ch03l04.txt

《Web编程专家指南》

Listing 3.4 Improved version of the counter script.

#!/usr/bin/perl
print "Content-type: text/html\n\n";
($PAGE = $ENV{'DOCUMENT_URI'}) =~ 
s|/|_|g;
unless (-e $PAGE) {
    open(NEW,"> $PAGE");
    print NEW "0";
    print "0";
    close(NEW);
    exit(0); 
    }
open(COUNTER,"+< $PAGE");
flock(COUNTER,2);
$count=<COUNTER>;
seek(COUNTER,0,0);
$count++; 
print "$count"; 
print COUNTER "$count";
flock(COUNTER,8);
close(COUNTER);