Perl Hit Counter Script Explanation

This script is a basic page hits counter. It stores the hit count in a database table called 'hits'...

• The first line tells Unix this is a Perl program. The second is a comment describing the script.
   #!/usr/local/bin/Perl
 # hits.pl - V1.0 - TGH 26 May 2001
  
  
• This makes the DBI (DataBase Interface) library of functions available.
   use DBI;
  
  
• Connect to the database.
   $dbh = DBI->connect("DBI:mysql:yourname:localhost:3306", 'yourname', 'password');
  
  
• Create the SQL that will increment the counter for the page. The special variable '$_[0]' is the first parameter that was passed to the script - in this case the web page name.
   $statement = "update hits set counter = counter + 1 where page = $_[0]";
 $sth = $dbh->prepare($statement) or print "Can't prepare the SQL\n";
  
  
• This runs the SQL on the database. the variable $rv contains the number of rows inserted!
   $rv = $sth->execute or print "Can't execute the query: $sth->errstr";
 print $rv, " rows inserted\n";
  
  
• Close the 'statement handle' and disconnect from the database.
   $sth->finish;
 $dbh->disconnect;