Author Archives: Juan

Securing your website with an SSL certificate

Securing your website with a SSL certificate has become more important. Google has decided this is an important factor in how websites are presented in Chrome.

There are several options for SSL certificates which range from free to thousands of dollars.

A free SSL certificate from Let’s Encrypt will give your site visitors confidence that their information is not leaking to the web when they interact with your site.

In addition to installing the certificate, I recommend redirecting all http traffic to your new https url. This is also a good time to choose a preferred domain, such as
as opposed to

Create pdf thumbnails

This perl script uses ImageMagick to convert the first page of a directory structure of pdf’s into a 600 pixel wide png thumbnail.  The [0] in file.pdf[0] means to convert only the first page.

#!/usr/bin/perl -w
use strict;

my $tmp = `find . -iname '*.pdf'`;
print "$tmp\n";
my @files = split(/\n/, "$tmp");
foreach my $file (@files)
  my $outfile = "${file}.png";
  if (! -f $outfile)
    my $command = "convert -thumbnail 600 '$file\[0\]' '$file.png'\n";
    print $command;
    print "$outfile already exists\n";

Screen Blanking on Linux Consoles

Linux consoles will blank after a few minutes. These are the screens which you get if you type ctrl-alt-f1 through ctrl-alt-f6 when you are logged into x-windows. To disable this behavior, type:

setterm -blank 0