How to delete oldest file in a dir

[soundser]

I want to archive the previous 4 backup files in my backup dir and delete the oldest when making a new one, automatically of course! Here's what I have:

$numfile = 0;
$dir = '/home/site/backups/';
if (is_dir($dir)) 
{
   if ($dh = opendir($dir)) 
   {
       while (($file = readdir($dh)) !== false) 
       {
           if(is_file($file)) 
           {            
             $oldest = $file;
                if (filemtime($file) > filemtime($oldest))
               {
                $oldest = $file;
                               }
                 if ($numfile >= 5)
                 {
                  unlink($file);
                 }
             $numfile++;
         }
       }
    closedir($dh);
   }
}
//then run a new backup
// Backup directory without trailing / 
$backup_path = '/home/site/backups; 

echo '<br /><p class="content">Backing up the  database....<br /><br />; 
$exec = system("mysqldump --add-drop-table -c -umyusername -pmypass mydb>$backup_path/backup_".$today.".sql"); 

This doesn't delete anything though, it just keeps adding the new backup to the archive.
Can anyone see trouble with this? Thanks

[Gwaihir]

I avoided having to look at times like that by naming them day of the week instead of today, thus the new one overwrites the one a week old. Posted the script elsewhere on this board.

Did that with a shell script though. Your script makes me wonder about permissions: might the mysqldump be run under your username and thus create files not deletable that easily from php? BTW: there's also a note on using -pmypass in that other thread.

[soundser]

I avoided having to look at times like that by naming them day of the week instead of today, thus the new one overwrites the one a week old. Posted the script elsewhere on this board.

Did that with a shell script though. Your script makes me wonder about permissions: might the mysqldump be run under your username and thus create files not deletable that easily from php? BTW: there's also a note on using -pmypass in that other thread.

You will make me wade thru your 303 posted threads to find that message...

This is easier and seems to work:

/*this section works but it would be better to sort the array
using filemtime($file) if I could figure out how */
$files = array();
$dir = '/home/mysite/backups/';
if (is_dir($dir)) 
{
   if ($dh = opendir($dir)) 
   {
       while (($file = readdir($dh)) !== false ) 
       {
         if ($file != "." && $file != "..") 
         {
             array_push($files, $file);
         }
       }
    closedir($dh);
   }
}
rsort($files);
//this section should delete oldest files and keep the newest 5 files
//the array should be sorted in ascending order by sort() because all
//the files are namedlike so: 'backup-mydb_2005-06-04.sql' etc.
$i = 1;
foreach($files as $file)
{
if ($i >= 5){ unlink($dir.'/'.$file); }
 ++$i;
}
// Backup directory without trailing / 
$backup_path = '/home/mysite/backups/'; 

echo '<br /><p class="content">Backing up the database....<br /><br />'; 
$exec = system("mysqldump --add-drop-table -c -umyuser -pmypass mydb >$backup_path/backup_".$today.".sql"); 

I don't have trouble deleting files, it seems. What's the note on using -pmypass in that other thread?
Thanks.

[Gwaihir]

You will make me wade thru your 303 posted threads to find that message...

http://forums.jaguarpc.com/showthread.php?p=81970

Sorry; in my mind it was so alike that I thought it would be easy to find with a keyword or two. Perhaps I should not have hidden it under "cron jobs".

The thing about the password parameter the way you use it is that it makes your password visible in the process list. Won't likely get you hacked tomorrow, but not exactly best practice either.