";
if ($ENV{'REQUEST_METHOD'} eq "POST") {
# get value of form field "ta" and decode
read(STDIN, $query, $ENV{'CONTENT_LENGTH'});
@vars = split(/&/, $query);
foreach $var (@vars) {
($name, $value) = split('=', $var);
if ($name eq 'ta') {
$value =~ y/\+/ /;
$value =~ s/%([\da-f]{1,2})/pack(C,hex($1))/eig;
$ta = "$value";
last;
}
}
# truncate to cover max length
if (length($ta) > $MAX_LENGTH) {
$ta = substr($ta, 0, $MAX_LENGTH);
}
# dumb regexps to replace > < & with character entities
if ($ta) {
$ta =~ s|\&|\&|sg;
$ta =~ s|\>|\>|sg;
$ta =~ s|\<|\<|sg;
}
# lock, write, release text file (works where os supports perl's lock)
open(FH, ">$textfile") or die "can't open $textfile: $!";
flock(FH, 2) or die "can't flock $textfile: $!";
print FH $ta;
close(FH) or die "can't close $textfile: $!";
# use regexed $ta in output area of form
# (note: output doesn't reflect file, if there's a screw-up)
$content=$ta;
} else {
# if GET, read text file
open(FH, "<$textfile") or die "can't open $textfile: $!";
flock(FH, 1) or die "can't flock $textfile: $!";
undef $/;
$content =
$content
";