BSD/Linux Computer Tech

Upgrade from PHP5 to PHP7 on Debian

I just did what was documented here but added in case they go away ever.

1 – get the installed packages

dpkg -l | grep php | tee packages.txt

2 – get php 7

sudo apt install php7.3 php7.3-common php7.3-cli 

3 – get the rest of the packages that you got in step 1

4 – uninstall php5

sudo apt-get purge php5*

5 – if you have fpm for web serving point all the things that used to point to




BSD/Linux Computer Tech

squid ad blocking

To block ads using Squid is simple.

Get the list of ad urls:
## get new ad server list
curl -sS -L --compressed "" > /etc/squid/ad_block.txt

Then add this to squid.conf to reference the file and block the urls:
## disable ads ( )
acl ads dstdom_regex "/etc/squid/ad_block.txt"
http_access deny ads
#deny_info TCP_RESET ads

Then, for Mac Ports at least, do this:
sudo port reload squid4

Or for a recent Linux it’d be something like:
sudo service squid4 restart

BSD/Linux Computer Tech

More Exim4

This may not make much sense to others but it’s all the things for setting up Exim4 in Debian that weren’t obvious.

  • Add all the names and ip address to /etc/hosts
  • Add ip address to exim4 files. Copy the other things added from the old server..
  • Edit just the main folder after doing the exim4 dpkg
  • Update /etc/letsencrypt to allow execute on /etc/letsencrypts/archive and live to get rid of the /var/log/exim4/mainlog pem related errors
  • Remember the sasl stuff from Debian’s exim4 setup to let the user login.
Computer Tech

Time Machine cleanup old backups

This is the command to cleanup old backups in Time Machine should you ever need to. Replace with an appropriate path for your backup location. I find it’d best to delete ranges of old backups with the * wildcard as well.

tmutil delete /Volumes/BackupDriveName/Backups.backupdb/MacComputerName/YYYY-MM-DD-HHMMSS/

BSD/Linux Computer Tech

Ad Blocking with DNS

Easy to ad block with your own DNS server if you don’t want to trust adblock or other plugins.

1 – you need a web server to host a blank image

2 – Get blacklist

Get the blacklist from

Choose for the bind 8 config format.

I had to change the file so that the records read like this:

zone "" IN { type master; notify no; file "/etc/bind/"; };

by adding the “IN” between the domain name and the “{ type master ….” part. Use your vi-skills for this.

Give this file a easy name, like ‘blacklist’. Now create a line in /etc/bind/named.conf.local:

include "/etc/bind/blacklist";

Create the null zone file

Create a file /etc/bin/ with the following contents:

$TTL    86400   ; one day

@       IN      SOA (
            2002061000       ; serial number YYMMDDNN
            28800   ; refresh  8 hours
            7200    ; retry    2 hours
            864000  ; expire  10 days
            86400 ) ; min ttl  1 day


@               IN      A
*               IN      A

and replace by your internal domain name and replace by the name of your web server. The above format allow for the use of wildcards. This means that you do not have to care about the subdomains.

Restart bind (Ubuntu version)

service bind9 restart

2 is copied from here for posterity:

3 – use a different DNS source if you want

If you want to use a different DNS server (say you don’t trust your ISP or Google to know every site you query) you can find others here:

And then in /etc/bind/named.conf.options add the forward to the dns servers:

 forwarders {;;;
BSD/Linux Computer Tech

Fetchmail Google SSL Updates

Google appears to update it’s SSL cert nightly which breaks my fetch mail script nightly as well. Here’s a simple python script in case this happens to you!

import ssl
import socket
import hashlib
import sys

addr = ''

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
wrappedSocket = ssl.wrap_socket(sock)

 wrappedSocket.connect((addr, 993))
 response = False
 der_cert_bin = wrappedSocket.getpeercert(True)
 pem_cert = ssl.DER_cert_to_PEM_cert(wrappedSocket.getpeercert(True))

 thumb_md5 = hashlib.md5(der_cert_bin).hexdigest()
 #print("MD5: " + thumb_md5)


cnt = 0

thumb_md5_d = ''

for letter in thumb_md5:
 if cnt%2 == 0 and cnt!=0:
 thumb_md5_d += ':'
 thumb_md5_d += letter
 cnt += 1

thumb_md5_d = thumb_md5_d.upper()

infile = "//home//user//fetchmailrc.tmp"
text = open(infile)

outfile = open('/etc/fetchmailrc', 'w')


for line in text:
 if textToSearch in line:
 line = line.replace( textToSearch, thumb_md5_d )

Where fetchmailrc.tmp is this (in addition to whatever else in your fetchmailrc):

poll protocol IMAP user "" there with password "password" is here nofetchall ssl sslfingerprint 'GOOGLE_FINGERPRINT'

Then you setup a cron job to run it nightly and now you’ve got up to date Google fingerprints!

BSD/Linux Computer Tech

ZFS fix with Debian upgrade

Somehow a Debian update broke bfs and I was getting this issue:

The ZFS modules are not loaded.
Try running '/sbin/modprobe zfs' as root to load them.

To reinstall ZFS this worked for me – a compilation of many suggestions so not sure all were necessary but it worked:

apt-get clean
apt-get update
apt-get purge zfs*   --get rid of everything ZFS
apt-get remove spl dkms spl-dkms  --get rid of more ZFS
apt-get autoremove
apt-get install -t jessie-backports zfsutils-linux  --change to whatever your distribution uses

--these commands recompile the libraries if they are still having issues
dkms remove -m zfs -v --all
dkms remove -m spl -v --all
dkms add -m spl -v
dkms add -m zfs -v
dkms install -m spl -v
dkms install -m zfs -v
Art Computer

AI Created Great Color Names

This tumblr is a fine example of a neural network learning how to name colors and other things.

Art Computer

The Many Neural Grenixes

Klimt Grenix

Kandinsky Grenix

Van Gogh Grenix

Abstract Grenix

Done with mxnet.

BSD/Linux Computer Tech

Updating Tripwire for changes

First, take a look at the report you received or run (and read):

sudo tripwire --check

If everything is OK, run the following command:

sudo tripwire -m u -Z low -r /var/lib/tripwire/report/hostname-timestamp.twr