thought the file locking was automaticly taken off when the file closes so why end it manualy?

if somone can give me details on this it would be very much helpful because i don't want any of my databases to get screwed up 🙂

Thanks

~Blake

[Anon]

In PHP4, the numbers (which did not make much sense) are replaced by constants. Technically that means the numbers should stil work, but for readability the use of constants is much better.

Instead of

flock($fp,2);

or

$LOCK_EX=2;
flock($fp,$LOCK_EX);

you can now simply write

flock($fp,LOCK_EX);

I'm not sure if a lock is removed when the file is closed
Anyway, it is good programming practise to close everything you open, including those things that are closed by the filesystem etc.
Many times, things are closed automatically because so many programmers forget to close them.

And I just have to remark: text databases? Do people still use them? 🙂

[Anon]

Thanks.. but the 1 and 2 should wrok with php4 right? if so then good hehe...

well not many people use text databases at all... i think i'm one of the only ones i know of that uses text databases alone for everything haha... it's what i first started learning and now i can basicly do anything somone can do with a SQL database with no trouble at all... soon i want to move to MySQL, maybe when i get into much bigger projects and also i may convert some of my current scripts over... i havn't leanred MySQL to much yet, to lazy haha...

~Blake

[Anon]

yep i still use them =P

well them and MySQL... i try to program all my progs in text DB first then convert to MySQL... really more people like using my text databased ones rather than MySQL... well at least for the smaller scripts.

~Blake