#!/usr/bin/perl -wTuse strict;use Fcntl ":flock";use CGI;use CGIBook::Error;my $DATA_FILE = "/usr/local/apache/data/tab_delimited_records.txt";my $q       = new CGI;my $name    = $q->param( "name" );my $comment = substr( $q->param( "comment" ), 0, 80 );unless ( $name ) {    error( $q, "Please enter your name." );}open DATA_FILE, ">> $DATA_FILE" or die "Cannot append to $DATA_FILE: $!";flock DATA_FILE, LOCK_EX;seek DATA_FILE, 0, 2;print DATA_FILE encode_data( $name, $comment );close DATA_FILE;print $q->header( "text/html" ),      $q->start_html( "Our Petition" ),      $q->h2( "Thank You!" ),      $q->p( "Thank you for signing our petition. ",             "Your name has been been added below:" ),      $q->hr,      $q->start_table,      $q->tr( $q->th( "Name", "Comment" ) );      open DATA_FILE, $DATA_FILE or die "Cannot read $DATA_FILE: $!";while (<DATA_FILE>) {    my @data = decode_data( $_ );    print $q->tr( $q->td( @data ) );}close DATA_FILE;print $q->end_table,      $q->end_html;sub encode_data {    my @fields = map {        s/\\/\\\\/g;        s/\t/\\t/g;        s/\n/\\n/g;        s/\r/\\r/g;        $_;    } @_;        my $line = join "\t", @fields;    return $line . "\n";}sub decode_data {    my $line = shift;        chomp $line;    my @fields = split /\t/, $line;        return map {        s/\\(.)/$1 eq 't' and "\t" or                $1 eq 'n' and "\n" or                $1 eq 'r' and "\r" or                "$1"/eg;        $_;    } @fields;}