added example script for RT#118553 - delete ending blank lines

diff --git a/examples/delete_ending_blank_lines.pl b/examples/delete_ending_blank_lines.pl
new file mode 100755 (executable)
index 0000000..7acad2e
--- /dev/null
+++ b/examples/delete_ending_blank_lines.pl
@@ -0,0 +1,99 @@
+#!/usr/bin/perl -w
+use strict;
+
+# Example script for removing trailing blank lines of code from a perl script
+# This is from the examples/ directory of the perltidy distribution and may
+# be modified as needed. 
+
+# This was written in response to RT #118553, "leave only one newline at end of file".
+# Adding the requested feature to perltidy itself would have very undesirable
+# side-effects when perltidy is operated from within an editor. So it is best
+# done with a separate filter script on entire files.
+
+# usage:
+# delete_ending_blank_lines.pl myfile.pl >myfile.new
+# delete_ending_blank_lines.pl <myfile.pl >myfile.new
+use Getopt::Std;
+use Perl::Tidy;
+use IO::File;
+$| = 1;
+use vars qw($opt_h);
+my $usage = <<EOM;
+   usage: $0 filename >outfile
+EOM
+getopts('h') or die "$usage";
+if ($opt_h) { die $usage }
+
+# Make the source for perltidy, which will be a filehandle
+# or just '-' if the source is stdin
+my ($file, $fh, $source);
+if ( @ARGV == 0 ) {
+    $source = '-';
+}
+elsif ( @ARGV == 1 ) {
+    $file = $ARGV[0];
+    $fh = IO::File->new( $file, 'r' );
+    unless ($fh) { die "cannot open '$file': $!\n" }
+    $source = $fh;
+}
+else { die $usage }
+
+# make the callback object
+my $formatter = MyFormatter->new(); 
+
+my $dest;
+
+# start perltidy, which will start calling our write_line()
+my $err=perltidy(
+    'formatter'   => $formatter,     # callback object
+    'source'      => $source,
+    'destination' => \$dest,         # (not really needed)
+    'argv'        => "-npro -se",    # dont need .perltidyrc
+                                     # errors to STDOUT
+);
+if ($err) {
+    die "Error calling perltidy\n";
+}
+$fh->close() if $fh;
+
+package MyFormatter;
+
+my @lines;
+
+sub new {
+    my ($class) = @_;
+    bless {}, $class;
+}
+
+sub write_line {
+
+    # This is called from perltidy line-by-line; we just save lines
+    my $self              = shift;
+    my $line_of_tokens    = shift;
+    push @lines, $line_of_tokens;
+}
+
+# called once after the last line of a file
+sub finish_formatting {
+    my $self = shift;
+
+    # remove all trailing blank lines of code
+    while (my $line_of_tokens = pop(@lines)) {
+        my $line_type         = $line_of_tokens->{_line_type};
+        my $input_line        = $line_of_tokens->{_line_text};
+        if ( $line_type eq 'CODE' ) {
+            chomp $input_line;
+            next unless ($input_line);
+        }
+       push @lines, $line_of_tokens; 
+       last;
+    }
+
+    # write remaining lines
+    foreach my $line_of_tokens (@lines) {
+        my $line_type         = $line_of_tokens->{_line_type};
+        my $input_line        = $line_of_tokens->{_line_text};
+       print $input_line;
+    }
+    return;
+}